piping types and systems a brief surway

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PIPING AND PIPING SYSTEMS

Introduction

Definition of Piping

Pipe is a pressure tight cylinder used to convey a fluid or to transmit a fluid pressure,

ordinarily designated pipe in applicable material specifications.

Or

It is a Tubular item made of metal, plastic, glass etc. meant for conveying Liquid, Gas or any

thing that flows.

Materials designated tube or tubing in the specifications are treated as pipe whenintended for pressure service. Piping is an assembly of piping components used to convey,

distribute, mix, separate, discharge, meter, control or snub fluid flows. Piping also includes pipesupporting elements but does not include support structures, such as building

frames, bents, foundations, or any equipment excluded from Code definitions.

Piping components are mechanical elements suitable for joining or assembly into pressure-

tight fluid-containing piping systems. Components include pipe, tubing, fittings, flanges,gaskets, bolting, valves and devices such as expansion joints, flexible joints, pressure hoses,

traps, strainers, in-line portions of instruments and separators.

Piping is typically round.

Piping Nomenclature, Components

Graphic of piping system illustratingHeader

Branch connectionValve

FlangeExpansion joint

Expansion loopPipe support



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Reducer El

Fl w i i

Average vel cit i a pi pe

Recall - because of t e no-sli p condition, t e velocit at t e walls of a

pi pe or duct f low is zero

We are of ten interested onl in V avg , which we usuall call just V (drop

the subscr i pt for convenience)

K eep in mind that the no-sli p condition causes shear stress and fr ictionalong the pi pe walls.

Fr iction force of wall on f luid

For pi pes with var iable diameter,m is still the same due to conser vation of mass, but

V 1 V 2



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Definition of Reynolds number

Critical R eynolds number (R ecr ) for flow in a round pipe

R e < 2300 laminar

2300 R e 4000 transitional

R e > 4000 turbulent

Note that these values are approximate.For a given application, R ecr depends upon

Pipe roughness

Vibrations

Upstream fluctuations, disturbances (valves, elbows, etc. that may disturb the

flow).



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For non-round pipes, define the hydraulic diameter

Dh = 4 Ac /P

Ac = cross-section area

P = wetted perimeter

The Entrance Region

Consider a round pipe of diameter D. The flow can be laminar or turbulent. In either case,

the profile develops downstream over several diameters called the entry lengt h Lh. Lh/ D is a

function of R e.



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Full Devel ed Pi e Fl w

In compar ison of laminar and turbulent f low

There are some ma jor differences between laminar and turbulent full developed pi pe f lows

Lami ar

Can solve exactl (Chapter 9)

Flow is steady

Velocity prof ile is parabolic

Pi pe roughness not impor tant

It turns out that Vavg = 1/ max and u(r)= 2Vavg(1 - r 2/R

2)



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Turbulent

C annot solve exactly (too complex)

Flow is unsteady (3D swir ling eddies), but it is steady in the mean

Mean velocity prof ile is fuller (shape more li e a top-hat prof ile, with

very sharp slope at the wall)

Pi pe roughness is very impor tant

Vavg 85% of Umax (depends on Re a bit)

Recall, for simple shear f lows u=u(y), we had

X = Qd u / d y

In fully developed pi pe f low, it turns out that

X = Qd u / dr

There is a direct connection between the pressure drop in a pi pe and the shear stress at the

wall.Consider a hor izontal pi pe, fully developed, and incompressi ble f low.Let¶s apply

conser vation of mass, momentum, and energy to this CV.



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By using the law of conser vation of Mass & law of Conser vation of x-momentum we get

following results



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Compressible Flow T rough Pipes

Mass Balance

S is constant

Differential Balance

Mechanical Energy Balance

Total Energy Balance

21

uS uS V V !

21

uu V V !

21GG !

0

11

! dx

d

dx

d V

V

W dx

dh

dx

dp

dx

dz g

dx

d

f Ö1

!¹¹ º

¸©©ª

¨¹

º

¸©ª

¨¹ º

¸©ª

¨¹ º

¸©ª

¨ V

E

0

2

412

!¹

º

¸©

ª

¨¹

º

¸©

ª

¨ u

D

f

dx

dp

dx

d uu

V



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Note: This indicates that there must be heat transfer becausedT = 0. This is the heat

required to keep T constant.

Piping Network s

Two general types of networks

Pipes in series:Volume f low rate is constant and Head loss is the summation of par ts.

Pipes in parallel:Volume f low rate is the sum of the components and Pressure loss across all

branches is the same.

c pW

dx

dQ

dx

dT C

dx

dz g

dx

d uum Ö!¹

º

¸©ª

¨ E

dx

dQ

mdx

duu

1!



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Solution Methods for Piping Systems in Series and Parallel

1. Series Pipe Line Sys¡

ems a. Class I: Flow rate (Q) and pipe diameter (D) are known, loss head (hL) is unknown.

i. Write down energy equation, P1/K + z1 + v12/2g + hA hL hR = P2/K + z2 +

v2

2/2g

ii. Solve for the unknown or required output (e.g. hA, etc.).

iii. Identif y all the terms that make up hL, such as pipe losses, hL = f (L/D)v2/2g

and minor losses, hL = Kv2/2g.

iv. By using Q, Q = v*T/4*D2, and D, solve for the velocity, v and determine the

Reynolds number, Re, and the loss coefficient, K.

v. By using the Reynolds number, Re and D/I, determine the friction factor, f,

by using the Moody Diagram or the appropriate friction factor equation. For

minor losses, find f T (if required) by using D/I only.vi. Determine hL and find the required output (e.g. hA, etc.).

b. Class II: Pipe diameter (D) and pressure drop, (P, are known, flow rate, Q, is

unknown.

i. Write down the energy equation, P1/K + z1 + v12/2g + hA hL hR = P2/K + z2 +

v2

2/2g

ii. Separate known variables from unknown variables. Put the known variables

on the left hand side of the equation, and the unknowns on the right side.



iv. Since flow rate, Q, is unknown, express hL as a function v and f, and solve forv.

v. Use D/Ito estimate an initial guess value for f , and find v.

vi. Use the calculated v to determine the Reynolds number, Re, and determine

a new f value.

vii. Find v (velocity) and repeat step vi until the f value converges to a steady

value.

viii. Determine the flow rate, Q.

c. Class III: Pressure drop, (P, and flow rate, Q, are known, D is unknown.

i. Write down the energy equation, P1/K + z1 + v12/2g + hA hL hR = P2/K + z2 +

v2

2/2gii. Separate known variables from the unknown variables. Put the known

variables on the left hand side of the equation, and the unknowns on the

right side.





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iv. Solve for D by using Q = v*T/4*D2 , and express it in terms of hL and f .

v. Make an initial guess value for f (between 0.01 and 0.1, f = 0.02 is usually a

good initial guess), and find D.

vi. Determine Re and D/I, and compute a new f value.vii. Find D and repeat step vi until the f value converges to a steady value.

viii. Determine D.

2. Parallel Pipe Line Systems

a. Two branches, total flow rate, Q, and D are known. Total pressure drop (or total

head) and individual branch flow rates are unknown.

i. Identif y all the terms that make up hL, such as pipe losses, hL = f (L/D)v2/2g

and minor losses, hL = Kv2

/2g for each branch.ii. Since the flow rate for each branch, Q i, is unknown, express hL for each

branch as a function of velocity, v1 or v2 and f 1 or f 2.

iii. Equate the two hLs and express them in terms of f 1 and f 2 and v1 or v2. Solve

for one velocity.

iv. Make an initial guess value for f 1 and f 2 (between 0.01 and 0.1), and by using

Q total = Q 1 + Q 2, find v1 and v2, determine Re1 and Re2, D1/I1 and D2/I2, and

find f 1 and f 2.

v. Repeat steps iii and iv until f 1 and f 2 converge to steady values.

vi. Determine Q 1 and Q 2, and h1 and h2.

Note: If k values are given for each branch (hL1 = K1v1

2

/2g and hL2 = K2v2

2

/2g), then solve forone of the velocities by equating hL1 = hL2 and using Q total = Q 1 + Q 2. Then determine Q 1 and

Q 2.

b. Two branches, total pressure drop (or total head) is known. Total flow rate and

individual branch flow rates are unknown.

i. Identif y all the terms that make up hL, such as pipe losses, hL = f (L/D)v2/2g

and minor losses, hL = Kv2/2g for each branch.

ii. Since the flow rate for each branch, Q i, is unknown, express v1 and v2 for

each branch as a function of h1 and h2, respectively.

iii. Since the pressure drop is known, find h1 and h2.( hL = h1 = h2)iv. Determine v1 and v2 by making initial guesses for f 1 and f 2 (between 0.01 and

0.1), and by using Q total = Q 1 + Q 2, if necessary. Once v1 and v2 are computed,

determine Re1 and Re2, D1/I1 and D2/I2, and find f 1 and f 2.

v. Repeat steps iv until f 1 and f 2 converge to steady values.

vi. Determine Q 1, Q 2 and Q Total, and h1 and h2.



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Note: If k values are given for each branch (hL1 = K1v1

2/2g and hL2 = K2v2

2/2g), then find each

velocity v1 and v2 and find Q total = Q 1 + Q 2.

Types of Pipe

The heart of any plumbing system is pipe. There are three main

types of materials pipe can be made from - galvanized steel,

copper, or plastic. And it's important that, when making

repairs or modifications to an existing system, you use the sametype of pipe. Galvanized pipe systems are rarely used in new

residential construction. If your home is more than 20 yearsold, however, chances are very good that the supply lines are

made of galvanized pipe.

Copper pipes come in four types - type K, type L, type M, and DWV. Type K has the thickest

walls and is most frequently used for underground service lines in the supply system. Type L

is used for interior hot and cold water supply lines. Type M is the thinnest of the types and is

also used for interior hot and cold water supply lines. DWV pipes are used for the drain-

waste system and for the vent system.

Plastic pipes are easy to work with, light-weight, and durable. Because of these reasons,

plastic pipe has become the most popular pipe for do-it-yourselfers to use and there are five

main types, each designed for specific applications. PVC pipes are white and are approvedfor cold water use only. PVC - DWV pipes are also white, but are approved for use in drain-

waste systems or vent systems. CPVC pipes are beige and are approved for use in hot or cold

water service lines. Polyethylene tubes are black and approved for cold water use. And

Polybutylene is gray or beige and is usually sold in coiled lengths. Polybutylene is the only

flexible pipe approved for hot and cold service lines.

1.Cast iron pipe

The cast iron pipe is heavy, but it is very durable and very common. Compared to plastic, the

cast iron pipe will be much quieter, and a lot more durable, and will better withstand

chemical and mechanical pipe-cleaning equipment.



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2.Galvanized steel pipe

Galvanized steel pipes are available in different lengths and diameters, and have an anti-rust

coat on their outside and insides. Connections are usually made by cutting threads into the pipes, this may be problematic, as the cutting is made after the pipe was anti-rust coated so

any exposed cut part will rust. These pipes are very strong, and will last for a long time, they

are often used for the transporting of gas as well as water. Galvanized steel pipes are rough,

and after years of usage, mineral from the water that runs in them will accumulate on the

inside and narrow the diameter of the pipe, which is of course an unwanted outcome.

3.Copper pipe

Copper pipes are considered excellent pipes; they come in varieties of soft, flexible, and hard,have a long life expectancy, and are not affected by corrosion. It will be the best option to

supply hot/cold water to a modern house. The price for copper pipes is a little higher than

other types of pipes and so is their installation. Connections are made by soldering two

copper pipes to a copper connection piece. These pipes can be bent or curved relatively

easily, which is a great advantage not available with other types. Copper pipes require

pressure chambers to avoid the ³water hammer´, a sound they may produce when a sudden

turning on/off of water occurs.

4.Plastic pipes

Plastic pipes are the cheapest of all types, it is also simple to install, therefore has low labor

costs too. Connections are made easily through cutting of the plastic pipe, plastic fittings, can

of plastic cement, and a brush. Its weight is very light, making it easy to support, and it will

not corrode. Though, plastic pipes are not strong as other materials, nor can they bend as

copper, they tend to crack under heavy loads. They will also be very noisy when water runs

through them.

You can use different types of pipe materials in your house, using the advantages each

material has to get maximum efficiency, productivity and lower costs.



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NOW WE WILL SEE THE DETAIL OF EVER Y PIPE TYPE IN DETAIL

COPPER PIPE

y There are two basic types of copper pipe or tubing: rigid and flexible.

y R igid pipe, usually installed in new homes, makes a neater installation, but it is much

more difficult to install than soft, flexible copper pipe.

y Flexible copper pipe is best for repair work since it can be run around obstacles

without connections or cuts.

y Copper pipe is available in three basic types: Type M is thin-walled, Type L is

medium-walled and Type K is thick-walled. In most cases, Type L is good for home

use. Check your city code to determine which type of pipe is required for the work

you're planning.

Copper pipe and tube comes in a variety of types, with different wall thicknesses, ductility

and intended used. The difference between copper pipe and copper tube is the the way thediameter of the pipe is measured. Copper tube is measured by outside diameter (OD) whereas

copper pipe is measured by inside diameter (ID). Depending on the plumbing job you aredoing, local and national plumbing codes will dictate which type of copper pipe is acceptable.

Type L copper pipe

Type L copper pipe and tube has a thicker wall than type M and DWV pipes making it the

preferred choice for longevity. There are two kinds of type L; Hard, and soft temper. Type L

will be marked with blue along the pipe or tubing.

Hard temper type L plumbing applications include:

y Above ground water distribution

y Above and below ground drainage and venting systems

y Building sewer

Soft temper type L plumbing applications include:

y Water service pipey Water distribution above and below ground



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Type M copper pipe

Type M copper pipe and tubing is commonly used in residential plumbing because it has thinwalls and can be produced and sold at a much lower cost. For water distribution longevity

type M is not recommended. Type M copper is also better for heating applications because of

the thin wall thickness. Type M is identified with R ED markings along the pipe.

Hard temper type M plumbing applications include:

y Above ground water distributiony Above ground drainage systems

Soft temper type M shall not be used in plumbing systems.

Type K copper pipe

Type K copper pipe and tube is the most robust of the four types because it has the largest

wall thickness. Type K comes in hard and soft temper and will be identified by green

markings. Type K copper can be used for many other applications such as : Fuel, gasses,

HVAC, fire protection systems and vacuum systems to name a few.

Hard temper type K plumbing applications include:

y Above ground water distributiony Above and below ground drainage and venting systems

y Building sewer

Soft temper type K plumbing applications include:

y Water service pipe

y Water distribution above and below ground

DWV copper pipe

DWV copper pipe is used for drainage waste and vent (DWV), above ground only and is

identified by yellow markings.



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Steel Pipes

When carbon is added to iron, it manages to change its properties

greatly, forming steel. In total, there are several thousand differenttypes of steels, all with different chemical compositions. Steel

tubing can be designed and fabricated to any length and strength

and are used in automotive, appliance, construction and

manufacturing markets.

y Line Steel Pipes

y Standard Steel Pipes y Structural Steel Pipes

y Plumbing Tubes

Plastic pipes

Polyvinyl chloride (PVC) pipe fills plumbing needs all over the world. Cheap, stable and easy

to work with, it has become the material of choice for most plumbing needs. PVC pipe is

sized according to the nominal inside diameter of the pipe. A 2-inch pipe will therefore be

referring to the interior dimension of the pipe, since the exterior diameter will be greater. Asthe walls of pipes get thicker, the outside dimensions stay the same and the inside diameter

shrinks to accommodate the thicker walls.

Schedule 40

The most commonly used type of PVC pipe is Schedule 40. These pipes are white in color

and have the largest inside dimension of the three schedules. The main drawback to Schedule40 is that it is only rated to handle temperatures up to 140 degrees Fahrenheit, meaning that it

cannot be used for hot water systems. Schedule 40 is used for drains, vents and cold water

supply.

Schedule 80

Schedule 80 pipe is sometimes found in houses, but more often it is used in commercialapplications. The inner diameter of this pipe is a little bit smaller than the comparable



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Schedule 40 pipe due to the thicker side walls. Like Schedule 40, it is used for drains, ventsand cold water supply. To differentiate it from Schedule 40, this pipe is gray in color.

Schedule 120

This pipe has the thickest walls of the three, and therefore the smallest inside diameter in

comparably sized pipes. Schedule 120 is usually only found in commercial applications due

to its higher costs. While it also comes in white, it is hard to confuse it with Schedule 40 as it

is much thicker and heavier. It is also only available at commercial plumbing houses.

CPVC

Chlorinated polyvinyl chloride pipe (CPVC) is the newest version of PVC pipe. It can

withstand heat up to 180 degrees Fahrenheit, so it is suitable for domestic hot water systemsand is available in the same schedules and uses the same color schemes.

Variations.

PVC pipe used for nonpotable water--water that can't be used for drinking--is green in color

so that it isn't accidentally installed with standard PVC pipe in a water supply system.

Gray Schedule 40 does exist, but only for use as electrical conduit, and this is stamped all

over the outside of the pipe. It also does not exactly match the outside diameters of pipe usedfor water systems.

COMMON PIPE FITTINGS



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PIPING SYSTEMS

1.Fuel oil piping systemThis shall apply to piping systems and their components used to transfer fuel oil from

storage and supply tanks to oil-burning appliances and equipment.

Acceptable Piping Materials and Piping System Design.

Tank fill and vent piping shall be wrought-iron, steel, or Schedule 40 brass pipe. Oil

supply lines shall be steel pipe or brass or copper tubing. Wall thickness of wrought-

iron and steel pipe shall comply with the specifications in ANSI/ASME B36.10,

S tandard on Welded and S eamless Wroug ht S teel Pipe.

Piping shall be permitted to be of materials other than those specified if used

underground and back-filled or if used as part of an engineered fuel storage system.

Such piping shall be designed in accordance with good engineering practice for the

material used and shall be approved by the authority having jurisdiction. Such piping shall be installed in accordance with manufacturers instructions.

Listed flexible metal hose shall be permitted to be used where rigid connections are

impractical. It shall be installed in full compliance with its listing.

Piping used to connect oil burners and oil-burning appliances to their fuel supply

shall not be smaller than 3/8-in. (9.5-mm) iron pipe size or 3/8-in. (9.5-mm) O.D.

tubing. Copper tubing shall have 0.035-in. (0.89-mm) nominal and 0.032-in. (0.81-mm) minimum wall thickness.

Exce pt ion No. 1: 1 / 4-in. (6.4-mm) pipe or 5 / 16 -in. (7.9-mm) O. D. tubing shall be permitted to

be used in t he suct ion l ine of systems where t he to p of t he tank i s below t he level of t he oil

pum p.

Exce pt ion No. 2: C onversion range oil burners need not meet t hese requirements.

Pipe shall be connected wit h standard f itt ings and tubing wit h f itt ings of l i sted ty pes.

y Pipe connectors made of combustible materials or dependent on the frictionalcharacteristics of combustible materials shall not be used inside of buildings or

aboveground outside of buildings. Such connectors shall be permitted to be usedunderground if of listed type and installed in accordance with their listing.

y All threaded joints and connections shall be made tight with suitable lubricant or pipe compound.

y Unions requiring gaskets or packings, right or left couplings, and sweat fittings

employing solder having a melting point of less than 1000°F (538°C) shall not be

used in oil lines.y Cast-iron fittings shall not be used.

y Piping shall be substantially supported and protected against physical damage and,

where necessary, protected against corrosion. All buried piping shall be protected

against corrosion.

y Proper allowance shall be made for expansion, contraction, jarring, and vibration.



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y Pipe lines connected to underground tanks shall be provided with double swing joints or flexible connectors, or shall be otherwise arranged to permit the tanks to

settle without impairing the tightness of the pipe connections.

Exce pt ion No. 1: Tubing need not meet t hese requirements. Exce pt ion No. 2: S trai g ht f ill l ines and test wells t hat have no changes in d irect ion need not

meet t hese requirements.

y Piping systems shall be maintained l iquid t i g ht. A piping system t hat leaks shall beem pt ied of l iquid or re paired in an a pproved manner.

y F uel oil shall not be transferred to an oil -burning a ppl iance by pressur izing t he tank wit h air or ot her gas.

Tank Fill Piping.The fill pipe shall be large enough and so located as to permit ready filling in a manner that

minimizes spills. The fill pipe shall terminate outside the building at a point at least 2 ft (0.6m) from any building opening at the same or lower level. The fill pipe shall terminate in a

manner that minimizes spills when the filling hose is disconnected. The end of the fill pipe

shall be equipped with a tight metal cover designed to discourage tampering and shall be

identified as a fuel oil fill.

Exce pt ion: A crank case oil or used oil f ill pipe for a tank d irectly serving a used oil f ired

burner and a ppl iance shall be permitted to terminate indoors in accordance wit h N F PA

30 A , C ode for Motor F uel Di s pensing F acil it ies and Re pair Garages. If t he f ill pipe has a

funnel -ty pe o pening , t hen it shall be provided wit h a read ily accessible manual shutoff valve

of t he 1 / 4-turn-to-close ty pe , between t he funnel -ty pe o pening and t he tank.

Cross-connections that allow gravity flow from one tank to another shall be prohibited.

Exce pt ion: Two su pply tanks whose aggregate ca pacity does not e xceed 660 gal (2500 L )

shall be permitted to be cross-connected as s peci f ied in 7.5.15.

Piping for Auxiliary Tanks.

An overflow pipe from an auxiliary tank shall have no valves or obstructions.

Fuel Return Piping.

A return line from a burner or pump to a supply tank shall have no valves or obstructions

and shall enter the top of the same tank.

Supply Piping to Oil-Burning Appliances.

All piping shall be connected into the top of the supply tank. Where two tanks are cross-

connected, the tops of the tanks shall be on the same horizontal plane

Exce pt ion No. 1: T he burner su pply l ine from a tank t hat does not e xceed 660 gal (2500 L )need not meet t hi s requirement.

Exce pt ion No. 2: T he cross-connect ion between two tanks having an aggregate ca pacity

t hat does not e xceed 660 gal (2500 L ) need not meet t hi s requirement.

The pressure at the oil supply inlet to an oil-burning appliance shall not exceed 3 psig (gage

pressure of 21 kPa).



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Exce pt ion: An a ppl iance t hat i s a pproved for a hi g her inlet pressure.

Where supply tanks are set below the level of the burner, the oil piping shall pitch

toward the supply tank. The piping shall not have traps.

For commercial and industrial installations, the oil supply from tanks of any capacity permitted by this standard shall meet the following requirements:

(1) The burner supply line shall be permitted to be connected to an outside abovegroundsupply tank at a point below the liquid level, but each such connection shall be

provided with an internal or external shutoff valve located as close as practicable tothe shell of the tank. External valves and their connections to the tank shall be of

steel.

(2) A transfer pump shall be permitted to be used.

Vent Piping.

Vent pipes shall drain toward the tank or toward one tank where two tanks are cross-

connected. The vent pipes shall have no sags or traps where liquid can collect. Vent pipes

shall be located so that they are not subjected to physical damage.

The lower end of the vent pipe shall enter the tank through the top and shall extend

into the tank not more than 1 in. (25 mm).

Vent pipes shall terminate outside of buildings at a point not less than 2 ft (0.6 m)

measured vertically or horizontally from any building opening. They shall terminate

high enough above the ground to avoid being obstructed with snow and ice.

The outer end of the vent pipe shall terminate in a weatherproof vent cap or fitting or

shall be provided with a weatherproof hood. Vent caps shall have a minimum free

open area equal to the cross-sectional area of the vent pipe and shall not employ

screens finer than No. 4 mesh.

Vent pipes from tanks containing heaters shall extend to a location where oil vapors

discharging from the vent will be readily diffused. If the static head with a vent pipe filled with oil exceeds 10 psig (gage pressure of 70

kPa), the tank shall be designed to withstand the maximum static head that will be

imposed.

Vent pipes from more than one tank shall be permitted to be manifolded and

connected into one outlet pipe. The outlet pipe shall be at least one pipe size larger than the largest individual vent pipe connected thereto. In no case shall the point of

connection between two or more vent pipes be lower than the top of any fill pipeopening.

The vent outlet of a supply tank shall terminate at least 5 ft (1.5 m) from any air inletor any flue gas outlet of any appliance.

Vent pipes shall not be cross-connected with pipes other than vent pipes.



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2. Flexible Piping Systems

Flexible piping systems are widely used in the petroleum industry because they are environmentally safe and easy-to-install. Flexible piping is corrosion resistant and eliminates piping joints within a run

because it uses continuous runs. Most flexible piping systems can be used as both pressure and

suction product lines.

Flexible Piping Do's (COMAR 26.10.03.06)

Can be used for all underground product lines associated with petroleum products.

Can be used for suction, pressure, and return lines.

Must be installed in accordance with the piping manufacturer's specifications and COMAR

regulation.

Must use piping and components listed by an approved testing laboratory such as

Underwriters Laboratory (UL).

Flexible Piping Don¶t's

Cannot be used for Stage II or vent application s because of trap formation that will cause

vent-breathing problems in the tank.

Cannot be used for aboveground use.

Recommendations for Flexible Piping

Before beginning a marina application of flexible piping (usually for dispensers on piers)

check with MDE.

Although flexible piping can be buried directly, MDE recommends piping be run in an UL-

listed duct, conduit, or chase. Consult the piping manufacturer for ducts, conduits, or chases.

MDE recommends that the piping terminate in liquid-tight sumps that are located under thedispenser and at the tank top.

MDE recommends that routine checks be made of pipe couplings during operations because

couplings and related gaskets are the areas most likely to develop leaks.



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MDE recommends using "Loctite" products on flexible piping thread connections.

MDE recommends all underground storage tank system owners and technicians verify the

UL listing status of any new petroleum storage system products before use.

3.Grooved Piping SystemThe only system that provides the option of rigidity or flexibility

The Victaulic grooved piping system is the most versatile, economical

and reliable piping system available. It is up to three times faster toinstall than welding, easier and more reliable than threading or flanging,

resulting in lowest total installed cost.The system is designed for roll grooved or cut grooved standard pipe or

roll grooved light wall pipe. Pipe end preparation is fast and easy either in the shop or on the job site with a variety of Victaulic grooving tools

available.

In addition to speed and ease of assembly, the Victaulic system offers

varied mechanical benefits to the designer, installer and owner. With the

introduction of Zero-Flex® rigid couplings, the option of flexibility or

rigidity adds to the design versatility. Flexible and rigid couplings can

be incorporated as needed in any system to take full advantage of the

characteristics of each.

Victaulic also offers the Advanced Groove System (AGS) for 14 ± 24"

(350 ± 600 mm) sizes.

Installed cost savings from 10% to 30% Minimal equipment investment

Fast assembly in tight places

Clean system. . . no pipe dope or welding slag to contaminate pipes Costs are more predictable. . . estimates more accurate



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Each joint is a union Removal of two couplings permits removal of pipe section for cleaning or servicing

Easy future add-on, change or renovation of pipe to distribute internal wear from abrasives or slurries

Proven joint reliability Full circumferential engagement of housing into groove provides end pullStrength

Couplings available for working pressures to 2,500 psi (17,235 kPa). . . vacuum services to 29.9" Hg

For roll or cut grooved pipe Victaulic tools permit rollgrooving standard steel pipe up to 42" (1050 mm) in 0.375" (9,5 mm) wall thicknesses

Couplings fit either roll or cut grooved pipe Roll grooving permits use on pipe from Schedule 5 to Schedule 40 Pipe of different wall thickness and material can be connected directly and intermixed.

4.Thermoset Piping Systems

Thermoset piping systems are composed of plastic materials and are identified by being

permanently set, cured or hardened into shape during the manufacturing process. Thermoset

piping system materials are a combination of resins and reinforcing. The four primary

thermoset resins are epoxies, vinyl esters, polyesters, and furans. Other resins are available.

Thermoset Piping Characteristics

Advantages of thermoset piping systems are a high strength-to-weight ratio; low installation

costs; ease of

repair and maintenance; hydraulic smoothness with a typical surface roughness of 0.005 mm(0.0002 in);flexibility, since low axial modulus of elasticity allows lightweight restraints and reduces the

need for expansionloops; and low thermal and electrical conductivity. Disadvantages of thermoset piping

systems are lowtemperature limits; vulnerability to impact failure; increased support requirements, a

drawback of the lowmodulus of elasticity; lack of dimensional standards including joints since pipe, fittings,

joints and adhesives

are generally not interchangeable between manufacturers; and susceptibility to movement

with pressure surges,

such as water hammer.

Corrosion R esistance

Like other plastic materials, thermoset piping systems provide both internal and external corrosion resistance.

For compatibility of thermoset plastic material with various chemicals, see Appendix B. Due to the different



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formulations of the resin groups, manufacturers are contacted to confirm material compatibility. For

applications that have limited data relating liquid services and resins, ASTM C 581 provides a procedure to

evaluate the chemical resistance of thermosetting resins.

Materials of Construction

Fiberglass is the most common reinforcing material used in thermoset piping systems because of i ts low cost,

high tensile strength, light weight and good corrosion resistance. Other types of commercially available

reinforcement include graphite fibers for use with fluorinated chemicals such as hydrofluoric acid; aramid;

polyester; and polyethylene. The types of fiberglass used are E-glass; S-glass for higher temperature and tensilestrength requirements; and C-glass for extremely corrosive applications.

Most thermoset piping systems are manufactured using a filament winding process for adding reinforcement.

This process accurately orients and uniformly places tension on the reinforcing fibers for use in pressure

applications. It also provides the best strength-to-weight ratio as compared to other production methods. The

other main method of manufacturing is centrifugal casting, particularly using the more reactive resins.

Thermoset piping can be provided with a resin-rich layer (liner) to protect the reinforcing fibers. The use of

liners is recommended for chemical and corrosive applications. Liners for filament wound pipe generally range

in thickness from 0.25 to 1.25 mm (0.01 to 0.05 in), but can be custom fabricated as thick as 2.8 mm (0.110 in)

and are often reinforced. Liner thickness for centrifugally cast thermoset piping generally ranges from 1.25 to

2.0 mm (0.05 to 0.08 in); these liners are not reinforced. If not reinforced, liners may become brittle when

exposed to low temperatures. Impacts or harsh abrasion may cause failure under these conditions. Fittings are

manufactured using compression molding, filament winding, spray-up, contact molding and mitered

processes. Compression molding is typically used for smaller diameter fittings, and filament winding is used

for larger, 200 to 400 mm (8 to 16 in), fittings. The spray-up, contact molding and mitered processes are used

for complex or custom fittings. The mitered process is typically used for on -site modifications.

a. Operating Pressures and Temperatures

Loads; service conditions; materials; design codes and standards; and system operational pressures and

temperatures are established as for plastic piping systems.

5.Chilled Water Piping Systems (VPF Focus) Here we will study a system under the following headings

Primary (Constant) / Secondary (Variable ± 2W Valves)

Low Delta T

Primary Only (Variable Flow - 2W Valves)

Direct Buried Piping System

General: All underground piping for chilled water system distribution shall have a minimum

diameter of 4´ and shall be cement lined ductile iron.

Pipe Joint R estraint Calculations: Submit complete calculations for underground chilled water pipe joints indicating the requirements for restrained and push-on joints. Submission of output

data from an approved vendor computer selection/calculation program will be required to justify

the use of push-on joints in certain locations. This program shall utilize the depth of cover indicated on the profile drawings.



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Ductile Iron Pipe: Pipe shall conform to AWWA C151 minimum class 50. All ductile iron pipeshall be cement mortar lined in accordance with AWWA C104 and shall have asphaltic coating.

Piping 4´ ± 12´ shall have 350 psig minimum working pressure. Piping 14´ ± 24´ shall have a

300 psig minimum working pressure.

Select backfill material shall be provided for bedding and backfill 12´ above pipe.

System drains and vents ± Provide system drains at low points and system vents at high pointsaccording to details as attached.

Fittings: Fittings for ductile iron pipe shall be ductile iron and rated a minimum of 250 psiworking pressure. Fittings shall be cement mortar lined equivalent to the pipe lining.

Mechanical Joint Fittings: Comply with AWWA C110. Where restained joints are identified, use

Megalug Series 1100 system or approved equal. Gasket material shall be SBR

Push-on Joint: Comply with AWWA C111

Butterfly Valves: Comply with AWWA C504. Valve shaft to be type 304 stainless steel. Cast

valves from gray or ductile iron. Provide interior coating of body and disk. Valves shall be

furnished with buried service gearbox operator, shaft extensions, ground level position indicatorsand valve boxes.

Gate Valves: Comply with AWWA C509. Stem shall be non-rising and shall be cast bronze.

Valve body and wedge shall be ductile iron and shall be coated inside and outside with epoxy.The coating shall meet or exceed AWWA C550. Valves shall have a minimum pressure rating of

250 psi. Gate valves shall be US pipe or approved equal.

Valve Boxes: Valve boxes shall be 2 piece cast iron with heavy duty traffic weight lid markedwith valve number as shown on drawings (such as CWS ±22). Valve boxes not in paving shall be

supplied with a pre-cast concrete mowing ring.

STEAM AND CONDENSATE SPECIALITIES:

Materials: Steel pipe shall be ASTM A106, schedule 80, seamless, black steel with

beveled ends. Pipe shall be domestically produced and a mill certification shall be

provided.



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GAS DIST IBUTION SYSTEMS:

Underground gas pi ping will be high molecular weight polyethelene approved

for underground natural gas ser vice with thermal joints.

A bo

ve ground pi pingshall be steel or copper.

6.Heat Pipes

Advantages:

Ver y hi gh t her mal cond uct ivit y. Less temperature difference needed to transpor t heat

than traditional mater ials (thermal conductivity up to 90 times greater than copper for

the same size) (Faghir i, 1995) resulting, in low thermal resistance.

P ower fl att ening. A constant condenser heat f lux can be maintained while the

evaporator exper iences var iable heat f luxes.

E ff icient t ranspor t o f concent rat ed heat .

Temperature Control. The evaporator and condenser temperature can remain near ly

constant (at Tsat) while heat f lux into the evaporator may vary.

Geomet r y cont rol . The condenser and evaporator can have different areas to f it

var iable area spaces (Faghir i, 1995) . High heat f lux inputs can be dissi pated with low

heat f lux out puts only using natural or forced convection.



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Types of Heat Pipes

Thermosyphon- gravity assisted wickless heat pipe. Gravity is used to force the

condensate back into the evaporator. Therefore, condenser must be above the evaporator in a

gravity field.

Leading edge- placed in the leading edge of hypersonic vehicles to cool high heat fluxes

near the wing leading edge.

Rotating and revolving - condensate returned to the evaporator through centrifugal

force. No capillary wicks required. Used to cool turbine components and armatures for

electric motors.

C ryogenic- low temperature heat pipe. Used to cool optical instruments in

space.

Flat Plate- much like traditional cylindrical heat pipes but are rectangular. Used to cool

and flatten temperatures of semiconductor or transistor packages assembled in arrays on the

top of the heat pipe.

Micro heat pipes- small heat pipes that are noncircular and use angled corners as liquid

arteries. Characterized by the equation: rc /r hu1 where rc is the capillary radius, and r h is the

hydraulic radius of the flow channel. Employed in cooling semiconductors (improve thermal

control), laser diodes, photovoltaic cells, medical devices.

V ariable conductance- allows variable heat fluxes into the evaporator while

evaporator temperature remains constant by pushing a non- condensable gas into the



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condenser when heat fluxes are low and moving the gas out of the condenser when heat

fluxes are high, thereby, increasing condenser surface area. They come in various forms like

excess-liquid or gas-loaded form. The gas-loaded form is shown below. Used in electronics

cooling.

C apillary pumped loop heat pipe- for systems where the heat fluxes are very high

or where the heat from the heat source needs to be moved far away. In the loop heat pipe, the

vapor travels around in a loop where it condenses and returns to the evaporator. Used in

electronics cooling.

7.UNDERGROUND PETROLEUM PIPING

SYSTEMS

pipes must be either constructed of;

a non-corrodible material such as fiberglass reinforced plastic, nylon or engineered

thermo-plastic, or

metal such as steel with a cathodic protection system designed to protect it for 30

years.

- pipes may be in single or double-walled construction;

- access ports must be installed to permit tightness testing;

- installation must be in accordance with recognized engineering practices, and

- pipes and joints must be tightness tested before being covered and placed in use.

Other system requirements include impact valves at dispensers of motor fuel, overfill prevention equipment and a line leak detector for systems where the piping is operating under

pressure. Suction systems must not be equipped with more than one check valve.



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Piping calculations

Types of Pipe Supports

In the beginning of this discussion we talked about var ious types of pi pe suppor ts. Here is

some elaboration

There are three general types

1. R igid type (no f lexi bility in the direction of restrain)

2. Spr ing type (A

llows pi pe mov

ement in direction of loading)

3. Dynamic Suppor t (Degree of restrain depends on acceleration of load)

There are two types of spr ing suppor t

1.Var iable load type, here suppor t load changes as the pi pe moves.



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2. Constant load suppor t, the load remains constant within some range of

movement.

Some Special Considerations for Piping

When pi pes are routed UNDER GROUND (Bur ied) following points to

be kept in mind:

Minimum pi pe size to be routed under ground shall be not less than1

inch.

Avoid f lange joint in U/G pi ping.

K eep in mind if pi pe leaks U/G, it will be diff icult to detect, so avoid

U/G routing of pi pe carrying hazardous f luid.



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Pipe to be laid below Frost Zone at areas where ambient temperature

goes below freezing.

U/G, Buried piping should be properly protected from corrosion.

Pipe may be properly wrapped and coated to prevent corrosion.

Or U/G piping be protected by using Cathodic protection.

Freeze Protection of outdoor Piping:

In the areas where the ambient temperature goes below freezing there

is a possibility that the liquid content of pipe may freeze while the

plant is under shut down.

For similar case pipes are wrapped with heat tracing elements to

maintain the content temperature above freezing (around 4 deg. C)

even when the ambient temp. is below freezing.

Electric Heat tracing is done by wrapping electric coil around pipe,

which turns on as the ambient temperature goes down. Pipes are

insulated over the heat tracing coils.

Heat tracing can also be done by winding Steam tubes around main

pipes.



Causes of Serious Incidents

piping types and systems a brief surway

Documents