aviation manual chevron-texaco

Global Aviation

Equipment Specifications

Manual

Copy No. ______

Global Aviation Equipment Specifications Manual

Date of Issue: June 2004 Table of Contents Revision Number: Original Issue Page 1

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TABLE OF CONTENTS Introduction Terminal Applications Intermediate Depot Applications Airport Depot Applications

1.0 STORAGE TANKS

2.0 TANK APPURTENANCES 2.1 VALVES 2.2 TANK VENTS 2.3 TANK FLOATING SUCTIONS 2.4 FAST FLUSH FACILITIES 2.5 INTERNAL COATINGS

3.0 PIPEWORK 3.1 DESIGN AND INSTALLATION STANDARDS 3.2 EQUIPMENT MARKING FOR PRODUCT IDENTIFICATION 3.3 TRUCK/REFUELER LOADING & UNLOADING FACILITIES 3.4 REFUELING EQUIPMENT FLOW TEST RIGS

4.0 FILTERS 4.1 STRAINERS 4.2 MICRONIC FILTERS 4.3 FILTER/SEPARATOR INSTALLATIONS 4.4 FILTER/MONITORS

5.0 HYDRANT SYSTEMS 5.1 HYDRANT SYSTEM DESIGN PRINCIPLES 5.2 HYDRANT PITS AND PIT VALVES 5.3 HYDRANT PUMP CONTROL SYSTEMS 5.4 FLUSHING PROCEDURES



5.5 HYDRANT SYSTEM LOW POINTS

6.0 ANCILLARY EQUIPMENT 6.1 AIRCRAFT REFUELING HOSE ASSEMBLIES 6.2 BONDING AND GROUNDING EQUIPMENT 6.3 METERS AND METERING SYSTEMS 6.4 PRESSURE GAUGE INSTALLATIONS 6.5 PAINTING AND SIGNWRITING, AIRPORT DEPOT FACILITIES 6.6 SAMPLING APPARATUS

7.0 AIRCRAFT REFUELLING EQUIPMENT


Date of Issue: June 2004 Introduction Revision Number: Original Issue Page 1

INTRODUCTION 1.0 PURPOSE

This manual provides specifications and general design guidelines for facilities and equipment to be used in handling aviation fuels. The Aviation Equipment Specifications Manual is a companion volume to the Aviation Operations and Quality Control Procedures Manuals, and has been developed to ensure that equipment used in handling aviation products meets the stringent performance requirements of ChevronTexaco Global Aviation Operations and its Quality Control Procedures.

2.0 SCOPE

This manual is intended to cover those aspects of the design of fuel handling systems which specifically apply to, or are modified by the requirements of the aviation industry, and which are not included in other ChevronTexaco or oil industry specifications for refined petroleum product handling. This introductory section outlines the application of the specifications to terminal, intermediate depot, and airport depot design. This manual contains guideline specifications for the design, installation and application of equipment and facilities for aviation product handling in fixed installations and mobile refuelling equipment.

3.0 TERMINAL DESIGN APPLICATIONS

ChevronTexaco Global Aviation quality control procedures, as they apply to terminals, require that aviation fuel handling facilities be positively segregated from other refined products, and that all facilities downstream of storage tanks shall be dedicated to one grade of aviation fuel. These requirements are essential in avoiding contamination of the aviation fuel by other products and are necessitated because generally, specification tests to detect contamination are not carried out downstream of terminal installations. Figure 1 illustrates the typical application of the aviation equipment specifications applicable to terminals. In determining the number and size of aviation fuel tanks to be installed at terminals, in addition to the normal supply and marketing considerations, the following quality control requirements must be taken into account:

a) product settling time,

b) routine tank cleaning



These restrictions on tank usage may necessitate the installation of multiple tanks in order to ensure continuity of supply, unless downstream storage is adequate to meet demand during these periods. Where refineries supply direct to airport depots, either by pipeline, tanker, barge, rail tank car or road tanker, the requirements for terminals shall apply to all facilities downstream of, and including, the distribution storage tanks.

4.0 INTERMEDIATE DEPOT APPLICATIONS

Figure 2 illustrates the typical application of the aviation equipment specifications within multi-product intermediate depots, which supply airports. The requirements for depots are generally similar to terminals, except that all facilities must be fully segregated by aviation product grade and that both incoming and outgoing product must pass through a filter separator (jet fuels) or a micronic filter (avgas).

5.0 AIRPORT DEPOT APPLICATIONS

Figure 3 illustrates the typical application of the aviation specifications applicable to airport depots. The number and size of tanks to be installed will be dependant on marketing, supply, and regulatory considerations. Generally, to ensure continuity of supply at major airports at least three tanks are necessary, i.e., one settling, one filling, and one on line for withdrawals. All facilities, pipework, etc. must be fully segregated between grades. Fuel must pass through filter separators (jet fuels) or micro-filters (avgas) both on receipt into storage and when being delivered to hydrant or refueler loading facilities.


Date of Issue: June 2004 Storage Tanks Revision Number: Original Issue CTGA 1.0 Page 1

CTGA SPECIFICATION 1.0 STORAGE TANKS 1.0 GENERAL

1.1 This specification covers the fuel tanks used in the supply chain from the refinery

to the airport destination. The general design and construction of storage tanks for refined petroleum products is adequately covered in various industry and ChevronTexaco standards. This specification therefore covers only those aspects of design and installation related to the handling of aviation fuels. This specification provides guidelines for the design, construction, installation and appurtenances to be fitted to horizontal and vertical tanks in aviation fuel service. This specification applies to tanks when they are new, opened for maintenance, or tank cleaning.

1.2 Aviation systems are designed with reliability and redundancy (2 pilots,2 engines,

2 navigation systems etc.) built into the aircraft. The fuel that is supplied to the aviation industry (since it is potentially a single point of failure) must have redundancy designed into the supply system before the fuel reaches the wingtip of the aircraft. ChevronTexacos supply chain must have rigorous quality control and have multiple redundant systems (hardware, procedures and testing) in place to make sure that the fuel meets or exceeds the customers requirements before the fuel goes in the aircraft. The CTGA customers require Clean, Dry, On-specification and Fit for purpose fuel each time they purchase aviation products.

1.3 ChevronTexaco has developed and implemented a proactive Product Integrity

Process that ensures that all of our customers get Clean, Dry and On-specification aviation fuel. ChevronTexaco has also developed and implemented policy 530 that requires our employees to systematically minimize risks of having safety and environmental incidents To this end we have adopted many best practices in our tank design. This design when implemented allows water and particulate to be easily removed from the storage tank. Each element of the design has been proven to improve product quality, safety and environmental performance. The design (when all elements are implemented together) provides the lowest risk of incidents from fire, spills, contamination, and off-specification products.

1.4 Floating suctions withdraw the cleanest product from the product surface.

Contaminants such as rust, dirt and water settle to the lowest level in the tank. The floating suction also gives an extra element of protection against a large water contamination problem. The swivel on the floating suction allows the inlet to pivot on the surface and the pontoons to keep the floating suction close to the surface at all times. An external floating suction indicator is provided to allow easy verification from ground level that the floating suction is working properly. Installing the longest floating suctions possible in our storage tanks allows the minimum settling times for our aviation products with no compromise in product quality.



1.5 Tank internal coating is provided to minimize corrosion inside the storage tank. Full coating extends the tank life, reduces the risk of premature roof replacement, bottom pitting and keeps the rust that forms in these areas from contaminating the product. Coating helps protect the environment from internal tank leaks. Internal condensation from humidity and tank hot cold cycling are to be expected. Condensation will form and cause rust and particulate in an uncoated tank and only water in a coated tank. The coating helps the water migrate to the tank low points faster. The white coating increases visibility inside the tank for visual inspections. It also makes tank cleaning faster and less costly. Properly coated tanks will last 20+ years without recoating. Once the tank is coated, particulate levels from internal tank corrosion are eliminated.

1.6 Cone roof tanks are preferred. Any floating roof tanks in aviation service should be

covered; for example a geodesic dome. Covered tanks eliminate the chance for water to enter the tank from rain, snow, and other external events. The covers eliminate the need for roof drains that have been a source of spill incidents in the past. The cover also acts as a Faraday cage that reduces the chance of a fire created by Lightning.

1.7 Sloped bottoms with deep sumps allow water and particulate to migrate to a low

point sump. The water and particulate is easily removed on a regular basis. Water and particulate must be flushed out of the tank bottom after each receipt and at least weekly

1.8 Overfill protection systems are required to prevent spills due to overfilling of the

tanks. 1.9 Inlet diffusers are provided to slow the fuel flow velocity down to less than 1

m/sec. This is required to eliminate static electricity build up inside the storage tank and to allow particulate and water to begin the settling process much more quickly.

1.10 Double bottoms or Release Prevention Barriers (RPB) are provided to enable early

detection and to prevent leaks to the ground from under the storage tank. The double bottom or RPB also extends the storage tank life and reduces risk from corrosion leaks due to bottom side corrosion.

1.11 Section 2.0 lists recommended standards for the design, construction and

installation of tanks and, in the absence of more stringent local codes or regulations, these standards shall apply.

2.0 REFERENCE PUBLICATIONS

2.1 EXTERNAL PUBLICATIONS

2.1.1 API Standard 650, Welded Steel Tanks for Oil Storage



2.1.2 Underwriters Laboratories, Inc., Standard for Steel Underground Tanks for Flammable and Combustible Liquids, U.L. 58

2.1.3 Underwriters Laboratories, Inc., Standard for Steel Aboveground Tanks for

Flammable and Combustible Liquids, U.L. 142/UL 2085 2.1.4 U.S. National Fire Protection Association, Flammable and Combustible

Liquids Code, NFPA 30 2.1.5 API Bulletin 1615, Installation of Underground Petroleum Storage Tanks

2.1.6 API Standard 2000, Venting Atmospheric and Low Pressure Storage Tanks

Non-refrigerated and Refrigerated 2.2 CHEVRONTEXACO REFERENCE SPECIFICATIONS

2.2.1 TAM-MS-967-K- Oil storage tanks of welded construction with fixed roof or open top with wind girder

http://techstds.ric100.chevrontexaco.net/tech_standards/gray/TAM/specs/tam-ms-967-k.pdf

2.2.2 TAM-MS-5018-A- Inspection of above ground storage tanks per API 653

http://techstds.ric100.chevrontexaco.net/tech_standards/gray/TAM/specs/tam-ms-5018-a.pdf

2.2.3 TAM-MS -968-K -Floating roof and internal floating roof covers for oil

storage tanks

http://techstds.ric100.chevrontexaco.net/tech_standards/gray/TAM/specs/tam-ms-968-k.pdf

2.2.4 TAM-SC-970 - Aluminum Dome Roof Installation 2.2.5 TAM-EF-887 - Tank Data Sheet 2.2.6 TAM 200- Bottom Selection and Design

http://techstds.ric100.chevrontexaco.net/tech_standards/gray/TAM/tam200__.pdf

2.2.7 TAM 800- Fire and safety design

http://techstds.ric100.chevrontexaco.net/tech_standards/gray/TAM/tam800__.pdf



3.0 TANK SIZE SELECTION 3.1 The following factors shall be considered in selecting the number and size of tanks

to be installed:

(a) the cost of tankage; (b) provision of adequate working capacity taking into account the peak period

requirements and supply replenishment pattern;

(c) product settling time and routine tank cleaning which will entail periods

when product cannot be withdrawn from a tank; (typically 3hr/ meter of product rise)

(d) Tank dead stock due to the minimum withdrawal height by floating suction; (e) Future growth trends; (f) Codes and regulations which may restrict size and type of tanks. Note: Item (c) will generally dictate the provision of at least two tanks or in the

case of horizontal tanks, one twin compartment tank. Major airport locations will require at least three tanks so that, at any one time, one can be filling, one settling and one on line for withdrawals.

3.2 Tanks have a considerable useful life (50-100yrs). Most tanks are replaced because

of size obsolescence, not mechanical failure. The incremental cost of larger tanks is small at the time of initial construction when compared to replacing an undersized tank. In aviation fuel tanks, the additional cost of lining, deflectors or diffusers, floating suctions, etc., usually makes it undesirable to commit such expenditures in small tanks.

4.0 TANK TYPES

4.1 Aviation fuels shall be stored in horizontal, above or below ground tanks or fixed

roof vertical tanks. The type to be used will generally be dictated by local regulations, location and tank capacity required. Underground tanks are suited to small airport depots and airside locations. As tank size and flow rates increase, aboveground tanks are preferred. Generally, tank sizes over 25,000 U.S. gallons should be of the vertical cone-roof type. Above ground tanks are the preferred method of storing aviation fuels.

4.2 Other considerations for the use of above or below ground storage at smaller

airport depots are as outlined below.



4.2.1 Underground tanks have the advantage of being out-of-sight, having the ground space above the tanks usable, requiring no ladders, walks, maintenance painting, dikes, generally fewer valves, have minimum breathing (minimized condensation) and can accommodate vapor recovery easily.

4.2.2 Conversely, underground tanks require burial, hold-downs if water table is

high, corrosion protection, pumps for water drains, are more difficult to clean and make leak detection difficult. It is also increasingly difficult to meet current and anticipated environmental legislation with underground tanks. Double wall underground tanks with leak detection are preferred.

4.2.3 Above ground tanks have the advantage of no surface or ground water

intrusion, simple foundations, easy leak detection, gravity waterdraws and are readily salvaged.

4.2.4 Conversely, aboveground tanks require stairs and walks, dikes, more

valves, occupy surface space, require maintenance painting and are generally less attractive for retail outlets; they are also more prone to generate water from condensation and temperature changes.

4.2.5 Semi-buried (mounded) tanks avoid the condensation problems of above

ground tanks but, in other respects, share the worst features of both underground and above ground tanks plus the problem of maintaining the covering. These tanks are not recommended

5.0 TANK CONSTRUCTION

5.1 VERTICAL TANKS

5.1.1 Vertical tanks shall be constructed in accordance with API Standard 650,

Welded Steel Tanks for Oil Storage, and shall include the features outlined below:

5.1.2 Tanks shall be covered (with either a cone-roof or dome roof, external

floating roof tanks not allowed), single slope or cone-down bottom design. The bottom slope to a sump should not be less than 1 in 30. The maximum slope (up to 1 in 15) should be used, consistent with good structural design practice.

5.1.3 Tank bottoms shall be constructed so that lap joints shall not form pockets

where dirt or water could accumulate. The Lap joints shall be placed such that they slope to the low point of the tank. Welds should be ground flush as necessary to maintain a continuous fall to the sump.

5.1.4 The sump shall be provided with a sampling line of the size and type

specified in CTGA 2.4 Fast Flush Systems for Aviation Facilities.



5.1.5 Separate product inlet and outlet nozzle connections, as well as fast flush

connection to the tank low point shall be installed. 5.1.6 Inlet diffuser pipes shall discharge near the bottom of the tank and shall be

of the low velocity type designed to minimize turbulence (refer Appendix B).

5.1.7 Floating suction in accordance with CTGA 2.3 shall be fitted to the

discharge connections on all aviation tanks. Floating suction indicators are also required

5.1.8 Tank roof hatches shall be provided to allow gauging, sampling, checking

of floating suction buoyancy and internal inspection. 5.1.9 Tanks shall be provided with at least one hinged shell manhole of at least 24

inches (600mm) in diameter, constructed in accordance with API 650, to facilitate entry for cleaning. Tanks over 20 feet diameter shall be fitted with two such manholes.

5.1.10 Pressure/Vacuum vents shall be installed on all Avgas and Jet B tanks and

free vent devices shall be installed on Jet A-1 tanks (refer to CTGA 2.2 for details).

5.1.11 All tanks shall include slotted gauge wells. Avgas tanks shall use a non

ferrous (aluminum ,stainless steel) gauge well. 5.1.12 Automatic gauging equipment shall be installed on all tanks. 5.1.13 All Airport Depot tanks shall be fully internally lined with an approved

epoxy coating in accordance with CTGA 2.5. Refinery and terminal tanks shall be coated on the bottom and sides up to the first strake (Minimum Standard); however, where they supply directly to airport depots they shall be fully lined. In situation where tank corrosion or humidity are a problem then the tanks shall be fully coated. Consideration should be given to providing a full lining for all tanks since this should be very beneficial to product quality, reduction of particulate, reduced tank maintenance, ease of cleaning, and overall tank life. Avgas Tanks shall be fully internally coated.

5.2 HORIZONTAL ABOVE GROUND TANKS

5.2.1 Horizontal aboveground tanks shall be constructed in accordance with Underwriters Laboratories, Inc. Standard U.L. 142/ 2085 for Steel Aboveground Tanks and shall include the features listed below.

5.2.2 Tanks shall be constructed not requiring any internal bracing or stiffening.



5.2.3 At least one 24 inch shell manhole shall be installed on top of all tanks. Two compartment tanks or tanks in excess of 24 feet overall length shall have two manholes fitted.

5.2.4 Tanks shall be installed on steel or concrete cradles at an angle to give a

minimum bottom slope of 1 in 30 to a sump at one end. A reinforcing plate twice the width of the cradle shall be installed at each cradle point.

5.2.5 A low point sump approximately 10 inches (250mm) in diameter and 8

inches (200mm) deep with a cone down or dished bottom shall be installed at one end of the tank. A one inch (25mm) pipe nipple shall be welded to the sump bottom at the lowest point for connection of a sample line.

5.2.6 Separate inlet and outlet connections shall be installed. 5.2.7 The inlet line shall be at the high end, positioned parallel to and on the tank

bottom, directed toward the low end sump to provide a washing action. 5.2.8 The discharge line for floating suction attachment shall be located such that

the suction is near the high end of the tank. 5.2.9 Tanks shall be built so that plate joints shall not provide pockets for

retention of water and dirt. Welding beads on the internal bottom seams protruding above the tank plate shall be ground smooth over an area extending 30 cm on either side of the center line of the tank bottom.

5.2.10 Reinforcing rings, if required, shall be installed on the outside of the tank. 5.2.11 Tanks shall be fitted with floating suction assemblies in accordance with

CTGA 2.3. 5.2.12 Tanks shall be fully lined with an epoxy coating in accordance with CTGA

2.5. 5.2.13 Normal and emergency venting shall be in accordance with API

Specification 2000 and CTGA 2.2. 5.2.14 All tanks used for Avgas/Jet B storage shall include slotted gauge wells. 5.2.15 An easily opened hatch of approximately 8 inches (200mm) diameter shall

be provided in each top manway of each tank for tank sighting. The manway skirt should be as short as possible to facilitate tank inspection through the hatch.

5.3 HORIZONTAL BELOW GROUND TANKS



5.3.1 Horizontal underground tanks may be of steel or fiberglass construction.

Steel tanks shall be constructed in accordance with Underwriters Laboratories Inc. Standard U.L. 58. Fiberglass tanks shall meet the requirements of NFPA 30 and bear the applicable U.L. label.

5.3.2 Tanks shall be installed in accordance with the requirements of API

Bulletin 1615 "Installation of Underground Petroleum Storage Tanks" and NFPA 30.

5.3.3 Tanks shall be constructed with dished convex heads not requiring any

internal bracing or stiffening. 5.3.4 At least one 24 inch (600mm) shell manhole shall be installed on the top of

all tanks. Two compartment tanks or tanks in excess of 24 feet overall length shall have two manholes fitted.

5.3.5 A low point sump approximately 10 inches in (250mm) diameter and 8

inches (200mm) deep with a cone down or dished bottom shall be installed at one end of the tank. The tank shall be installed with a minimum bottom slope to the sump of 1 in 30.

5.3.6 Separate inlet and outlet connections shall be installed. 5.3.7 The inlet line shall be at the high end, positioned parallel to and on the tank

bottom, directed toward the low end sump to provide a washing action. 5.3.8 The discharge line for floating suction attachment shall be located such that

the suction is near the high end of the tank. 5.3.9 Tanks shall be built so that plate joints shall not provide pockets for

retention of water and dirt. Welding beads on the internal bottom seams protruding above the tank plate shall be ground smooth over an area extending 30 cm on either side of the center line of the tank bottom.

5.3.10 Reinforcing rings, if required, shall be installed on the outside of the tank. 5.3.11 Tanks shall be fitted with floating suction assemblies in accordance with

CTGA 2.3. Steel tanks shall be fully lined with an epoxy coating in accordance with CTGA 2.5

5.3.12 Normal and emergency venting shall be in accordance with API

Specification 2000 and CTGA 2.2. 5.3.13 All tanks used for Avgas/Jet B storage shall include slotted gauge wells. 5.3.14 An easily opened hatch of approximately 8 inches (200mm) diameter shall

be provided in each top manway of each tank, for tank sighting. The



manway skirt should be as short as possible to facilitate tank inspection through the hatch.

5.3.15 A one inch (25mm) nominal bore stainless steel sample line shall be

installed in the tank sump approximately one inch (25mm) above the sump floor and extend to a pipe flange on the tank top. A semi-rotary or diaphragm pump shall be installed above ground level for drawing sump samples.

5.3.16 All buried steel tanks shall be coated externally with a suitable protective

coating system. The primary function of a coating system is to establish a permanent barrier

between the tank and its environment. The more common protective coatings for buried tanks are coal tar enamels,

hot applied mastics and cold applied mastics. Experience has shown that coal tar coatings meet the requirements for most environments normally encountered.

The ability of a coating to perform is a function of application, chemical,

electrical and physical properties; accordingly a coating should have:

(a) Good dielectric strength to assure high electrical resistance; (b) Resistance to moisture absorption; (c) Resistance to water vapor transmission;

(d) The ability to withstand physical damage from impact and abrasion

during installation; (e) The ability to resist deformation from soil stresses generated during

expansion and contraction of soil; (f) Ease of application; (g) Resistance to environmental contaminants; (h) Strong and permanent adhesion to the tank surface.

The coating shall be compatible with the alkaline environment associated with cathodic protection.

Several protective coatings have been formulated, each of which may not

exhibit all of the desired properties required for optimum service in a specific environment. To assist in the evaluation of coating materials, standardized procedures have been provided by ASTM and NACE which



provide criteria for qualifying coating material. All factors that influence the effectiveness and performance of a coating shall be evaluated fully before making a final decision.

6.0 STAIRS, LADDERS AND WALKWAYS

6.1 Access to the tops of tanks may be provided by circular stairs, straight stairs and ladders, or crosswalks from existing tanks. Where distances and the types of tanks permit, a crosswalk from one tank to the other is the preferred means of access. Construction details shall conform to Safety In Design requirements. See attached link.

http://techstds.ric100.chevrontexaco.net/Tech_standards/Specialt/Sid/TOCfwrd.pdf

Note: There must be at least two sets of stairs (one on each end tank) when two or

more tanks are connected by crosswalks.

6.2 Stair treads shall be of steel grating or proprietary tread-safe plate. Design and construction shall be in accordance with standard practice.

6.3 Railings must be provided wherever it is necessary for people to walk on tanks in

the course of ordinary operation. 7.0 TANK LOCATION AND SPACING

The location of tanks with relation to other tanks, buildings, property lines, etc. shall be in accordance with NFPA 30 or local regulations, whichever are more stringent.

8.0 CONTROL SPILLAGE

Dikes for retention of spillage from tanks shall be in accordance with the requirements of NFPA 30 or local regulations, whichever are more stringent.

9.0 TANK CALIBRATION

All tanks shall be calibrated in accordance with API Standard MPMS (Manual of Petroleum Measurement Standard) 2.2A (tank strapping method) or 2.2B (optical reference line method).

10.0 SUB-SURFACE FOAM INJECTION

10.1 Foam injection system, where required, shall comply with current ChevronTexaco standards and any local statutory regulations.



10.2 No galvanized pipework shall be permitted downstream of the check valve; such

pipework shall be lined internally with an approved epoxy coating in accordance with CTGA 2.5.

10.3 A test point is required between the Rupture Disk and non-return valve (NRV) to

permit periodic checks to ensure that there is no fuel passing the NRV and no water or foam passing the rupture disk.

10.4 The spectacle blind or other positive isolation (twin seal valve) is necessary to

ensure there will be no contamination of product during testing; a gate valve at the tank shell is not adequate for this purpose.



APPENDIX A TANKS FOR HAZARDOUS PRODUCTS (JET B AND AVGAS) At normal storage temperatures, certain products will emit vapors to create an air-vapor mixture in the tank vapor space that can be in the explosive range. Products generally in this classification have a flash point of 100oF (38oC) and less and a Reid vapor pressure of 4.5 psi and less; Jet B falls within this category. Products having a flash point above 100oF (38oC) and Reid vapor pressure of less than 4.5 psi are normally handled at temperatures well below their flash point where the vapors emitted are too lean to ignite. Jet A and Jet A-1 fall within this category. Products having a flash point below 100oF (38oC) and a Reid vapor pressure of above 4.5 psi, such as aviation gasolines generally emit vapors too rich to ignite. In the event of any question regarding any product, ChevronTexaco Global Aviation Operations is to be consulted. If an explosive mixture in the tank vapor space should ignite, a violent explosion would result. The chief source of ignition is static electricity. Agitation of product in a tank generates an electrostatic charge which accumulates on the surface of the product. Depending on the conductivity of the product and the degree of agitation, the surface charge can bleed off to the tank shell as fast as it is generated. Under some conditions, however, the charge can build up faster than it can bleed off and, when the potential becomes sufficient, a spark will jump from the surface of the product to the metal of the tank. Conditions are frequently at a critical point where a spark will jump to a hand gauge tape, thieving device or any other object admitted into the vapor space. Such sparks can be of sufficient intensity to ignite an explosive vapor mixture. Avgas/Jet B can be handled with safety by (1) eliminating tank vapor space and (2) eliminating all sources of ignition. In addition, a safety measure to be strictly enforced is that no person is to be permitted on a tank containing a hazardous product until filling or withdrawal of product has been stopped and product is quiescent (at least 30 minutes). Tanks with internal Floating roofs are to be used generally for Avgas/Jet B. Internal floating roofs shall be double deck or annular pontoon roofs (see Appendix D) Standard vertical tanks with cone roofs and horizontal tanks may be used but each instance must have approval from Aviation Operations and each tank must be equipped with the appurtenances discussed below.



Appurtenances for tanks with hazardous products Each tank used for Avgas/Jet B must have the following equipment: Inlet Nozzle Diffuser: To minimize agitation, the velocity of product entering the tank must be limited to 3 feet per second or less. This may be accomplished by properly sizing the tank inlet nozzle but it is generally more economical to install a diffuser funnel as shown in Appendix B. Tank Vents: Air admitted into a tank through the inlet nozzle, in advance of or with the incoming product, will bubble up through the product and generate an electrostatic charge. Normal operations will generally not require use of air eliminators but, if conditions prevail that admit amounts of air into the system, a properly sized air eliminator is to be installed. Automatic Tank Gauge: Each tank is to be equipped with an automatic tank gauge to minimize the need for hand gauging. Slotted Gauge Well: Facilities for hand gauging or thieving from the top of tanks shall include (non- ferrous aluminum/stainless steel for Avgas) slotted gauge wells. Thermal Relief: No piping is to be permitted that will form an "overshot line" (permit product to fall freely from top of tank to liquid surface). A thermal relief line that discharges into the shell nozzle is the only type that will be used. See Appendix F. Tank Stairs and Crosswalks: Access to the tops of tanks used for hazardous products should be limited to the minimum needed for periodic inspection of breather valves and other appurtenances. To the degree practical, stairs and crosswalks for adjacent tanks for other products should be arranged in such a manner that the operator does not have to go onto or across the tanks used for hazardous products. Internal floating roof or Pressure safety vacuum fittings- this will control the vapors from leaving the tank. Floating suction and floating suction indicator Deep sump Sloped bottom to tank low point.



APPENDIX B INLET NOZZLE DIFFUSER FOR JET FUEL AND AVGAS



APPENDIX C - Jet Tank Design Vertical Tanks



APPENDIX C - Jet Tank Design Vertical Tanks (Continued)



APPENDIX D AVGAS- Tank Design - Vertical tanks -External floating roof with dome



APPENDIX D AVGAS- Tank Design - Vertical tanks-Cone roof with internal floating roof



APPENDIX D AVGAS- Tank Design - Vertical tanks- Nozzle orientation



APPENDIX D AVGAS-small tank design Vertical



APPENDIX E - Avgas Internal Floating roof



APPENDIX F - Thermal relief for tanks


Date of Issue: June 2004 Table of Contents Revision Number: Original Issue Section 2 Page 1

SECTION 2 TABLE OF CONTENTS

2.0 TANK APPURTENANCES 2.1 VALVES 2.2 TANK VENTS 2.3 TANK FLOATING SUCTIONS 2.4 FAST FLUSH FACILITIES 2.5 INTERNAL COATINGS


Date of Issue: June 2004 Selection of Valves Revision Number: Original Issue CTGA 2.1 Page 1

CTGA SPECIFICATION 2.1 SELECTION OF VALVES 1.0 GENERAL

1.1 This specification provides guidelines for the selection of valves in aviation service fuelling systems.

1.2 All valves used shall comply with the requirements of the relevant API

Specification.

1.3 The class of valves used by ChevronTexaco in their aviation fuelling systems and equipment are generally (a) class 150 which have a maximum working pressure rating of 275 psi and (b) class 300 which have a maximum working pressure rating of 720 psi. The class designations are the same rating designations for ANSI B16.5. Class 600 valves, under special circumstances, may be used underground in hydrant systems.

1.4 Hardened 12% chromium steel is the most widely available and acceptable material

for stems, seats and discs and should be specified when ordering valves.

1.5 Packing material should be compatible with the service of aviation fuel. Teflon packing should not be used because it is not fire resistant; however, in some applications, Teflon may be used as a valve seat for soft seat valves.

1.6 Valve seals and O rings should either be of Viton A or Buna N.

1.7 Bronze or brass material shall not be used for sleeves, drive nuts, sleeve nuts and

gland followers.

1.8 Reference should be made to manufacturers recommended practice when overhauling valves.


API STD. 599 Steel and Ductile Iron Plug Valves API STD. 600 Steel Gate Valves API STD. 609 Butterfly Valves API SPEC. 6D Pipeline Valves ANSI/ASME B-16.5 - Pipe Flanges and Flanged Fittings

3.0 TYPES OF VALVES



There are many types of valves in common use. The general use and broad description of various types of valves used by ChevronTexaco in its aviation fuel systems and equipment are discussed below.

3.1 GATE VALVES Gate valves are available as rising stem or non-rising stem. Only rising stem cast

steel body gate valves with an outside screw and yoke (OS&Y) are to be used in aviation service. These valves have the advantage of being self-indicating as the stem, when the valve is open, projects above the stationary hand-wheel and one can readily see whether the valve is open or closed. Further, the design isolates the thread from the fluid, reducing galling and thread corrosion. Non-rising stem gate valves are not self-indicating and should not be used.

Gate valves are preferred for open and shut applications. The valves, however, are

more prone to leak than other shut-off type valves. They are not suitable for throttling service. Gate valves offer considerably lower resistance to flow than other type valves and are preferred for general use because of their low-pressure drop characteristics, general ruggedness and simplicity.

Steel valves shall be used on storage tanks and where the valve location is exposed

to mechanical hazards.

3.2 BUTTERFLY VALVES Butterfly valves are economically attractive in flanged piping compared to gate

valves. Wafer-type butterfly valves which have only a short cylindrical body with no separate flange ends are normally installed between two (2) piping flanges. Wafer-type butterfly valves have been extensively used in dispensing equipment and experience with these valves has been most satisfactory in spite of their limitations which include: (a) overbolting can be a problem on butterfly valves which have an elastomer

liner extending over both faces and the body to act as both gasket and seat. If overbolted or subject to line movement, the liner can bulge into the valve cavity, making the valve disc difficult or impossible to operate;

(b) leakage can be caused if the flanges become misaligned.

3.3 DOUBLE BLOCK AND BLEED VALVES These valves are used where effective, positive product isolation is required. Most

of these valves make use of elastomer seals backing up the metal-to-metal seal on both faces of the gate.

The block and bleed valve provides an upstream seal, downstream seal and a bleed

point between them thus it can replace the typical Jack Spool arrangement of two (2) valves plus a removable spool piece and a drain. When the valve is closed, the



sealing segments are wedged tightly between plug and body bore, metal-to-metal. The resilient seal material is compressed safely into a recessed groove. The bleed should be automatic in all aviation applications to eliminate the possibility of human error in forgetting to open (and close) the bleed; automatic operations also prevents thermal pressure from building up and damaging seals. However, given that a bleed can block, there should be a visual or electronic alerting system for pressure build up which may be caused by a valve leak. Some valve manufacturers may also require a thermal pressure relief valve in the valve body to protect valve seals.

Note: Environmental considerations will usually require some form of collection

system for any product lost from the bleed.

3.4 GLOBE VALVES These valves are primarily used for throttling or flow control service.

3.5 LUBRICATED PLUG VALVES These valves are used in rapid open and shut operations. Although these valves

provide a more positive shut-off than gate valves, they are not recommended for aviation fuel service, since the lubricant required for their effective operation may contaminate the fuel. Where tightness is essential and lubricated plug valves must be installed temporarily, an approved non-soluble (in aviation fuel) lubricant should be used and applied sparingly.

3.6 BALL VALVES These valves are used in open and shut applications. These valves are easy to

operate and are preferred when rapid operation is desirable. They are not to be used for throttling because of potential stem leakage.


Date of Issue: June 2004 Tank Vents Revision Number: Original Issue CTGA 2.2 Page 1

CTGA SPECIFICATION 2.2 TANK VENTS 1.0 GENERAL

1.1 This specification provides guidelines for selection and installation of venting devices for aviation fuel storage tanks.

1.2 Storage tanks must be fitted with adequate venting devices to protect the tank from

excess pressure and vacuum buildup under the following conditions:

(a) inbreathing due to outflow of product from the tank, atmospheric temperature decreases and rapid cooling of the tank air space due to rain showers;

(b) outbreathing due to both inflow of product to the tank and atmospheric

temperature increases; (c) outbreathing due to fire exposure (emergency venting).


2.1 API Standard 2000, Venting Atmospheric and Low Pressure Storage Tanks. 2.2 API Standard 650, Welded Steel Tank for Oil Storage. 2.3 NFPA 30, Flammable and Combustible Liquids Code.

3.0 VENT CAPACITY

3.1 API Standard 2000 Venting of Atmospheric and Low Pressure Storage Tanks shall be used as the minimum standard for calculating required normal and emergency venting capacity. API 2000 Section 1 covers the following: (a) determination of venting requirements; (b) normal venting capacity requirements:

inbreathing outbreathing, (c) emergency venting capacity requirements;



(d) means of venting: normal vents, emergency vents, vent discharge and

(e) testing of venting devices.

3.2 Vent manufacturers data sheets should be consulted to choose vent devices matching the required capacity calculated in accordance with API 2000; however in no case should vents or vent lines be smaller than three inches (3) (150mm).

4.0 NORMAL VENTING

4.1 Pressure/Vacuum vents shall be used for Jet B and Avgas storage tanks. Free vent devices are preferred for Jet A-1 tanks.

Note: Free vents should be used for Jet A-1 for quality control reasons; free vents

allow water which may be coming out of solution to go to the atmosphere rather than accumulate in the tank.

4.2 Pressure/Vacuum (P/V) Vents: The prime purpose of P/V vents is conservation of

product. By keeping volatile products under pressure, evaporation losses are reduced. The pressure which may be applied to the product will depend on tank design. Small tanks can generally withstand higher internal pressures than large tanks. Conversely, smaller tanks with unsupported cone roofs can withstand less vacuum than large tanks with roofs supported on rafters.

4.3 Recommended pressure settings to allow the pallets to start to open are as follows:

PRESSURE VACUUM SMALL TANKS (Under 1.75 oz./sq. in. oz./sq. in. 16 feet Diameter) (3 water) (.865 water) LARGE TANKS (16 feet oz./sq. in. 7/8 oz./sq. in. Diameter and Over) (.865 water) (1- water)

4.4 The above denotes the actual total loading in psi (including weight of pallet)

desired and it is intended the pallets start to open when internal tank pressures reach these values. The pressure at which a pallet will be wide open will vary from one and one-half to two (1 to 2) times the pressure setting depending on the make and design of the valve. Due to the different operating characteristics of the different makes and types of valves, it is therefore necessary that the manufacturers determine the actual weight or loading to be placed on the pallets to comply.



4.5 Free Vents: The simplest form of free vent comprises a U-shaped pipe section

inverted with a wire screen to exclude insects, etc. Proprietary free vents with rain hoods and gauze screens are available for larger vertical tanks. Adequate attention must be given to exclusion of rain water from the tank. The wire screen should have four (4) holes per inch.

4.6 Vent Filters: Due to the quality requirements to minimize the amount of

particulate matter entering aviation tanks, filters may be required on vents. Cartridge air filters have been installed successfully in locally prefabricated housings. On smaller tanks, large automotive air filters have also proved to be successful. Care must be taken in selecting filters to ensure that the breathing capacity in CFM is compatible with the breathing capacity with the vent used, assuming negligible differential pressure across the filter. If not inherent in the design of the filter, emergency relief should be provided to safeguard against filter blockage causing excessive pressure or vacuum in the tank.

5.0 EMERGENCY VENTING

5.1 API Standard 650 for new welded tanks specifies details of a weak roof attachment for cone roof tanks which is intended to fail preferentially to any other joint and relieve any excessive internal pressure.

5.2 All other above ground tanks shall be fitted with emergency vents. An economical

means of providing emergency venting is the installation of emergency vent manhole covers. These are available to fit standard API 20 inch and 24 inch roof manholes and are adjustable to relieve pressure from approximately 0.6 oz./sq.in. to 6.0 ozs./sq.in. Preferably, they should be set at oz./sq.in. above the normal vent pressure setting. In the case of freely vented tanks the lowest pressure setting available shall be used. Other emergency vents available include hinged hatches which are spring loaded to open and held in the closed position by a light pin which shears in an over-pressure condition. Others are held closed by magnetic latches.

6.0 VENT DISCHARGE

6.1 Vent discharge pipes for underground tanks shall be sized, located and arranged in accordance with NFPA 30.


Date of Issue: June 2004 Tank Floating Suctions Revision Number: Original Issue CTGA 2.3 Page 1

CTGA SPECIFICATION 2.3 TANK FLOATING SUCTIONS 1.0 GENERAL DESCRIPTION

1.1 This specification provides guidelines for selection and installation of Floating Suctions for use in aviation fuel storage tanks.

1.2 Floating suction assemblies basically consist of a hinged suction arm suspended

from floats so that withdrawal is made from near the top surface of product, thereby reducing the possibility of contamination of the fuel by water and particulate matter. A mechanical stop is provided to limit downward travel of the suction arm so that any sediment or water on the tank floor cannot be drawn into the suction line.

1.3 Twin floating suctions are sometimes used when flow rate from older tanks needs

to be increased; twin suctions can be inserted into the tank via existing manways whereas a larger single suction may be too big.

2.0 REQUIREMENT

2.1 Floating suctions shall be installed on all aviation fuel storage tanks at airport depots and at refineries and terminals which supply directly to airport depots. The use of floating suctions is highly desirable on all tanks in aviation fuel service.

3.0 GENERAL DESIGN FEATURES

3.1 Floating suctions are available as complete assemblies from approved suppliers. When specifying floating suctions, the following design features should be included:

(a) floats should be of aluminum or stainless steel and shall be injection filled

with urethane foam. Floats shall be pressure tested after sealing; (b) suction pipe shall be aluminum or fully epoxy coated carbon steel. Epoxy

coatings shall conform to MIL. SPEC. C-4556E latest issue; (c) swivel joints shall be double row ball bearing type incorporating twin

VITON seals. The ball races shall be permanently pre-lubricated with a grease which is not soluble in aviation fuel and which shall be retained between the seals to prevent contamination of the fuel. Teflon lubricant is preferred;

(d) the suction nozzle shall be of a conical, bellmouth design to reduce inlet

velocity and shall incorporate an anti-vortex plate. The nozzle shall be connected to the suction arm with a 90 downward facing elbow;



(e) Appendices A & B illustrate the preferred suction installation for vertical

and horizontal tanks; (f) a rest shall be installed in order to limit downward travel of the arm and

break suction at a specified height above the floor level of the tank. The rest may consist of a U-shaped foot attached to the suction bellmouth or a tubular steel support arch, welded to the tank floor. The height of the suction break point should be approximately 9 inches (225mm) above the tank floor for horizontal tanks, and 18 inches (450mm) above the tank floor for vertical tanks and design should be such that the suction arm is close to horizontal in the rest position with a slight fall towards the nozzle.

4.0 FLOTATION INDICATOR

4.1 Each floating suction shall be fitted with a means to check buoyancy. 4.2 The simplest method is the connection of a stainless steel check cable between the

floating arm and a roof top hatch. The drawbacks with this system are that to check buoyancy a hatch must be opened with the possibility of contamination entering the tank and there is the possibility of the slack check cable becoming snagged on the suction arm or floats thus restricting downward travel of the arm. The latter can be overcome by running the cable through a pulley block at the hatch and suspending a weight from the free end to maintain a light tension on the cable.

4.3 The preferred method for vertical tanks is to specify an external indicator. These

are commercially available for small tank installations and can be fabricated for larger tanks using cable drive accessories designed for automatic tank gauging.

4.4 Indicators for floating suctions installed under floating pans, shall be of the external

indicating type. The indicator cable shall be attached to the suction arm close to the swivel to minimize lateral movement of the cable. The cable shall pass through a seal plate in the floating pan of the type used for anti-rotational cables. The indicator cable must be externally weighted or spring retained so as to be under slight tension at all times.

5.0 BONDING

5.1 All parts of floating suctions shall be bonded together and to the tank shell such that electrical resistance between any part of the assembly and the tank shell shall not exceed 10,000 ohms. Particular attention should be paid to flotation indicator cables and to floats which may come into contact with the tank roof or floating pan.

6.0 THEORETICAL HEAD LOSS



6.1 The theoretical suction head loss for floating suctions will depend on the product type, size of the bellmouth, size and length of suction arm pipework and number and type of swivels. Potential suppliers should be requested to supply head loss data. The total head loss from bellmouth through to tank nozzle should be limited to two feet (2) of product at system design flow rate.



FLOATING SUCTIONS FOR HORIZONTAL ABOVE & BELOW GROUND TANKS

Legend Key No. Description 1 Bellmouth and Baffle 2 Float, Stainless Steel 3 Flanged Swing Joint 4 Vertical Drop Tube 5 Inspection Cable


Date of Issue: June 2004 Fast-Flush Facilities Revision Number: Original Issue CTGA 2.4 Page 1

CTGA SPECIFICATION 2.4 FAST FLUSH FACILITIES 1.0 GENERAL

1.1 Aviation tanks are considered in critical service and must maintain a high quality of product in order to meet stringent safety requirements prior to fuel loading on the aircraft. Contaminated fuel, water and particulate must not be allowed to progress downstream from each storage tank in the supply chain and reach the aircraft! Although procedures are in place that provide for proper filtration and product sampling prior to aircraft fueling, the accumulation of a sludge/sediment/water layer on the tank bottom can compromise the integrity of the product and, potentially, the downstream filtration systems. First, tank integrity is affected due to the corrosive nature of the water/sludge material. Second, downstream filtration efficiency can be affected by the potential transfer of the layer of corrosive products, water, solids and microorganisms.

Implementing a proper water draw program greatly reduces the likelihood of this contamination. Under most circumstances, water, and particulate can be removed through the water draw-off sump valve. This procedure works well as long as the sump is located at the lowest level of the tank bottom and the water draw equipment operates properly. Another critical element of the process is to rigorously follow the water draw procedures (frequency, duration) and have well trained personnel. Bottom sediment and water that cannot be removed from the sump during normal water draw-offs must be removed during regular cleaning cycles with the tank out of service This specification details the guidelines for construction and installation of fast-flush sampling systems on vertical above ground tanks used for storing aviation fuel.

1.2 Fast-flush sampling systems shall be installed on large vertical storage tanks to

enable bottom samples to be drawn from the tank in sufficient quantity and at sufficient velocity to flush the maximum amount of water and particulate matter from the tank floor and to concentrate these contaminants in a receiving vessel for examination and disposal. Fast-flush systems also allow the complete draining of tank bottom water without any loss of product. The system basically consists of sampling pipework leading from the centre sump of a cone down tank bottom or other low points within a storage tank to an appropriately sized receiving vessel where the samples can be examined and contaminated product subsequently withdrawn. A return pump and line are provided to return clean product to the storage tank inlet.

1.3 Appendix A illustrates typical installation of fast-flush system.



2.0 REQUIREMENT

2.1 Fast-flush facilities are not required on small vertical storage tanks which meet all of the following criteria:

(a) capacity less than 30,000 USG (113,500/litres); (b) diameter less than 20 feet (six (6) meters); (c) cone roof, cone down bottom with a floor slope to the water drawoff sump

of at least one (1) in 30;

(d) fully lined internally with an approved epoxy coating;

however, an effective sampling connection to the sump is required.

2.2 All other vertical storage tanks shall have fast-flush facilities installed. 2.3 Fast-flush facilities are not required for horizontal tanks. If they meet all of the

following conditions:

(a) They are sloped to a low point drain (b) The tank is fully internally epoxy lined (c) An effective sampling connection to the sump is required. The sampling line

needs to be at least 1 (25 mm) diameter. The sampling line needs to be installed coming from the bottom of the sump reservoir.

3.0 RECEIVING VESSEL SIZE SELECTION

3.1 The basic size of sample receiving vessel (fast-flush tank) shall be 200 litres. This size is sufficient for airport tanks up to 5,000 barrels capacity with a bottom slope to the sampling point of at least one (1) in 30 and which are supplied via a filter separator.

3.2 The chart below is a guide for sizing fast-flush tanks for different sized and shaped

terminal storage tanks supplied by other methods. The multiplication factors may be used to calculate the recommended size of fast-flush tank. 200 litres is usually sufficient for an airport tank of any size.

CRITERIA CONDITION FACTOR

Tank Capacity 800-5,000 bbl. :X1

5,000-20,000 bbl. :X1.5 Over 20,000 bbl. :X2



CRITERIA CONDITION FACTOR Supply Method Dedicated Pipeline with Filter Separator :X1

Dedicated Pipeline, Unfiltered :X1.5 Marine Delivery, Dedicated Pipeline :X3 Marine Delivery, White Products Line :X4

Marine Delivery, White Products Line (water interface) :X6

Refinery Run-Down Tank :X3

Bottom Slope To 1 in 30 or Greater :X1 Main Tank Sample Point:- 1 in 30 to 1 in 60 :X1.5

Less Than 1 in 60 :X2.0 3.3 Example: A 25,000 bbl. storage tank with a flat bottom supplied by marine

transport through a dedicated Jet A-1 line: Basic X tank size factor X supply factor X floor factor 200 X 2 X 3 X 2 = 2,400 litre fast-flush tank required 3.4 The above is only a guide. Local experience may indicate that fast-flush tanks

should be larger or smaller. For example, at airport depots where experience has shown that very little water or sediment is present in tank sumps, 200 litres is nearly always sufficient regardless of tank size. Conversely, at marine terminals where water interfaces are taken into the tanks, larger flush tanks may be required.

3.5 When retrofitting fast-flush systems on flat bottom tanks in service, the tank floor

must be checked and, where more than one low point is evident, sample lines should be installed at each of these points. In such cases, it may be more practical to install two (2) fast-flush tanks of smaller size, being supplied from separate low points.

4.0 SAMPLE LINE

4.1 The sample line shall extend from a central point in the storage tank sump

approximately one (1) pipe diameter above the sump floor, through the tank wall, via an isolation gate valve and throttling ball valve to the fast-flush tank. Where possible, the sample line should be continuously sloped towards the sample tank to improve drainage.

4.2 The sample line shall enter the flush tank on the side immediately above the V-

cone bottom, and terminate in an elbow angled to direct the product stream around the vessel wall and slightly downwards in order to create a swirl and concentrate the heavier contaminants in the central sump of the vessel.



4.3 Sample lines to fast-flush tank systems shall be stainless steel or internally epoxy coated carbon steel.

4.4 Recommended nominal internal diameters of sample lines shall be as follows: Fast-Flush Tank Size Pipe Diameter 200-2,000/litres 2 (50mm) Above 2,000/litres 3 (75mm) 4.5 It is essential that the sample line is of constant diameter from the main tank sump

to the fast flush inlet; otherwise, although there may be an impressive velocity and swirl at the fast flush tank inlet, movement of product in the sump will be sluggish and not pick up much water or sediment.

5.0 SAMPLE TANK CONSTRUCTION

5.1 Sampling tanks shall be constructed in accordance with the requirements of CTGA 1 and feature a cone down bottom with a slope towards the center sump of at least one (1) in 30; much steeper angles (as much as 45 degrees) are preferred.

5.2 Tanks shall be fully internally lined with an approved epoxy coating or constructed

of aluminum or stainless steel.

5.3 The following tank appurtenances shall be fitted:

(a) a visual level indicator / sight glass tube; (b) a hinged roof manway for access to inspect and clean the tank. On smaller

tanks the complete top cover should be removable. All tanks should be easy to inspect; those with very heavy or bolted down covers should include an eight inch (8) inspection hatch in the lid;

(c) A stainless steel drain line of one inch (1) (25mm) diameter from the tank

center sump, terminating in a spring loaded ball valve (Apollo Type), which acts as a deadman, and cap (there must be sufficient space below the drain valve to allow placing a five (5) gallon pail under it for drawing samples);

(d) a sample point for obtaining running samples from the fast-flush line;

(e) a return line from the lowest point in the tank. 6.0 PRODUCT RETURN PUMP

6.1 An electric or air-driven product pump shall be installed to return clean, sampled

product to the storage tank inlet line. The pump should be of sufficient capacity to enable return of the complete contents of the sampling tank within approximately 10 minutes.



6.2 On larger fast-flush systems, there may not always be sufficient storage tank head

pressure to create a high velocity sample rate or the product level may sometimes be below the sample tank height and gravity sampling cannot be used. In these cases, the return pump should be installed with pipework allowing it to also be used to pump product from the storage tank sump into the fast-flush tank.

7.0 RETURN LINE

7.1 Clean product must not be returned to storage via the sample line. It should be

returned to the storage tank inlet line or a separate tank inlet installed for this purpose.

7.2 A check valve shall be installed in the return line. 7.3 Isolation blind shall be installed in the supply and return lines. This will allow

proper isolation of equipment prior to performing maintenance work.

8.0 RETURN FILTER MONITOR 8.1 A filter monitor should be installed in the return line to prevent any water or

particulates from re-entering the storage tanks.

9.0 WATER AND OTHER CONTAMINANTS

9.1 Water and other containments must be drained to the oily water separator and discharged in an approved manner acceptable with local and company regulations.

10.0 TIMING FOR IMPLEMENTATION

10.1 Timing for compliance should be within the next aviation inspection cycle. If a facility does not currently have a fast flush system or does not qualify for the exemptions currently outlined in this document then the operator needs to propose an installation time frame to CTGA Manager of Product Quality and Manager of Airport Operations to gain agreement on the installation date of the fast flush system.

11.0 EXEMPTIONS

11.1 Exemptions need to be requested in writing and need to follow a documented Management of Change process. Exemptions can only be approved by the Manager of Product Quality and Manager of Airport Operations.



APPENDIX A


Date of Issue: June 2004 Internal Coatings Revision Number: Original Issue CTGA 2.5 Page 1

CTGA SPECIFICATION 2.5 INTERNAL COATINGS 1.0 GENERAL

1.1 This specification outlines the requirements for selection, surface preparation and application of internal coatings for tanks, pipelines and ancillary equipment in aviation fuel service.

1.2 Internal corrosion makes the use of unlined carbon steel pipes and tanks

unsatisfactory for storage and transportation of aviation gasolines, turbine fuels or water/methanol mixtures. Corrosion inside a tank or along the walls of a pipeline is caused by the action of moisture suspended in the fuels being stored or transported.

Since there is the danger of discolouration and contamination of the product due to

particulate matter formed from metal corrosion, organic epoxy coatings shall be applied. These coatings prevent steel from corroding and consequently contamination of product.

1.3 However, unlined transportation pipelines of "pickled" black steel may have

benefits provided they are expected to be used frequently (at least every two days) and with product velocity of at least 7 feet per second (2.1 metres per second). Benefits include substantially lower initial cost and no concerns with lining deterioration. Experience has shown that such lines do not generate excessive particulate matter.

1.4 The following information should be reviewed with potential suppliers and

contractors prior to commencement of work.

1.5 Regardless of the coating (or use of pickled black steel), thorough flushing of the line is required as part of the commissioning process (refer CTGA 3.1).


2.1 Steel Structures Painting Council Surface Preparation Specifications (SSPC No. 5) 2.2 U.S. Military Specification MIL-C-4556E (or later issue) and its associated

Qualified Products List.

3.0 SURFACE PREPARATION

3.1 Proper surface preparation is essential to a successful, long lasting coating job. This requires abrasive blasting to white metal. The surface to which the organic

epoxy coating is to be applied shall not be less than Steel Structures Painting Counsel Specification SSPC No. 5 (white metal blast). The anchor pattern shall be as called for by the coating manufacturer or approximately 20% of the final dry



film thickness of the coating system. Anything less than this could lead to early coating failure.

3.2 Alternate specifications for blasting to white metal are U.S. National Association of

Corrosion Engineers NACE No. 1 or British Standard BS 7079. 3.3 Pickled steel requires especially careful preparation; therefore full material

specifications are essential in determining procedures to be followed. Commercial pickling is sometimes used to facilitate forming prior to fabrication and to remove mill scale. Often times this process leaves a contaminant of sulfates on the steel and, unless careful blasting to white metal is done, some contaminants could remain and ruin the coating application. A check should be made after blasting to see if any contamination remains.

3.4 After blasting, all surfaces shall be cleared of foreign material and blown free of

dust before coating. After coating solvent in pipes or tanks has evaporated from the applied area, end caps shall be fitted on to pipes and manholes on tanks in order to keep out dust and dirt.

4.0 CAUSES OF FAILURES

4.1 Often, a contractor will use local sand because of the expense or time involved in obtaining proper abrasives which have to be shipped into the area. Some contractors may try to use common river bottom type sand that does not have the correct sharpness and may contain clay inclusions. Another common error is to reuse abrasive material when a contaminated surface is blasted. The surface may appear clean; however, under microscopic examination small inclusions will be detected which will not allow proper bonding of the coating. Timing is also critical. Steel begins to corrode as soon as it is exposed to air. Therefore specified times between completion of blasting of each piece of a surface and application of the first coat of paint to that surface must observed.

4.2 Air pressure of 80 psi or less will not produce proper patterns on the steel. When a

pitted surface is to be coated, unless the blast hits pits from all angles, the corrosion will remain causing subsequent blistering of the coating. Many surfaces can be contaminated after proper blasting by foreign material - even a fingerprint, for example. The fingerprint will not be noticed until the coating has been applied and seen service. Coating failures can also be caused after application by improper cleaning of the surface such as the application of a solvent to which the organic epoxy coating is not resistant. Finally, most coating failures are caused by improper application of the materials, use of the wrong primer, improper dilution for spraying, use of wrong spray technique or excessive time between blasting and coating. Contractors experienced in this type of coating application should be used.

5.0 COATING SPECIFICATIONS

5.1 Internal coatings shall be shop or field applied and should be of a generic type consisting of a two (2) component glossy amine (organic) cured epoxy resin



coating system. The coating system should be of the bisphenol type, comprising a pigment primer and finish coat of contrasting colours and shall meet the requirements of U.S. Military Specification MIL-C-4556E (or later issue). Other coatings may be approved refer paragraph 7.0. The welding burnback area for the recommended API grade 5L pipe with beveled ends shall be approximately one inch (1) from ends with any coating used.

6.0 APPLICATION

6.1 Coatings shall be applied in accordance with the manufacturers specifications. Important general criteria to note are:

(a) time between sand blasting and application of prime coat must be limited to

avoid the possibility of rust bloom forming. In tank lining, only that area which can be coated in one (1) working day shall be sand blasted;

(b) most coating systems specify a maximum interval between application of

the prime and top coats to ensure a good bond; (c) sufficient air curing time must be allowed before the tank or pipe is placed

in service; (d) after the initial fill of a lined tank, the commissioning product should be

quarantined and remain dormant for five (5) days after which product samples should be drawn and subjected to a recertification test to ensure that no contamination has occurred from the coating. If these tests are satisfactory the product may be released and the tank placed in normal service.

7.0 APPROVED COATINGS

7.1 All coating systems included in the Qualified Products List attached to U.S. Military Specification MIL-C-4556E (or later issue), (included in Volume II of this manual) are approved for use. Selection of the approved system to use shall be based on field experience, local availability and economy.

7.2 Coatings additional to those in the QPL may be approved from time to time by

ChevronTexaco Aviation Operations. Those currently approved are included in Appendix A. Factors influencing choice of supplier include: - local availability and price, - local technical back up and - local conditions (some systems are easier to manage than others in very hot

conditions).



8.0 COATING DATA The following data under the heading Internal Coating shall be signwritten on the tank in

letters 25mm high adjacent to the manway: (a) paints used,

(b) number of coats and order in which applied,

(c) contractors name and

(d) date of painting.



APPENDIX A APPROVED EPOXY COATING SYSTEMS The following are approved for use as internal epoxy linings in filter vessels, storage tanks and similar applications.

Manufacturer Product Code QPL reference Colours Ameron International Primer 3670900 Q1542 Ivory/white Finish 3623700 Ameron International Primer 3671000 Q1543 Ivory/white Finish 3623700 Ameron International 10056.01 Q1621 Buff/White 10056.12

Primer 744K8994 Q1429 Yellow/white Ameron (was Devoe Coatings Company) Finish 744K3978 Hempel Primer 85210-21240 Q1549 Yellow/white Finish 85210-11630 Hempel Hempadur 1540 --------- Light red/red/white (3 coat system)

Primer EPA5058H Q1618 Buff/White International/Courtaulds Coatings Finish EPA5059H Sherwin Williams Primer 920-Y-264 Q1556 Yellow/white Finish 920-Y-A18 Sigma Coatings 7315-3012-00 Q1606 Cream/White 7915-7001-00 Southern Coatings Primer 37-2190 Q1500 Yellow/white Finish 37-2191 Valspar Corporation Primer 578-D-3K Q1554 Buff/White Finish 578-W-3K British Paints Luxepoxy 4 --------- White finish (4 coat system) Copon System 12A Primer Copon EA9 --------- Middle Copon EA5

Red/light grey/ off white

Finish Copon EA5



Manufacturer Product Code QPL reference Colours Taubman System 944 ---------- Jotun Naviguard ---------- Jotun 'Sovapon" Primer 264D2 (Mil-P-23236) Buff/grey/white Middle 264F2 Finish 264W2 The paints tabled above are either on the QPL-4556 Issue 27 list or are paints with which we have had considerable experience. Other paints claim to meet the requirements of Mil-C-4556E but, at least in some cases, have not been subjected to the full test - mostly with respect to time; they have not yet appeared in the QPL-4556 list. These and other paints may be capable of passing the full test but using such paints requires caution; it is preferred to use paints which are on the QPL or with which we have experience or positive knowledge of their suitability. Prior to using coatings other than those listed above, approval must be obtained from Manager Design & Engineering, COE. COATING SUPPLIER ADDRESS LISTING Ameron International Sherwin Williams 201 N. Berry Street 101 Prospect Avenue P.O. Box 1020 Cleveland, OH 44115 Brea, CA 92622-1020 216-566-2000 714-529-1951

Sigma Coatings Devoe Coatings Company Amsterdamseweg 14 4000 Dupont Circle 1422 AD Uithoorn, Netherlands Louisville, KY 40207 (31) 297-541911 502-897-9861

Southern Coatings Hempel Coatings P.O. Box 160 6901 Cavalcade Sumter, SC 29151 Houston, TX 77028 803-775-6351 713-672-6641

Valspar Corporation International/Courtaulds Coatings 1401 Severn Street 5808 Martin Glen Road Baltimore, MD 21230 Midlothian, VA 23112 410-625-7200 804-739-9839


Date of Issue: June 2004 Table of Contents Revision Number: Original Issue Section 3 Page 1

SECTION 3 TABLE OF CONTENTS

3.0 PIPEWORK 3.1 DESIGN AND INSTALLATION STANDARDS 3.2 EQUIPMENT MARKING FOR PRODUCT IDENTIFICATION 3.3 TRUCK/REFUELER LOADING & UNLOADING FACILITIES 3.4 REFUELING EQUIPMENT FLOW TEST RIGS


Date of Issue: June 2004 Pipework Design and Installation Standards Revision Number: Original Issue CTGA 3.1 Page 1

CTGA SPECIFICATION 3.1 PIPEWORK DESIGN AND INSTALLATION STANDARDS

1.0 GENERAL

1.1 This Specification provides guidelines for the selection and installation of pipe and fittings for aviation fuel service at airport depots, supply terminals and refineries which supply direct to an airport.

1.2 Quality control considerations in handling aviation fuels require that pipework be

designed and installed to eliminate the possibility of product contamination from the pipework itself or from other products and that any accumulation of free water or particulate matter in the system can be readily removed.

2.0 REFERENCE PUBLICATION

2.1 ANSI B31.4 Liquid Petroleum Transportation Piping Systems 2.2 API Standard 1104 for Welding Pipelines and Related Facilities 2.3 API Specification 5L, Specification for Line Pipe 3.0 PIPING LAYOUT - DESIGN CRITERIA

3.1 Each grade of aviation fuel shall be handled in a completely segregated and dedicated system on both the receiving and discharge sides of the storage tank. Locations which receive product via non dedicated or unsegregated systems require approved isolation (double black and bleed valves, jack spools, removable spools, hammer blinds) on both the inlet and outlet of each tank if there are two (2) or more tanks; isolation on only the inlet is sufficient if there is only one (1) tank in a grade.

3.2 Pipelines used for product discharge into hydrant systems and for loading fuellers

shall not be used for receiving product into storage.

3.3 Long pipelines within an installation should be sloped at 0.5% towards a low point. Water drainage facilities (usually a plug) shall be provided at all low points to facilitate drainage for maintenance. A further benefit of providing a deliberate slope is that unintentional droops in the line are avoided thus helping to prevent accumulations of water with its attendant problems.

3.4 Inter-connecting lines shall not be installed between pipelines that handle different

grades of aviation fuel. If they must be provided they shall include removable spool pieces so that the different aviation grade systems are completely segregated during operations.



3.5 Copper alloys, cadmium plating, galvanized steel or plastic materials shall not be used

for piping or fittings in aviation service. 3.6 Pipelines should be grouped as much as possible and laid out in parallel above ground

so far as this can be done without unduly increasing the length of lines.

3.7 Complicated manifolding and dead legs should be avoided as far as is possible; a dead leg may be defined as a dead end pipe with a length greater than the pipe diameter.

3.8 All inlet and outlet piping shall be fitted with Millipore testing points (refer CTGA

4.3).

3.9 Low point sampling lines shall be three-fourths () inch (19mm) stainless steel with ball valves and quick disconnect couplings with dustcaps and shall have product identification tags attached.

3.10 All new carbon steel pipe which is downstream of a Filter Water Separator shall be

internally coated in accordance with CTGA 2.5. Where existing lines are not internally coated, these may continue in service provided monthly Colorimetric and quarterly Gravimetric membrane tests are satisfactory.

Note: Pickled black steel may be used unlined in certain circumstances for supply

pipelines - refer CTGA 2.5.

3.11 Airport piping systems shall include a test rig in accordance with CTGA 3.4.

3.12 All pipelines shall be clearly grade marked and color coded in accordance with CTGA 3.2.

4.0 SELECTION OF PIPE

4.1 The pipe material shall be standard black carbon steel pipe conforming to API 5L

Grade B or better.

4.2 The pipe shall be schedule 40 with a preference for seamless pipes. All hydrant pipes shall be seamless. Butt welded pipe shall not be used.

4.3 The pipe shall be flawless and should be free from inclusions, pits, folds, etc.

4.4 Each length of pipe shall be identified as to the manufacturer, size, weight, grade and

process of manufacture. 4.5 Only new pipe shall be used in aviation fuel service.

4.6 Pipelines should be sized for a normal flow velocity of 7 ft./sec. (2.1m/sec.) to provide a self-cleaning action. Prolonged use of pipelines at velocities much below 7 ft./sec



will result in accumulation of water, rust scale, microbial growth, etc. at low points. The flow velocity must not exceed 15 ft./sec. (4.5 m/sec) to avoid hazardous build-up of static electricity charges. The following chart provides approximate pipe sizes and flow rates corresponding to velocities of 3, 7 and 15 feet/sec.

VELOCITIES IN PIPELINES

SCHEDULE 40 PIPE FLOW RATES IN U.S.G.P.M.

Nominal Diameter

Inside Diameter 3 ft/sec Velocity 7 ft/sec Velocity

15 ft/sec Velocity

2 2.067 30 75 160 3 3.068 70 160 340 4 4.026 120 280 600 6 6.065 270 630 1,350 8 7.981 470 1,090 2,340 10 10.020 740 1,720 3,690 12 11.938 1,050 2,440 5,230 14 13.124 1,260 2,950 6,320 16 15.000 1,650 3,860 8,270 18 16.876 2,090 4,880 10,460 20 18.812 2,600 6,060 12,990 24 22.624 3,760 8,770 18,800

Notes: (1) 3 ft/second is the maximum allowed velocity for splash loading, i.e. initial

filling of a tank before the fill line is submerged.

(2) 7 ft/second is the recommended velocity for pipelines to provide a self-cleaning action.

(3) 15 ft/second is the maximum allowed velocity in any pipeline to avoid the

build-up of hazardous static charges.

4.7 Micronic filters and filter separators increase the static electrical charge in the body of fuel passing through it and, in order to avoid the possibility of a spark discharge, sufficient time must be allowed downstream of a filter for the static charge to dissipate to a safe level before the product enters a tank or other vented vessel. The time required for the charge to dissipate

aviation manual chevron-texaco

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