Section 6 — Rotating Equipment

Reciprocating Compressors

IPE Engineering Practice IPE-EP-6-2-1

Document number: IPE-EP-6-2-1 · Section: 6 — Rotating Equipment

The following paragraph numbers refer to API 618, Fourth Edition, June1995, which is part of this Engineering Practice.

INTRODUCTION

requirements for reciprocating compressors correspond to those of API Standard 618, Fourth Edition, June 1995, with the specific options, deletions, additions, or modifications sanctioned in this Practice.

The paragraph numbers in this specification correspond to those used in API 618. Paragraph numbers may not be consecutive and all API 618 paragraphs not mentioned herein shall be considered to be verbatim requirements of this specification.

Instructions contained in this specification such as "add" or "substitute" shall be interpreted as follows: If information is "added" to an existing paragraph in the API Standard, the requirements of this specification shall be read as a continuation of that particular API paragraph. If information is "substituted", the affected API requirement shall be replaced in its entirety by the requirements of this specification. If (new) is next to a paragraph number, not appearing in API 618, it shall be read as an added requirement.

The purchaser's requirements for all paragraphs in API 618 which require a purchaser's decision (bulleted paragraphs) are indicated on the data sheets or in this specification. If not addressed in the inquiry, the proposal shall clearly state the basis included in the pricing furnished.

Table 1 records the vendor drawing and data requirements.

NOTE: U.S. Customary units shall be regarded as standard. SI (metric) units in API 618 and this supplement are included for convenient reference only and shall not be interpreted as precise conversions.

GENERAL

• Scope

• (Add) This practice is a purchase specification when accompanied by the referenced Engineering Practices and the completed data sheets required by this practice. The vendor shall quote in strict accordance with the bid inquiry. Alternative bids are acceptable; however, deviations must be completely documented. All deviations from this Practice must be approved by the procedure described in EP 1-1-3.

• A revision bar indicates all changes made to this Revision.

• Alternative Designs

• (Add) Metric fasteners and flanges constitute alternative design features and must be cited as exceptions in the vendor proposal.

• Conflicting Requirements

• (Substitute) In case of conflict between the various documents, their order of precedence is generally as follows:

Purchase Order Data Sheets

Project Specification(s) Referenced Industry Standards

• (New) All conflicting requirements shall be referred to the purchaser in writing prior to issuance of the purchase orders. The purchaser will issue confirming documentation if needed for clarification.

• (New) Mandatory requirements cannot be superseded by any of the foregoing and compliance therefore will be the responsibility of the vendor. Mandatory requirements include all codes, regulations, ordinances, and statutes of all municipal, state and national bodies having jurisdiction in the locations where the equipment is to be installed. It shall be the vendor's responsibility for discernment and compliance with those mandatory requirements.

• Referenced Publications

• (Substitute) This paragraph of API 618 does not apply to this specification (See 1.3.3 above).

• (New) The referenced Engineering Practices, and any other attached to the requisition shall apply to the extent referenced herein or on the data sheets.

STANDARDS AND PUBLICATIONS

STANDARDS AND PUBLICATIONS (CONT.)

• (New) Coordination

•  Unless otherwise specified, the compressor vendor shall coordinate, expedite, and resolve any sub-vendor problems. The vendor shall also guarantee and be responsible for the design and satisfactory performance and operation of the complete unit, i.e. compressor, drivers, drive, instrumentation and all auxiliary equipment.

• The compressor vendor shall be responsible for ensuring that the designs of equipment for the total system regardless of source, are compatible with each other and with his own equipment, dimensionally and in performance and control, so that a fully integrated unit is achieved.

BASIC DESIGN

• General

• (Add) Compressor and drive train shall also be designed for continuous operation in any condition of loading and unloading that are achievable with the capacity control system provided at rated pressure to each stage.

• (Substitute) Compressor vendor shall be responsible for total train noise levels and shall meet the following:

• The maximum allowable noise level for each noise source shall be in accordance with the requirements of Engineering Services Recommended Environmental Guidelines.

• Where the equipment cannot meet the specified limits without the addition of a sound attenuating enclosure, the estimated levels with and without the enclosure, and the basis for the estimate, shall be stated in the proposal.

• If noise attenuation enclosures are required, the vendor shall furnish an enclosure approved by the Purchaser. The equipment shall be enclosed with instruments and piping connections on the outside of the enclosures. The enclosures shall have adequate provisions for servicing the equipment and for ventilation.

2.1.9 (Substitute) All equipment shall be designed to permit rapid and economical maintenance. Major parts such as the frame, cross-head support, distance pieces and cylinders shall be designed (shouldered or dowelled) and manufactured to ensure accurate alignment during reassembly.

2.1.14 (Modify) Omit the bullet.

(Add) Vendor shall recommend protective devices, in addition to those specified, which are deemed necessary to prevent damage to equipment.

• Allowable Speeds (Add)

The average piston speed shall not exceed 750 feet/min for non-lubricated compressors or 850 feet/ min. for lubricated compressors. The maximum shaft speed shall be 500 rpm.

Vertically-oriented labyrinth piston compressors shall be exempt from the 750 feet/min average piston speed limitation.

• Allowable Discharge Temperature

2.3.1 (Substitute for first sentence) The maximum actual discharge temperature shall not exceed the following values:

MAXIMUM DISCHARGE TEMPERATURE

2.4 Rod Loadings

2.4.6 (New) Actual rod loading for specified normal and worst-case conditions (i.e., at pressure relief valve set pressure or partial load) shall be submitted at the time of the proposal.

• Critical Speeds

• (Add) Vendor shall perform a torsional analysis of the complete drive train and submit a report of the results to the purchaser.

• Compressor Cylinders

• Cylinder Appurtenances

2.6.2.3 (Add) Liner shall extend the full length of the cylinder.

• Cylinder Cooling

2.6.3.3.a. (Add) For wet or saturated air or gas services, coolant inlet temperatures to the first stage shall be at least 15F higher but no more than 30 F higher, than the first-stage gas inlet temperatures.

2.6.3.5.1 (Add) For wet or saturated air or gas services, a means shall be provided to permit supplying cooling water to the cylinder jackets at an entering jacket temperature of at least 15F above the gas inlet temperature.

• Valves and Unloaders

• (New) For dirty gas applications, Manley valves or an approved equivalent shall be used.

• (New) Non-metallic valve plates/rings shall be used to the maximum extent possible in order to provide a maximum of corrosion protection and long operating life.

2.8 Pistons, Piston Rods, and Piston Rings

2.8.3 (Add) Plating of the piston is not an acceptable substitute for separable wear bands. Nonmetallic, one-piece wear bands, at least 1/2" thick, shall be provided and located near the center of the piston. The piston rings shall be located on the gas ends of the piston.

2.8.7 (New) Material for piston rings and wear bands shall be appropriate for the service and shall be selected from the ASME design manual titled, "PTFE Seals in Reciprocating Compressors". Alternatively, the vendor may offer high performance polymers such as Dupont "Vespel".

• Crankshafts, Connecting Rods, Bearings and Crossheads

2.9.9  (New) When specified, the vendor shall provide a crankcase purge connection for injection of a dry, inert gas by the Purchaser. This connection shall be in an accessible location at the maximum practical distance away from the crankcase breather.

• Distance Pieces

2.10.2  (Substitute for third sentence) For compressors equipped with two-compartment distance pieces, frame end shall be provided with louvered weather covers, and all cylinder ends shall be equipped with gasketed solid metal covers. Single-compartment distance pieces shall be equipped with louvered weather covers or gasketed solid metal covers as specified on the data sheets.

• Packing Cases and Pressure Packing

2.11.3 (Add) Piping and tubing inside the distance piece shall be corrosion resistant and designed for the maximum allowable working pressure of the cylinder.

2.11.8 (Add) For type C distance pieces, the vendor's proposal shall indicate gas-emission levels with and without buffer gas cups.

2.12 Compressor Frame Lubrication

2.12.1 (Add) If a splash system is used, it shall include an oil level indicator

2.12.6 (Add) Dual filters shall be used on compressors in continuous service.

2.12.9 (New) When an auxiliary pump is furnished or when coolers or filters are too large to be located within the confines of the compressor base; the pump, cooler(s), filter(s), instruments and interconnecting piping shall be mounted on a skid.

2.13 Cylinder and Packing Lubrication

2.13.9 (Add) The vendor shall recommend the best suited lubricant for the service and shall specifically comment on the merits of Diester Synthesized Hydrocarbons for cylinder lubrication in the specified compression service.

2.14 Materials

2.14.2 Castings and Forgings

2.14.2.5 (Add) All pressure-containing castings shall meet the requirements of ASME Section VIII, Division 1 Appendix 7, paragraphs 7.2 through 7.5. All welding shall be in accordance with the requirements of ASME Section IX.

2.14.3 Repairs and Welding

2.14.3.2 (Add) Improperly fused chaplets in iron casings may not be replaced with plugs. Iron castings with improperly fused chaplets shall not be accepted.

ACCESSORIES

• Drives

3.1.1 General

3.1.1.7 (New) Axial, lateral and vertical jackscrews shall be provided for foot mounted drivers and gearboxes mounted on the vendor furnished baseplates, soleplate, or rails.

3.1.2 Motor Drivers

3.1.2.5  (Substitute) The design of the motor shall conform to NFPA to NEMA MG 1 and EP 13-3-2 and/or EP 13-3-3, as specified.

• Turbine Drivers

•  (Add) Steam turbine drivers shall conform to EP 6-3-1 or EP 6-3-2, as specified.

•  (Substitute) When specified, a separate lube oil system in accordance with EP 6-9-1 shall be supplied

3.2 Couplings and Guards

3.2.1 Couplings

3.2.1.2 (Add) Tapered hydraulically fitted couplings are required if engine type motor mounting is not provided.

3.5 Mounting Plates

3.5.2.14 (Add) Stainless steel (AISI Standard Type 300) shim packs, 1/4 - 1/2 inch thick, between the pedestals, equipment feet, or frame and the soleplate shall be provided. Vertical and horizontal jackscrews for easy removal or additions of shims shall be provided by the vendor.

3.5.4 (New) Mounting pads upon which equipment feet rest shall be at least one inch wider in both horizontal directions in order to allow placement of a precision machinist level during equipment installation.

3.6 Controls and Instrumentation

3.6.1 General

3.6.1.2 (Add) Instrumentation and Installation shall be in accordance with EP 12-1-1 and EP 12-2-1.

• (Add) The vendor shall provide the following pressure and temperature gauges (in addition to the gauges specified on the data sheets) mounted locally or on a gauge board as specified on the data sheets.

• Oil pressure at each pressure relief valve and pressure switch.

• Gas temperature at the inlet to each stage and discharge of each cylinder when piping (pulsation dampers) is provided by the vendor.

• Gas pressure for the compressor inlet and discharge of each stage when interconnecting piping is furnished by the vendor.

• Inlet and outlet oil temperatures for oil coolers.

• Differential pressure across replaceable cartridge lubrication oil filters not built into the compressor frames.

• Inlet and outlet water temperatures for intercoolers and aftercoolers when coolers and/or water piping are supplied by the vendor.

• Control Systems

3.6.2.2  (Add) The vendor shall include in the proposal the extent of unloading required for startup, unless specified by Purchaser.

• Instrument and Control Panels

3.6.3.1 (Add) Wiring terminations for different voltages shall be housed in separate enclosures.

3.6.3.3 (Add) The vendor shall provide a tachometer located at the instrument panel, when a turbine drive is supplied.

• Instrumentation

• Temperature Measurement

• (Add) Mercury thermometers and mercury filled dial gauges shall not be used.

• Pressure Measurement

• (Revise) Delete the words "When specified" in the third sentence and the bullet at the beginning of the paragraph.

3.6.4.5 Relief Valves

3.6.4.5.1 Omit the bullet and words "when specified."

• Alarms and Shutdowns

3.6.5.2 (Add) Alarm and shutdown shall be initiated by separate switches.

• Electrical Systems

3.6.6.8 (Add) For Division 1 locations, conduits, fittings and junction boxes shall be explosion proof.

• Vibration and Position Detectors

3.6.7.2 Delete the bullet and the words "when specified."

• Piping and Appurtenances

3.7.1 General

3.7.1.5 (Add) The vendor shall clearly identify all piping requiring insulation, heat tracing, and personnel protection.

3.7.1.7 Omit the bullet and words "when specified."

(Add) Vendor shall clearly identify piping requiring heat tracing and/or insulation

3.7.1.19 (New) In the proposal, the vendor shall include allowable forces and moments on process customer connection points. These values may be used in the bid evaluation and shall be confirmed by the vendor after the order placement.

3.7.6.3 (Add) The vendor shall furnish a commercially available startup screen to be installed just upstream of each suction damper.

• Intercoolers and Aftercoolers

• (Revise the last sentence to read) When TEMA Class R is specified, the heat exchanger shall also be in accordance with APl Standard 660 and EP 8-1-1.

• (Add) Maximum baffle spacing shall be limited to 18 inches.

3.8.7 (Substitute) When air coolers are specified, they shall conform to APl Standard 661 and EP 8-1-4.

3.8.10 (Add) Intercoolers shall be installed downstream of' the discharge pulsation dampener, when the latter is installed.

• Pulsation and Vibration Control Requirements

• General

3.9.1.a (Add) Unless otherwise recommended by the vendor, suction and discharge volume bottles shall be furnished for each cylinder.

• Design Approaches

3.9.2.6 (Add) Acoustical evaluations for design approaches 2 and 3 shall be quoted separately by the vendor. All data required for a study shall be agreed upon at the Vendor Coordination Meeting and a schedule and coordination procedure shall also be established. A report of the study results shall be submitted to the Purchaser and shall be demonstrated to the Purchaser's satisfaction.

• Pulsation Suppression Devices

3.9.3.9  (Substitute) Unless otherwise specified by the Purchaser on the data sheets, the vendor shall state in the proposal the recommended volume bottle nozzle location and orientation options that are available, subject to practical limitations and dynamic design requirements. Ratings, types, and arrangements of all connections shall be agreed upon by the Purchaser and the Vendor.

• Supports for Pulsation Suppression Devices Omit the bullet and words "if specified."

INSPECTION, TESTING AND PREPARATION FOR SHIPMENT

• General

4.1.1 (Add) Whenever the specification or purchase order calls for certain shop inspections and tests to be witnessed, observed or performed by a purchaser's representative, the vendor shall provide a minimum of five (5) working days written notice prior to a test date or a shop inspection.

• Inspection

• (New) Shop inspections shall include verification of the equipment dimensions and machining tolerances, examination of test data and checking in preparation for shipment.

• (New) The inspector will indicate compliance in accordance with the inspector's checklist,

EP 6-2-,1C by initialing, dating and submitting the completed checklist to the Purchaser before ……………...shipment.

4.2.2.3.3 (Substitution) Replace the last sentence with the following: Crankshafts shall be ultrasonically inspected in accordance with ASTM A503 and wet fluorescent mag particle inspected in accordance with ASTM A275 after machining but before drilling.

4.3 Testing

4.3.1.2 (Add) Acceptance criteria shall include, but not limited to, acceptable vibration and bearing race, or housing, temperature limits. In addition, the vendor shall submit calibration certificates for all test instrumentation.

4.3.1.4 (Add) The vendor shall include a typical procedure for the mechanical running test in the proposal.

• (Substitute) Auxiliary system consoles shall receive both an operational test and a 4-hour mechanical running test prior to shipment. Auxiliary equipment not integral with the unit, such as auxiliary oil pumps, oil coolers, filters, intercoolers, and aftercoolers, etc., shall be subjected to a functional test and cleanliness verification as a subassembly in the vendor's shop, if not used during the compressor or console 4-hour running test. Test procedures and acceptance criteria shall be submitted with the equipment proposal.

• (Substitute) The Purchaser reserves the right to require dismantling for inspection if there is evidence of malfunction during shop tests, excessive repairs, improper fabrication or injurious defects. Dismantling for inspection would be as extensive as necessary to verify manufacturing integrity.

4.3.4.2 (Add) In addition, compressor control system and all associated instrumentation shall be demonstrated to be fully and properly functional.

4.4 Preparation for Shipment

4.4.1 (Add) The vendor shall submit the manufacturer's standard procedure for preservation and packaging for Purchaser review with the proposal.

4.4.5.1 (Add) Stainless steel parts shall not be painted.

4.4.11 (Add) All piping shipped separately shall have a stainless steel (AISI Standard Type 300) tag to identify it against the vendor's drawings.

VENDOR'S DATA

• Proposals

• (Add) The installation list shall include the following:

• The vendor must have manufactured at least two compressors of the same model or frame, operating at comparable flow, speed, compressor ratio, power rating, and discharge pressure for a gas of comparable composition and characteristics.

• Compressors meeting the above requirements must have been satisfactorily proven in continuous service for at least two (2) years.

• A list identifying components in the proposed compressor(s), if any, which have not been in two (2) years of continuous, satisfactory service.

5.2.3.t. Omit the bullet and words "when specified."

(NEW) GUARANTEE

• General

• Refer to procurement documents and paragraph 6.2 of this specification.

• Performance Guarantee

•  The equipment shall be guaranteed for satisfactory mechanical performance at startup, shutdown, part-load operations, and all operating conditions specified on the data sheets. The compressor hydraulic performance shall be guaranteed for the rated operating conditions as iUnless otherwise specified on the data sheets, the guaranteed maximum horsepower shall not exceed 103 percent of the specified value.

7.0 TABLES

TABLE 1 DOCUMENTATION REQUIREMENTS

FOR RECIPROCATING COMPRESSORS PER EP 6-2-1

TABLE 1 (CONT'D)

NOTE:

(1) If the document cannot be provided in the format as indicated, the Manufacturer shall consult with the Owner's Engineer for an acceptable alternative.

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