Packaged Integrally Geared Centrifugal Air Compressors

IPE Engineering Practice IPE-EP-6-2-3

Document number: IPE-EP-6-2-3 · Section: 6 — Rotating Equipment

The following paragraph numbers refer to API 672 second edition, dated April 1988, which is part of this Engineering Practice.

INTRODUCTION

's requirements for Packaged, Integrally Geared Centrifugal Air Compressors for General Refinery Service correspond to those of API Standard 672 second edition, April 1988, with the specific options, deletions, additions, substitutions or modifications sanctioned in this Practice.

The paragraph numbers in this Practice correspond to those used in API 672. Paragraph numbers may not be consecutive, however all API paragraphs not mentioned herein shall be considered to be verbatim requirements of this Practice.

Instructions contained in this Practice 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 Practice 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 Practice. If (new) is next to a paragraph number, not appearing in API 672, it shall be read as an added requirement.

The Purchaser's requirements for all paragraphs in API 672 which require a Purchaser's decision (bulleted paragraphs) are indicated on the Data Sheets or in this Practice. If not addressed in the inquiry, the proposal shall clearly state the basis included in the pricing furnished.

Table 2 records the vendor drawing and data requirements.

NOTE: U.S. Customary units shall be regarded as standard. SI (metric) units in API 672 and this supplement are included for convenience reference only and shall not be interpreted as precise conversions.

GENERAL

Scope

(New) The vendor shall quote in strict accordance with the bid inquiry. Alternative bids are acceptable; however, deviations must be completely documented.

This specification, together with EP 6-7-1, the purchase order, and the Data Sheets (EP 6-2- 3 DS) cover the requirements for centrifugal plant and instrument air compressor packages.

A revision bar indicates all changes made to this Revision.

Conflicting Requirements

(Substitute) In case of conflict between the various documents, their order of precedence is generally as follows:
Purchase Order
Data Sheets
Project Specifications
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 herewith will be the joint responsibility of Purchaser and 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 these mandatory requirements.

Referenced Publications

(Add) The latest revision of the following Practices and Standards shall also apply to the equipment.

STANDARDS AND PUBLICATIONS

Engineering Practices
EP 6-2-3 DS Packaged Integrally Geared Centrifugal Air Compressors Data Sheet EP 6-3-1 General Purpose Steam Turbines EP 6-7-1 Special Requirements for Rotating Equipment EP 6-9-1 Special Purpose Lube/Seal Oil Systems EP 8-1-1 TEMA Shell and Tube Heat Exchangers EP 12-1-1 Control Systems EP 12-2-1 Control Systems Installations EP 13-3-1 Induction Motors 500 HP and Below EP 13-3-2 Induction Motors Above 500HP EP 13-3-3 Synchronous Motors
API Standards
Std 671 Special Purpose Couplings for Refinery Service

(Substitute) This paragraph of APl 672 does not apply to this Practice (See 1.2.3 above).

BASIC DESIGN

General

(Add) When two or more units are provided for the same service, they shall be designed for parallel operation. When new units are to be utilized in parallel with existing capacity, the new units shall be compatible with the existing units.

(Add)

Expansion Joints
Inlet Butterfly Valve Control
Control Panel Assembly
(Add) All equipment and auxiliaries covered by this Practice shall be designed for outdoor, unsheltered installation and operation. The weather/environmental conditions are outlined in the attached Data Sheets under " Site Data". The vendor shall list in the proposal any special protective measures required or recommended.

(Substitute) Engineering Coordination

 Unless otherwise specified, the compressor vendor shall coordinate, expedite, and resolve all sub-vendor problems. The vendor shall also guarantee and be responsible for the design and satisfactory performance of the complete unit, i.e., compressor, driver, 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.

(Add) The vendor shall be responsible for the compatibility of the package starting characteristics with the rest of the system. The unit shall be capable of startup and operation during the coldest weather per the Site Data.

(Add) Omit the bullet and add: "The maximum allowable noise level for each noise source shall comply with the requirements of the Owner's Recommended Environmental Guidelines. If noise attenuation enclosures are required, equipment shall be enclosed with instruments and piping connections on the outside of the enclosures. The enclosure(s) shall have adequate provisions for servicing the equipment and for ventilation.

2.2 Package

2.2.1 Lubrication

2.2.1.4.5 (Add) When specified on the Data Sheets, Oil coolers shall be in accordance with EP 8-1-1. Coolers shall include carbon steel shell and covers, naval brass tube sheets with 5/8 inch O.D., #16 BWG inhibited admiralty tubes. Water shall be on the tube side.

Piping

General

(Add) Seamless carbon steel piping ASTM A53, Grade B shall not be used.

(Add) Fittings shall be of (304) stainless steel, Crawford Swagelok type.

(Substitute) The minimum size of any connection shall be NPS 1/2 inch.

Baseplate

(Add) The baseplate mating surfaces (pads) shall be larger than the foot of the mounted equipment to allow leveling of the baseplate without removal of the equipment. The pads shall be fully machined flat to 0.001 inches per foot. Corresponding surfaces shall also be parallel within 0.002 inches per foot of distance between the pads. These requirements shall be met by supporting and clamping the baseplate at the foundation bolt holes only.

Controls and Instrumentation

 (Add) Unless otherwise specified, instrumentation and installation shall be in accordance with EP 12-1-1 and EP 12-2-1.

Instrument and Control Panel

2.2.4.3.1 n. (New) All gauge board mounted instruments.

Temperature gauges.

Instrument oil gauges.

Air discharge temperature (prior to after cooler).

Suction and discharge air temperature for each stage of compression.

(Add) When more than one wiring point is required on a compressor for instrumentation control, wiring to each switch or instrument shall be provided from a single terminal box mounted on the compressor or on the compressor base, if any.

(New) All pneumatic instrument lines and fittings within the confines of the panel shall be the Manufacturer's standard. All connectors shall be Crawford Swagelok type. Plastic tubing is unacceptable.

Pressure Gauges

(Add) The following locally mounted pressure gauges shall be specified as a minimum:

Compressor discharge pressure.
Bearing oil supply.
Differential oil pressure across filter.
Suction and discharge air pressure for each stage of compression

(New) The following locally mounted instrumentation shall be provided as a minimum:

Inlet and outlet cooling water temperature for each water cooled exchanger.
Oil reservoir level indication.
Suction and discharge air temperature for each stage of compression.
(New) Oil sample provisions are required at the outlets of each bearing.

Alarms and shutdowns

General

(Add) Alarms and shutdown settings shall also be indicated on vendor's drawings.

Alarm and Shutdown Switches

(Add) Alarms will be local with provision for a remote common trouble alarm. There shall also be provision for remote shutdown indication in accordance with Table 1.

Integrally Geared Compressor

External Forces and Moments

2.3.4.2 (Add) The seller shall provide all required inlet and outlet air line expansion joints.

Rotating Elements

2.3.5.1 Shafts

2.3.5.1.3 (Revise the last sentence to read) These areas shall be properly demagnetized or otherwise treated so that the combined total electrical and mechanical runout does not exceed 0.25 mils (6 micrometers).

2.3.7.4 Torsional Analysis

2.3.7.4.5 (Substitute) The vendor shall perform a torsional vibration analysis of the complete coupled train and shall be responsible for directing the modifications necessary to meet the requirements of 2.3.7.4.1 through 2.3.7.4.4 on all trains having synchronous motors, variable speed motors, and on all trains above 2500 HP (1865 KW).

2.3.7.5 Vibration and Balancing

2.3.7.5.7 (Substitute) If the vendor can demonstrate that electrical or mechanical runout is present, it shall be vectorially subtracted from the vibration signal measured during the factory test.

2.3.8 Bearings and Bearing Housings

2.3.8.1 (Add) In general, the Manufacturer's standard load bearing and thrust bearing arrangement is acceptable. Bearing arrangements which require removal of the impeller for bearing replacement are unacceptable.

2.3.8.4  (Add) Hydrodynamic thrust bearing sizing shall be reviewed and approved by the Owner's Engineer.

2.3.8.5.1 (Substitute) Gear type couplings are unacceptable (see 2.5.1.1).

2.3.8.7 (Add) Bearing housings shall be furnished with proper vents/oil breathers to facilitate lube oil drainage.

2.3.9 Materials

2.3.9.1 General

2.3.9.1.2 (Add) Major unidentified parts (gaskets, nuts, bolts, washers, etc.) shall have the same corrosion resistant properties as major parts under similar conditions.

Castings

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

 (Add) These weld procedures for all major weld repairs to pressure-containing castings shall be submitted to the Purchaser for specific approval prior to making repairs. Major weld repairs include the following:

Any repairs to cast iron components.
Repairs to correct a hydrostatic test defect.
Any repair where the excavated area exceeds 10 square inches.
Any repair where the depth of excavated area exceeds 20% of wall thickness or 1 inch, whichever is smaller.

2.3.9.4 Low Temperature

(Add) The vendor shall indicate in the proposal when material thickness is not covered by the Code and shall furnish proposed test methods and criteria.

2.4 Driver

2.4.4 (Add) Electric motors shall comply with EP 13-3-1, EP 13-3-2, and EP 13-3-3 depending on their type and size.

2.4.7 (Add) Steam turbine drivers shall conform to EP 6-3-1.

2.5 Driver-to-Compressor Coupling and Guard

(Add) The coupling shall be of a nonlubricated, piloted spacer type design with stainless steel flexible disks. Lubricated couplings are unacceptable. Rexnord Series 52 or Series 71 are preferred.

(Add) The coupling spacer shall be at least 5 inches long.

2.5.1.7 (Add) It is strongly recommended that whenever tapered shafts/coupling bores are used, that these be non-keyed, hydraulic fit.

2.5.3 (New) For compressors operating above 3600 rpm, couplings shall be dynamically balanced in conformance to API 671, Second Edition paragraph 2.5.2.1.

INSPECTION, TESTING AND PREPARATION FOR SHIPMENT

General

4.1.4 (Add) The vendor shall give the Purchaser a minimum of five (5) working days written notice prior to a test date or a shop inspection.

Inspection

Material Inspection

 (Add) When specified . . .

 (Add) When specified . . .

Mechanical Inspection

(Substitute) The oil system furnished shall meet the cleanliness requirements of EP 6-9-1.

Testing

4.3.1 General

4.3.1.3 (New) Prior to the test, the shop lube system, unit bearing housings and all interconnecting piping shall be thoroughly flushed to assure the cleanliness of the system.

4.4 Preparation for Shipment

4.4.3 (Add) In addition to the requirements of 4.4.3.1 through 4.4.3.12, equipment shall be prepared for shipment in accordance with EP 6-7-1.

4.4.3.1 (Substitute) Exterior surfaces, except for machined surfaces, shall be given one coat of primer suitable for casing temperature and outdoor installation. Moreover, at least one coat of the manufacturer's standard paint shall be applied after testing and field inspection. Stainless steel parts need not be painted.

VENDOR'S DATA

Proposals

5.1d (Add) Horsepower requirements shall include that for a shaft driven oil pump. Also, shaft air leakage shall be included in SCFM calculations. Data on the inlet air filter performance shall be provided.

5.1i (Add) The description, Manufacturer's name and part numbers of the oil filter, air filter, and other consumables shall be included with the parts list. The spare parts list shall include quoted prices and delivery.

r (Add) Data on the inlet air filter performance shall be provided.

Contract Data

Drawings

(Add) Attached to each final schematic drawing of each auxiliary system shall be a bill of materials describing in detail each item of accessory equipment including:
Manufacturer
Type of equipment
Catalog number (model)
Electrical information
Set point and ranges for instruments and control valves
Capacities
Pressures and horsepower for oil pumps
User's identification (tag) number

(NEW) GUARANTEE AND WARRANTY

General

Refer to the Owner's procurement documents and paragraphs 6.2 and 6.3 of this Practice.

Mechanical

Unless exception is recorded by the vendor in his proposal, it shall be understood that the vendor agrees to the guarantees and warranties specified in 6.2.1 and 6.2.2 listed below.

All equipment and component parts shall be warranted by the vendor against defective materials, design, and workmanship for one year after being placed in service (but not more than 18 months after date of shipment).

If any malfunctions or defects occur during the guarantee and warranty period, the vendor shall make all necessary alterations, repairs, and replacements free of charge, free on board factory. Field labor charges, if any, shall be subject to negotiation between the vendor and the purchaser.

Performance

The equipment shall be guaranteed for satisfactory mechanical performance at all operating conditions specified in paragraph 4.3.4.3.2. The aerodynamic performance shall be guaranteed at rated points per paragraphs 2.3.12, 2.3.1.2.1, and 2.3.1.2.2, unless otherwise specified on the Data Sheets.

7.0 TABLES

Table 1: CONDITIONS REQUIRING ALARMS AND SHUTDOWNS

Condition	Alarm	Shutdown
High vibration-compressor High last-stage inlet air temperature Low lube-oil pressure High oil-filter differential pressure High oil-cooler differential pressure Low sealing-system pressure Operation of standby oil pump Low lube-oil level in reservoir (1) High inlet-air-filter differential pressure High vibration-driver (2) Panel purge (3) Surge recognition Permissive start contact High interstage air temperature (all stages) High lube oil supply temperature Low lube oil supply temperature	X X X X X X X X X X X X (4) X X	X X X X X X X

NOTES:

With oil-heater cutout.
If specified.
If required.
Separate pilot-light indication.

TABLE 2 DOCUMENTATION REQUIREMENTS

FOR PACKAGED INTEGRALLY GEARED CENTRIFUGAL AIR COMPRESSORS PER EP 6-2-3

Item	Description	Format (1)	As-Built
1	Certified dimensional outline drawing and list of connections	See EP 2-5-2	Yes
2	Cross-sectional drawing and bill of materials	See EP 2-5-2	Yes
3	Thrust-bearing assembly drawing and bill of materials	See EP 2-5-2	Yes
4	Journal-bearing assembly drawing and bill of materials	See EP 2-5-2	Yes
5	Shaft-coupling assembly drawings and bill of materials	See EP 2-5-2	Yes
6	Electrical and instrumentation schematics and bill of materials	See EP 2-5-2	Yes
7	Electrical and instrumentation assembly drawings and list of connections	See EP 2-5-2	Yes
8	Tabulation of utility requirements	See EP 2-5-2	Yes
9	Curves showing polytropic head and efficiency versus ICFM	See EP 2-5-2	Yes
10	Curves showing discharge pressure and brake efficiency versus ICFM	See EP 2-5-2	Yes
11	Vibration analysis data	See EP 2-5-2	Yes
12	Lateral critical analysis report	See EP 2-5-2	Yes
13	Torsional critical analysis report	See EP 2-5-2	Yes
14	Transient torsional analysis report	See EP 2-5-2	Yes
15	Allowable flange loading	See EP 2-5-2	Yes
16	Alignment diagram	See EP 2-5-2	Yes
17	Weld procedures	See EP 2-5-2	Yes
18	Certified hydrostatic test logs	See EP 2-5-2	Yes
19	Mechanical running test logs	See EP 2-5-2	Yes
20	Performance test logs	See EP 2-5-2	Yes
21	Nondestructive test procedures	See EP 2-5-2	Yes
22	Certified mill test reports	See EP 2-5-2	Yes
23	Rotor balancing logs	See EP 2-5-2	Yes
24	Rotor combined mechanical and electrical runout	See EP 2-5-2	Yes
25	As-built data sheets	See EP 2-5-2	Yes
26	As-built dimensions and data	See EP 2-5-2	Yes
27	Installation manual	See EP 2-5-2	Yes
28	Operating and maintenance manuals	See EP 2-5-2	Yes

TABLE 2 (CONT.) DOCUMENTATION REQUIREMENTS

FOR PACKAGED INTEGRALLY GEARED CENTRIFUGAL AIR COMPRESSORS PER EP 6-2-3

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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