TABLE OF CONTENTS

1.0 Scope

2.0 General Pump Selection

3.0 Pump Specification

4.0 Paint Specification

5.0 Quotation Requirements

6.0 Documentation Requirements

7.0 Vendor Requirements

8.0 Mechanical Seal Specification

This specification applies to the selection and performance of commercially available centrifugal pumps for use in Naval Services. The intent of this specification is that the supplied equipment shall be designed to meet MIL SPEC 901D and MIL STD-167 and offer long service life, minimize life cycle costs and be easily installed and maintained.

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2.0 PUMP SELECTION

2.1.1
The general pumps for new ship construction shall be selected to allow maximum interchangeability of parts without limiting pump performance. The rotating assembly/power end for each pump shall be interchangeable with all the pump wet ends selected (within the model class), unless otherwise designated.

2.1.2
The pumps shall operate in accordance with the required hydraulic performance requirements determined by the specific application.

2.1.3
The pump shall operate smoothly throughout the entire design operating flow range at the specified RPM with low vibrations. Acceptable vibration limits for the pump are specified in Hydraulic Institute Standards for centrifugal pumps.

2.1.4
The pump impeller shall provide the design head and flow rate as designated by purchaser. The impeller diameter selected to meet design conditions shall not be smaller than the minimum as shown in the manufacturers published performance curves.

2.1.5
The pumps defined herein are for general Naval service. They shall be designed for 24 hours/day, 7 days/week operation. It is the intent of this specification to define continuous duty pumps that meet MIL SPEC 901D and MIL STD-167 and are designed for maximum performance life with low maintenance and operations costs.

2.1.6
The pump shall be a back pull-out design with a radially split casing.

2.1.7
The noise level generated by the pump and motor shall not exceed 85 dB, or motor noise level plus 3 dB, when measured at a distance of 3 feet.

2.2.0
The pump suction and discharge flange arrangement shall conform to ANSI B73.1 standard.

2.2.1
Castings shall be sound and free of shrink holes, blow holes, scale, blisters and other obvious defects.

2.2.2
Pressure containing castings shall not be repaired by plugging, peening, burning in or impregnating.

2.2.3
The pump shall be permanently tagged with a 300 series Stainless Steel nameplate. Nameplate information shall include pump size, GPM, TDH, speed, material of construction, impeller diameter (max. and rated) and serial number. An arrow shall also appear on the pump showing rotation direction.

2.2.4
Casing discharge shall be centerline discharge unless otherwise specified.

2.2.5
Pump shall be selected based on minimizing life cycle costs and emissions and not on minimizing initial purchase costs. Proposed selection will be based on rotor dynamics evaluation (shaft stiffness ratio) , hydraulic performance and effective window of operation. Debits/credits will be used to evaluate vendor proposals.

2.2.6
The pump casing shall incorporate centerline support feet for design temperatures above 250o F. on medium and large frame pumps.

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3.0 PUMP SPECIFICATION

The pump unit shall be horizontal end suction or vertical with an in-line suction adapter, in accordance with the following specification:

3.1.1 CASING
The pump casing shall be constructed of CD4MCu or material as required by the application. The casing for the pump sizes below 4x6-13 (ANSI designation A80) shall be single volute design, with the discharge flange located on the vertical centerline of the casing, and meet ANSI B73.1 specifications and dimensions. For all sizes above A80, double volute construction is required.

The casing for medium and large frame pumps will be equipped with centerline mounted feet for high temperature applications (above 250 deg. F). The feet support the pump casing utilizing two (2) separate legs made of ductile iron or carbon steel, which will prevent misalignment of the pump rotating element within the pump casing at elevated temperatures. This feature allows the casing to adapt to thermal cycles and significantly reduce stresses which would result in misalignment of rotary and stationary components as well as premature failure of components, ie. bearings and mechanical seals.

The casing suction and discharge nozzles shall be 150 lbs. or 300 lbs., FF (flat face) as required by the application. The casing shall be capable of accepting full API 610 suction and discharge nozzle loading.

The suction and discharge neck will be drilled and tapped with ¼" NPT connections, for pressure gauges and/or auxiliary piping. The casing wall thickness will include 1/8" corrosion allowance. A rotation arrow will be cast on the surface of the casing to indicate the proper direction of rotation.

3.1.2 IMPELLER
The impeller shall be open type, cast in CD4MCu or material as required by the application. Investment cast impellers are preferred. Repelling vanes shall be cast on the back side of the impeller, to reduce the pressure behind the impeller in the immediate area of the mechanical seal and seal chamber.

The impeller hubs shall incorporate a threaded fit to the pump shaft. An optional locking device can be applied for pumps which can potentially operate in the reverse direction. The impeller threads shall be sealed from corrosive environment by a Teflon O-Ring in the hub.

Enclosed impellers for ANSI sizes below A80 are not acceptable.

The impeller shall be balanced to ISO specification G.6.3 or better unless otherwise specified. Balancing will be performed in a minimum of two planes. Balancing shall, unless detrimental to the component or its performance, be attained by the removal of material. Impeller balancing is critical to minimizing vibration and prolonging pump life.

3.1.3 SHAFT
The pump shaft shall be constructed of 316SS or material as required by the application. Shaft sleeves are not acceptable . The pump shaft shall be mechanically non-contacting throughout the entire rotating element, with the exception of the ball bearings, to prevent wear at the bearing oil seals, and mechanical seal.

The shaft stiffness ratio, L3/D4, (where L= length of shaft from impeller centerline to nearest bearing in inches, and D= shaft diameter under the seal in inches), shall not exceed the following values in order to establish satisfactory bearing and mechanical seal life, minimize vibration, and maximize equipment reliability.

Centrifugal Pumps are designed with single volute casings that develop radial forces when operated away from the "best efficiency point". The further the pump is operated from the BEP the higher the radial forces. As these loads are applied to the pump rotor system, they cause the shaft to deflect when operated off BEP. The magnitude of the deflection is directly related to the magnitude of the force. The pump will also experience higher vibration frequencies as a result of the impeller vanes passing the cut water.

Operating the equipment off BEP will cause premature mechanical seal failure, bearing failure and damage to other pump components.

Pumps that are designed with stiffer shafts can effectively resist these forces. The industry standard that is used in benchmarking rotor stiffness is commonly referred to as shaft stiffness ratio L3/D4 and equipment which is designed with low values offer superior performance, life and reliability under the most severe operating conditions.

3.1.4 THRUST AND RADIAL BEARINGS
The Pumps shall be fitted with the following minimum bearing sizes:

Small Frame Pumps (sizes 1x1.5-6, 2x3-6, 1x1.5-8, 1.5x3-8);

• Thrust bearing shall be 5308 AHC3 clearance, double row, deep groove
• Radial bearing shall be 6308. C3 clearance, single row, deep groove

Mid Frame pumps (sizes 1x2-10, 1.5x3-10, 2x3-8 thru 4x6-13);

• Thrust bearing shall be 7310 BEGAY , qty 2, back-to-back angular contact;
• Radial bearing shall be 6310 C3 clearance, single row, deep groove

Large-Frame Pumps; (sizes 6x8-13 thru 8x10-15);

• Thrust bearing shall be 7314 BEGAY, qty 2, back-to-back angular contact
• The radial bearing shall be 6314, C3 clearance, single row, deep groove

The thrust and radial bearings will be fitted to the shaft based on SKF tolerance specifications. The method of lubrication shall be oil bath for horizontal pumps and grease for vertical pumps. The thrust bearing shall be locked into the cartridge by a bolted-on retainer cover; a snap ring thrust bearing retainer is not acceptable.

The radial bearing shall be permitted to slide within the inside diameter of the bearing frame to prevent axial load and permit radial load only. Double row filled slot bearings are not acceptable. Bearings shall be designed for a minimum L-10 life of 60,000 hours.

3.1.5 BEARING FRAME
The bearing frame shall be heavy-duty construction, cast iron with radial fins for maximum cooling. The oil sump shall contain a minimum of 8 ounces of oil for small frame pumps, 32 ounces for mid-frames and 42 ounces of oil for large frames to allow for more heat dissipation, better lubrication and a cooler running rotating element.

The oil level within the bearing frame shall be monitored by an oil sight glass. The level shall not exceed the bearing lower ball centerline for both the thrust and radial bearings in order to provide ample lubrication and heat dissipation.The oil sight glass shall have a white color perforated background, to permit visual inspection of the condition of the oil and also permit circulation of oil in the sight glass to keep the interior surface of the glass clean.

An oil drain plug is required at the bottom of the bearing frame. Two (2) magnetic pipe plugs shall be located near the bottom of the bearing frame. The oil fill fitting at the top shall be nylon material with an easily removable cap for adding oil. Trico or bottle type constant level oilers are not acceptable.

3.1.6 BEARING OIL SEALS
Each end of the bearing frame assembly shall incorporate non-contacting (non-wearing) labyrinth oil seals. This type of seal is required to eliminate shaft damage due to friction and heat from the contact type lip seals. The materials of construction shall be nickel-plated steel stationary with a 316SS rotor. The Labyrinth Seal shall prevent water, dirt and other contaminants from entering the bearing housing in order to maximize bearing life.

Lip seals are not acceptable.

Face type oil seals are to be available for severe applications as required.

3.1.7 FRAME ADAPTER
The frame adapter shall be designed to maintain accurate alignment of the bearing frame and rotating element to the wet end. Also, allow proper access to the mechanical seal and environmental seal control piping.

3.2.0 BACK COVER and MECHANICAL SEAL CHAMBER
The back cover and seal chamber shall be of CD4MCu or other material as required by the application, with a corrosion allowance of 1/8". The back cover shall be sealed to the pump casing with a confined type of gasket that is impervious to the fluid pumped.

The back cover shall incorporate a large bore seal chamber. The seal chamber shall be designed with a minimum radial clearance between the box inside bore and shaft O.D. of at least .75" on small and mid-frame pumps and 1 3/8" on large frame pumps. This will result in improved cooling, cleaning, lubrication and circulation to prolong the life of the mechanical seal.

The chamber shall have an optional tangential flush connection on the side to flush the mechanical seal, and provide maximum cleaning capability. The seal chamber shall be capable of incorporating a jacket (when required) for cooling on high temperature applications or steam heating for liquids that tend to congeal in the seal chamber. Open taper bore seal chambers in abrasive applications are not acceptable.

3.2.1 CENTERLINE SUPPORT LEGS
All mid-frame and large frame pumps operating above 250 deg. F shall be supplied with keyed (to casing ) centerline casing support legs.

3.2.2 IMPELLER CLEARANCE ADJUSTMENT
The thrust bearing end of the bearing frame shall be capable of precision (.003" minimum delineation) impeller adjustment, to permit clearance adjustment without the use of shims, dial indicators, feeler gauges and/or without having to take the pump apart. The foregoing is to permit ease of adjustment and maintain high pump efficiency by simple readjustment after the pump has been in service for a long period of time.

3.2.3 BACK PULLOUT FEATURE
The pump shall incorporate the back pullout feature, which permits the removal of the entire bearing frame assembly, including shaft, mechanical seal and impeller, without disturbing the pump discharge and suction piping and without disturbing the motor.

3.2.4 C - FRAME MOTOR ADAPTER
The pump shall incorporate a C-frame motor adapter, which permits mounting of motors up to 447 TC frame, without the need conventional parallel and angular alignment. The C-frame shall be equipped with feet capable of meeting the requirements of MIL-SPEC-901D.

The C-Frame motor adapter shall provide accurate motor shaft to pump shaft alignment, without the need for timely manual alignment procedures. Accurate alignment is necessary for improved mechanical seal and bearing life as well as minimizing vibration.

3.2.5 WARRANTY
The pump shall be warranted for a period of one (1) year from the date of installation, but not to exceed eighteen (18) months after the date of shipment to the user, to be free of defects in material and workmanship. In addition, the pump vendor shall include the following pump warranty:

PUMP WARRANTY

1. A lifetime warranty on the small and mid frame shafts ( shafts under 1.88 " dia. at the seal) against breakage or fretting damage due to the mechanical seal. Non-fretting sealing devices must be used. This warranty protection does not cover chemical corrosion or erosion, normal wear, damaged keyway slots or faulty assembly/disassembly procedures.
   This warranty is limited to one replacement shaft per pump.
2. A five year warranty on the pump power end assembly including bearings.
3. The mechanical seal shall be warranted for a minimum one year period. An exchange seal or spare parts kit will be provided if there is a seal failure.

These warranties will exclude coverage for erosion or corrosion.

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4.0 PUMP PAINT SPECIFICATION

Surface preparation:

Parts are cleaned in an industrial washer with Chesterton KPC 820 cleaner.

All parts are then rinsed in a rinse tank.

Paint:

One coat of Rustoleum "High Performance Epoxy 9100 Series System" Yellow #A91-4412 base with A5275 activator.

This product is a two component, high build, polyamide / amine-modified low VOC epoxy coating.

Total Paint Thickness:

Dry film thickness range of epoxy coating shall be .005" to .008".

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5.0 QUOTATION REQUIREMENTS

5.1.1.
Quotation shall be completed in strict accordance with the requisition, Data Sheets, vendor information requirements, applicable codes and this specification.
5.1.2
Vendor shall state all exceptions to this specification in the bid package. All deviations and/or exceptions from this specification and/or data sheets must be outlined in full detail and the reasons for them in the quotation.

5.1.3
Unless the vendor proposal takes exception to the purchasers bid documents (specification, data sheets, inquiry, purchase requisition, etc.), conformance is implied and assumed. Alternates and exceptions shall be clearly described and defined in the vendor's proposal.

5.1.4
Alternates may be submitted with the bid. They shall be clearly described and defined in the vendor's proposal.

5.1.5
The proposal shall include a Pump Performance Curve showing GPM, TDH, NPSHR, Efficiency, Power requirements @ design and at max flow, and design and maximum/minimum impeller diameters. Also included shall be shaft stiffness ratios and descriptive literature for the pump and the mechanical seal.

5.1.6
The quotation shall include a complete list of recommended spare parts with price and delivery information.

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6.0 DOCUMENTATION REQUIREMENTS

After the purchase order is received, the seller shall furnish the following:

1. Dimensional Print--5 Copies
2. Parts List with Recommended Spares--5 Copies
3. Operations and Installation Manual--5 Copies
4. Certified Performance Curves--5 Copies
5. Mechanical Seal Drawings--5 Copies

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7.0 VENDOR REQUIREMENTS

The vendor shall have the capability of providing spare parts to any location within a 24 hour period. All applicable spare parts must be available from the plant within this time period. Service capabilities will include start-up, troubleshooting and personnel training by the vendor authorized representative.

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8.0 MECHANICAL SEAL REQUIREMENTS

1. General

1. The seal shall be:

• Balanced, single, inside, cartridge mounted, stationary or rotary type with o-ring configuration elastomers.
• Guaranteed not to fret a shaft when properly installed.
• Able to fit into a 3/8" cross section stuffing box for shaft diameters 1" to 2 ½" and into a ½" cross section for shaft diameter sizes 2 5'8" to 4".
• Vacuum tested to check for leaks prior to shipment.
• Affixed to the pump shaft by set screw.
• Equipped with removable centering clips to allow for proper centering and spring compression during installation.

2. The stationary or both rotary and stationary seal faces shall be multiple spring loaded to provide self-aligning. The springs must be isolated
   from the pumped product.
3. The gland shall be 316 stainless steel with built in quench port, drain port, and tangential flush ports. The ports may be either ¼", 3/8", or ½" NPT.
4. A floating throttle bushing is required in the gland and must be a non-sparking material such as carbon or bronze.
5. The gland shall have four slotted holes for mounting to the stuffing box face.
6. The seal must be designed to allow the dynamic o-rings to move toward a clean surface as the rotary face wears.

2. Material of Construction

1. All metal components (except springs) shall be 316 or 316L stainless steel.
2. Springs to be Hastelloy C (Cabot Corporation Trade Mark).
3. Rotary Seal Face:

• Pure 658RC Carbon as standard

Options

• Nickel Based Solid Tungsten Carbide
• Solid Silicon Carbide

4. Stationary Seal Face:

• Nickel Based Solid Tungsten Carbide as standard

Options

• Solid Silicon Carbide

5. Throttle Bushing (Non-Sparking):

• Carbon
• Bronze
• Support metal parts to be 300 stainless steel

6. Face combinations are to be selected based on specific application conditions and seal size. Consult seal manufacturer for recommendations if necessary.

3. Acceptable Seals

1. Models 123 and 180 as manufactured by the A. W. Chesterton Company, Stoneham, Mass

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