submersible pumps and motors for water well and offshore service

Previous Issue: 30 June 2002 Next Planned Update: 1 July 2007 Revised paragraphs are indicated in the right margin of 12 Primary contact: Hussain A. Al-Hazza on 874-7873

Materials System Specification

31-SAMSS-010 31 August 2005 Submersible Pumps and Motors for Water Well and Offshore Service Pumps, Seals & Mixers Standards Committee Members Al-Hazza, H.A., Chairman Al-Odan, N.M., Vice Chairman Al-Abbad, H.A. Al-Dolah, M.I. Al-Dossary, N.A. Al-Enazi, F.H. Al-Hussain, K.M. Al-Jamea, K.H. Al-Janbi, S.H. Al-Muqahwi, S.S. Al-Rabaa, S.A. Al-Shuhail, Y.S. Nguyen, L.V. Perez, E.C.

Saudi Aramco DeskTop Standards Table of Contents 1 Scope............................................................ 2 2 Conflicts and Deviations............................... 2 3 References.................................................... 2 4 Qualification Requirements........................... 3 5 Alternative Designs....................................... 3 6 Motor Basic Design....................................... 3 7 Pump Basic Design....................................... 5 8 Materials....................................................... 7 9 Inspection, Testing and Preparation for Shipment............................................... 9

Document Responsibility: Pumps, Seals & Mixers 31-SAMSS-010 Issue Date: 31 August 2005 Submersible Pumps and Motors Next Planned Update: 1 July 2007 for Water Well and Offshore Service

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1 Scope

This Specification, together with the submersible pump and motor Data Sheet (6880-ENG or 6880-M-ENG) and Purchase Order, covers the minimum requirements for bowl type submersible pumps and electric motors. Pump sections in utility water well service having a motor nameplate rating of 75 kW (100 HP) or less are excluded from this Specification. All motors, regardless of size, are covered by this Specification.

2 Conflicts and Deviations

2.1 Any conflicts between this Specification and other applicable Saudi Aramco Materials System Specifications (SAMSSs), Engineering Standards (SAESs), Standard Drawings (SASDs) or industry standards, codes and forms shall be resolved in writing by the Company or Buyer Representative through the Manager, Consulting Services Department, Saudi Aramco, Dhahran.

2.2 Direct all requests to deviate from this Specification to the Company or Buyer Representative, who shall follow internal company waiver procedures and forward such requests to the Manager, Consulting Services Department, Saudi Aramco, Dhahran.

3 References

Material or equipment supplied to this Specification shall comply with the latest edition (unless an edition is specified) of the specific references listed below or in the body of this document.

3.1 Saudi Aramco References

Saudi Aramco Inspection Requirements

Form 175-310900 Submersible Pumps and Motors for Water Well and Offshore Service

3.2 Industry Codes and Standards

American Society of Mechanical Engineers

ASME B1.1 Unified Inch Screw Threads

ASME B1.13M Metric Screw Threads - M Profile

ASME SEC VIII D1 Rules for Construction of Pressure Vessels

ASME SEC IX Qualification Standard for Welding and Brazing Procedures


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Acoustical Society of America

ASA S2.19 Mechanical Vibration - Balance Quality of Rotating Rigid Bodies. Part 1: Determination of Permissible Residual Unbalance

American Society of Non-Destructive Testing

ASNT SNT-TC-1A Recommended Practice for Qualification and Certification of Non-Destructive Testing Personnel

National Fire Protection Association

NFPA 20 Centrifugal Fire Pumps

4 Qualification Requirements

4.1 Submersible pumping equipment shall be supplied by Vendors qualified by experience in manufacturing the units proposed. To qualify, the Vendor must have manufactured, at the proposed manufacturing location, at least two machines of comparable size. These machines must have been in service for at least one year and must be performing satisfactorily.

4.2 Where experience with the proposed pump/motor combination does not exist, service of individual design features and of individual components may be demonstrated on several other operating machines. To qualify, each of these machines must have been in service for at least one year and must be performing satisfactorily.

4.3 In the area of component design, the Vendor must provide evidence that each component has operated under the same conditions as those of the proposed machines. The Vendor shall not quote any prototype models.

4.4 If applicable, the Vendor shall provide details of programmed or expected timing of obsolescence of the units and their spare parts.

5 Alternative Designs

All deviations from the Specification shall be separately listed by the Vendor in his Quotation and shall refer to the relevant paragraph numbers.

6 Motor Basic Design

6.1 General

6.1.1 For both onshore and offshore services where the pumped liquid


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temperature does not exceed 40°C, either oil filled or water filled motors may be used. For pumped liquid temperatures exceeding 40°C, oil filled motors shall be used.

6.1.2 Submersible motors shall be provided with a pressure equalizing system or an external oil/water circulating system.

6.1.3 Oil filled motors shall have forced oil circulation. Thermo-syphonic circulation is acceptable for water filled motors.

6.1.4 For open sump applications, submersible motors shall be provided with a shroud to ensure a minimum cooling flow velocity of 0.5 m/s (1.65 ft/s) over the motor outer casing.

6.1.5 For submersible motors in slop oil service, suitable cable for constant immersion in hydrocarbon liquid shall be used. Alternatively, conventional submersible power cable may be used provided that the cable is protected from the hydrocarbon liquid. The proposed method shall be submitted through the Company or Buyer Representative for review and approval by the Pumps' Standards Committee Chairman.

6.1.6 Submersible motor windings shall be adequately braced to permit the re-application of the rated voltage across the windings with a minimum of 33% residual voltage.

6.1.7 The winding insulation of water filled motors shall be Class Y and oil filled motors shall be at least equivalent to Class F.

6.2 Rotors

Rotors shall be machined and properly finished over their entire length. The total indicated runout of the bearing journal areas and the area under the coupling hub shall not exceed 25 micrometers (0.001 in). All other areas shall not exceed 50 micrometers (0.002 in) total indicated runout.

Exception:

The requirements of this paragraph are not applicable to long, flexible rotor motors which employ intermediate radial steady bearings along the rotor.

6.3 Bearings

6.3.1 Radial bearings shall be of the sleeve type. Use of Anti-friction bearings requires prior written approval of the Pumps' Standards Committee Chairman.


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6.3.2 Thrust bearings shall be of the tilting pad or solid shoe type and shall be rated to accept 200% of the maximum downthrust developed over the pump operating range from minimum continuous flow to end of curve flow. Pump starting upthrust, if any, shall be absorbed by the thust bearing or by a thrust button in the motor. Anti-friction bearings require the prior written approval of the Pumps' Standards Committee Chairman. The thrust bearing rating shall be based on the masses of the pump and motor rotors plus the coupling mass plus the maximum pump hydraulic thrust. The maximum pump hydraulic thrust shall be established from calculations which include thrusts developed during starting, stopping and while operating at any capacity, including zero flow.

6.4 Sealing

Submersible motors shall be provided with mechanical seals. Mercury seals and lip seals are not permitted.

6.5 Dynamics

Rotors shall be dynamically balanced.

6.6 Couplings

Couplings shall be of a rigid design and may be of the splined, claw or axially split types.

7 Pump Basic Design

7.1 General

7.1.1 The guaranteed pump performance curve, as quoted, shall be continuously rising to shut-off. The percentage head rise from rated head to shut-off shall not be less than 10%.

7.1.2 The rated capacity shall not exceed 110% of the capacity at the best efficiency point and shall not be less than 80% of the best efficiency capacity. The capacity at the end of the curve shall not be less than 125% of the best efficiency capacity and the minimum continuous stable capacity shall not be less than 50% of the rated capacity.

7.1.3 If the pump fails to meet the specified performance on site while handling the specified liquid at the conditions stated on the Data Sheet, the Vendor shall be responsible for performing any corrective action required.


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7.1.4 Performance of firewater pumps shall comply with NFPA 20. The pump absorbed power curve shall be non-overloading. Firewater pumps do not require UL/FM listing.

7.1.5 Design modifications to the pump bowls or internals which may affect the hydraulic or mechanical performance are not permitted after order placement, unless approved in writing by the Pumps' Standards Committee Chairman.

7.2 Bowls

7.2.1 The thickness of all cast bowls shall be suitable for the maximum discharge pressure plus allowances for head increases at pumping temperature and hydrostatic test pressure at ambient temperature with a 3.2 mm minimum corrosion allowance. The stress used in the design of any given material shall not exceed the values given in Section VIII, Division of the ASME Boiler and Pressure Vessel Code for the same material. For cast materials, a quality factor of 90% shall be applied as per ASME SEC VIII D1, UG-2.4.

7.2.2 Bowls having diameters of 300 mm and larger shall have flanged joints. If threaded bowls are used for diameters smaller than 300 mm, sealing shall be achieved by means of "O" rings in the partition grooves.

7.3 Miscellaneous Connections

Welding bosses shall be a minimum of 3,000 lbs rating.

7.4 Rotating Elements

7.4.1 Collet mounted impellers are acceptable if the absorbed power per stage does not exceed 56 kW (75 HP), above which power, keyed impellers shall be provided. The use of snap rings as a means of preventing axial movement of impellers requires the prior written approval of the Pumps' Standards Committee Chairman.

7.4.2 Shafts shall be machined and properly finished over their entire length so that there is no more than 40 micrometers total indicated runout per meter of shaft length.

7.4.3 Underfiling, overfiling or V-cutting, other than design standard, of impeller vanes to meet rated performance is not permitted unless approved in advance by the Pumps' Standards Committee Chairman. If approved, the Vendor shall submit a drawing showing details of the impeller outlet modifications. This drawing shall also be included in the Operating and Maintenance Manual.


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7.5 Wear Rings

7.5.1 Renewable bowl wear rings shall be provided.

7.5.2 Wear rings shall be held in place by means of a press fit with locking pins or threaded dowels (axial or radial) or by flanged and screwed methods.

7.6 Running Clearances

When establishing running clearances between wear rings or between other rotating and stationary parts, consideration shall be given to pumping temperature, suction conditions, the characteristics of the pumped liquid, the expansion and galling characteristics of the materials and the hydraulic efficiency. Clearances shall be sufficient to ensure dependability of operation and freedom from seizure under all operating conditions.

7.7 Bearings

7.7.1 Radial bearings shall be of the sleeve type.

7.7.2 Rotor masses and hydraulic thrusts shall be absorbed by a thrust bearing located in the motor. Submersible pumps having thrust bearings require the prior written approval of the Pumps' Standards Committee Chairman.

7.8 Dynamics

7.8.1 Actual critical speeds shall not encroach upon operating speeds. The amplification factor shall not exceed 8 while accelerating through critical speeds.

7.8.2 The first critical speed in the pumped liquid shall not be in the range of 85% to 125% of the specified operating speed.

7.8.3 Rotating elements shall be dynamically balanced where possible. Impellers having diameters of 152 mm and larger shall be balanced according to Grade G2.5 of ASA S2.19 or better.

8 Materials

8.1 General

The materials of construction shall be as specified on the Submersible Pump and Motor Data Sheet (6880-ENG and 6880-M-ENG). Equivalent materials complying with other national standards are acceptable provided that their physical and chemical properties are equivalent to or exceed those of the


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specified materials. Substitute materials shall be submitted through the Company or Buyer Representative for review and approval by the Pumps' Standards Committee Chairman. Gasket or packing materials containing asbestos are not permitted.

8.2 Castings

Castings shall not be repaired by means of peening, plugging, burning in, impregnation or by the use of plastic or cement compounds. Steel castings may be weld repaired.

8.3 Weld Repairs

8.3.1 All weld repairs including post weld heat treatment shall conform to the original material specification of the casting. All welding procedure specifications, performance qualification records and weld map documents must be available for the purchaser inspector review upon his request.

Welders shall be qualified in accordance with the requirements of ASME Section IX.

Weld repairs of pressure containing castings, including impellers shall be considered major if any of the following conditions apply:

a. Castings leak during hydrostatic testing;

b. The depth of the repair cavity prepared for welding exceeds 20% of the wall thickness or 25 mm, whichever is smaller;

c. The surface area of the repair cavity exceeds 65 cm²;

8.3.2 All major repairs shall be documented. The documentation shall include the following:

a. Extent of the repair

b. Location

c. Size

d. The welding procedure specification

e. Detailed photographs of the defect:

1) Prior to any preparatory work.

2) After preparation but prior to the actual repair.

If the location of the defect cannot be clearly defined by photographic means, the location shall be indicated on a sketch or drawing of the


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affected component.

8.3.3 The Purchaser may require additional non-destructive examinations to verify the acceptability of the repair. Such additional requirements will then be subject to mutual agreement between the Purchaser and the Vendor.

8.4 Material Inspection

Steel impellers shall be subjected to a liquid penetrant examination or a wet fluorescent magnetic particle examination if the peripheral velocity of the impeller, at operating speed, is 45 m/s (150 ft/s) or higher. All visible surfaces of the impeller (prior to wear ring installation) shall be examined and shall be in agreement with the criteria set forth in the ASME SEC VIII D1, Appendices 6 and 8. All non-destructive examinations shall be performed by personnel certified in accordance with ASNT SNT-TC-1A. Certification in accordance with equivalent National Certification Programs are acceptable, subject to review and approval by the Manager, Saudi Aramco Inspection Department.

8.5 Miscellaneous

8.5.1 The details of threading shall comply with ASME B1.1 / ASME B1.13M or other internationally standardized threading.

8.5.2 All equipment shall be designed to permit rapid and economical maintenance. Major components shall be shouldered or doweled to ensure accurate alignment on assembly.

8.5.3 The pump and motor shall be supplied with all special tools necessary for dismantling and assembling the units.

8.5.4 Pump and motor nameplates of 18Cr-8Ni stainless steel or Monel shall be provided, securely attached to the surface plate assembly by means of fasteners of the same material.

9 Inspection, Testing and Preparation for Shipment

9.1 Inspection

Inspection shall be in accordance with the referenced Form 175-310900.

9.2 Testing

9.2.1 Tests shall be performed and witnessed or observed as indicated on the referenced Form 175-310900.


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9.2.2 Each motor shall be given a routine test to demonstrate that it is free from mechanical and electrical defects. This test shall include the following:

a. A high potential test on the stator.

b. An insulation resistance test.

c. Measurement of the winding resistance.

d. Measurement of the no-load current (each phase).

e. A determination of the locked rotor current.

9.2.3 Curves showing motor efficiency and power factor at 100%, 75% and 50% of full load shall be provided. The Vendor shall indicate which test code method will be used in the determination of this performance data.

9.2.4 For oil filled motors, a polarization index test shall be conducted. The polarization index shall not be less than 2.0.

9.2.5 Pump bowl assemblies shall be hydrostatically tested, using water at ambient temperature, to a pressure of 1.5 times the maximum allowable bowl assembly pressure.

9.2.6 Performance testing shall be at rated speed. If this is not feasible due to power or supply frequency limitations, an alternative procedure shall be submitted through the Company or Buyer Representative for review and approval by the Pumps' Standards Committee Chairman.

9.2.7 Test measurements shall be taken at shut-off, minimum continuous stable capacity, mid-way between minimum continuous stable capacity and rated capacity, rated capacity and 120% of rated capacity. Firewater pumps shall be tested out to 150% of rated capacity.

9.2.8 The pump test performance characteristics shall not deviate from the quoted performance characteristics by more than the following tolerances:

Condition Rate Point (%) Shutoff (%)

Differential Head 0-150 m (0-500 ft)

-2 +5

+10 -10 See Note

151-300 m (501-1000 ft)

-2 +3

+8 -8 See Note

Over 300 m (1000 ft)

-2 +2

+5 -5 See Note

Rated Power +4 Note: The negative head tolerance is permissible only if the test curve shows a constant rise from

the rated point to shut-off.


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9.2.9 On completion of performance testing, the pumpset shall be set at its rated point and run for a continuous period of not less than one hour. Test measurements shall be taken at fifteen minute intervals during this period.

9.3 Preparation for Shipment

9.3.1 Equipment shall be suitably prepared for the type of shipment specified, including restraint of rotors when necessary. Restrained rotors shall be identified by means of corrosion resistant tags attached with stainless steel wire. The preparation shall make the equipment suitable for six months of outdoor storage from the time of shipment, with no disassembly required before operation, except for inspection of motor seals.

9.3.2 The Vendor shall provide any instructions necessary to preserve the integrity of the storage preparation after the equipment arrives at the job site and before start-up.

9.3.3 The equipment shall be prepared for shipment after all testing and inspection has been completed and the equipment has been released by the Buyer.

9.3.4 Unless otherwise specified, pumps shall not be disassembled after performance testing with acceptable test results, provided that the pump is completely drained and dried and suitable rust preventative is applied for all internal parts. The rust preventative shall be applied within four hours of completion of testing.

9.3.5 Flanged openings shall be provided with metal closures at least 5 mm thick with elastomeric gaskets and at least four full diameter bolts. For studded openings, all nuts required for the intended service shall be used to secure the enclosures.

9.3.6 Threaded openings shall be provided with stainless steel plugs.

9.3.7 The equipment shall be identified with item and serial numbers. Material shipped separately shall be identified with securely fixed, corrosion resistant metal tags indicating the item and serial number of the equipment for which it is intended. In addition, crated equipment shall be shipped with duplicate packing lists, one inside and one on the outside of the shipping container.

9.3.8 Exposed shafts and shaft couplings shall be wrapped with waterproof, moldable waxed cloth or volatile corrosion inhibitor paper. The seams


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shall be sealed with oil proof adhesive tape.

One copy of the manufacturer's standard installation instructions shall be packed and shipped with the equipment.

Revision Summary 30 June 2002 Revised the "Next Planned Update". Reaffirmed the contents of the documents, and

reissued with minor changes. 31 August 2005 Minor revision for clarifications, minimize cross referencing be inline with other pump

specification and accept internationally standardized threading.

submersible pumps and motors for water well and offshore service

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