IPS-E-PR-400

ENGINEERING STANDARD

FOR

PROCESS DESIGN OF COOLING WATER CIRCUITS

ORIGINAL EDITION

JULY 1994

This standard specification is reviewed and

updated by the relevant technical committee on
Feb. 1999(1), Oct. 2004(2) and Dec. 2013(3). The
approved modifications are included in the
present issue of IPS.

This Standard is the property of Iranian Ministry of Petroleum. All rights are reserved to the owner.
Neither whole nor any part of this document may be disclosed to any third party, reproduced, stored in
any retrieval system or transmitted in any form or by any means without the prior written consent of the
Iranian Ministry of Petroleum.
 July 1994
IPS-E-PR-400

FOREWORD
The Iranian Petroleum Standards (IPS) reflect the views of the Iranian Ministry of Petroleum and are
intended for use in the oil and gas production facilities, oil refineries, chemical and petrochemical
plants, gas handling and processing installations and other such facilities.
IPS is based on internationally acceptable standards and includes selections from the items
stipulated in the referenced standards. They are also supplemented by additional requirements
and/or modifications based on the experience acquired by the Iranian Petroleum Industry and the
local market availability. The options which are not specified in the text of the standards are
itemized in data sheet/s, so that, the user can select his appropriate preferences therein
The IPS standards are therefore expected to be sufficiently flexible so that the users can adapt
these standards to their requirements. However, they may not cover every requirement of each
project. For such cases, an addendum to IPS Standard shall be prepared by the user which
elaborates the particular requirements of the user. This addendum together with the relevant IPS
shall form the job specification for the specific project or work.
The IPS is reviewed and up-dated approximately every five years. Each standards are subject to
amendment or withdrawal, if required, thus the latest edition of IPS shall be applicable
The users of IPS are therefore requested to send their views and comments, including any
addendum prepared for particular cases to the following address. These comments and
recommendations will be reviewed by the relevant technical committee and in case of approval will
be incorporated in the next revision of the standard.

Standards and Research department

No.17, Street14, North kheradmand
Karimkhan Avenue, Tehran, Iran.
Postal Code- 1585886851
Tel: 021-88810459-60 & 021-66153055
Fax: 021-88810462
Email: Standards@nioc.ir
 July 1994
IPS-E-PR-400

GENERAL DEFINITIONS:
Throughout this Standard the following definitions shall apply.

COMPANY:
Refers to one of the related and/or affiliated companies of the Iranian Ministry of Petroleum such as
National Iranian Oil Company, National Iranian Gas Company, National Petrochemical Company
and National Iranian Oil Refinery And Distribution Company.

PURCHASER:
Means the “Company” where this standard is a part of direct purchaser order by the “Company”,
and the “Contractor” where this Standard is a part of contract documents.

VENDOR AND SUPPLIER:

Refers to firm or person who will supply and/or fabricate the equipment or material.

CONTRACTOR:
Refers to the persons, firm or company whose tender has been accepted by the company.

EXECUTOR:
Executor is the party which carries out all or part of construction and/or commissioning for the
project.

INSPECTOR:
The Inspector referred to in this Standard is a person/persons or a body appointed in writing by the
company for the inspection of fabrication and installation work.

SHALL:
Is used where a provision is mandatory.

SHOULD:
Is used where a provision is advisory only.

WILL:
Is normally used in connection with the action by the “Company” rather than by a contractor,
supplier or vendor.

MAY:
Is used where a provision is completely discretionary.
 July 1994
IPS-E-PR-400

CONTENTS: PAGE No.

0. INTRODUCTION ............................................................................................................................. 2
1. SCOPE ............................................................................................................................................ 3
1.1 General ..................................................................................................................................... 3
2. REFERENCES ................................................................................................................................ 3
3. DEFINITIONS AND TERMINOLOGY ............................................................................................. 4
4. SYMBOLS & ABBREVIATIONS .................................................................................................... 7
5. UNITS .............................................................................................................................................. 7
6. DESIGN ........................................................................................................................................... 7
6.1 Internal Combustion Engines, Cooling Systems ................................................................. 7
6.1.1 General.............................................................................................................................. 7
6.1.2 Methods ............................................................................................................................ 7
6.1.3 Heat transfer ..................................................................................................................... 8
6.1.4 Heat lost to cylinder’s inside surface ............................................................................ 8
6.1.5 Requirements of cooling system ................................................................................... 8
6.1.5.1 Design features ........................................................................................................ 8
6.1.5.2 Equipment/devices and process design ................................................................ 9
6.2 Reciprocating Compressors’ Cooling System .................................................................... 9
6.2.1 General.............................................................................................................................. 9
6.2.2 Methods ............................................................................................................................ 9
6.2.3 Calculation of heat rejected to circulating cooling water.......................................... 10
6.2.4 Requirements ................................................................................................................. 10
6.2.4.1 General .................................................................................................................... 10
6.2.4.2 Cylinder jackets cooling ........................................................................................ 11
6.2.4.3 Integral cooling system ......................................................................................... 11
6.2.4.4 Packing box cooling system ................................................................................. 11
6.2.4.5 Lubricating oil cooling system ............................................................................. 11
6.2.5 Design features .............................................................................................................. 12
6.2.6 Piping and appurtenances ............................................................................................ 12
6.2.7 Coolers............................................................................................................................ 13
6.2.8 Cooling water reservoir................................................................................................. 14
6.2.9 Circulating pumps ......................................................................................................... 14
6.3 Design Requirements and Features for Intercooling and Aftercooling Facilities .............. 15

APPENDICES:

APPENDIX A TYPICAL CLOSED COOLING WATER SYSTEM FOR MULTIPLE ENGINE

INSTALLATIONS .................................................................................................... 16
APPENDIX B CYLINDER COOLING SYSTEM ............................................................................. 18
APPENDIX C TYPICAL SELF-CONTAINED COOLING SYSTEM FOR PISTON ROD
PRESSURE PACKING ........................................................................................... 19

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 July 1994 IPS-E-PR-400

COOLING WATER CIRCUITS

0. INTRODUCTION
The primary purpose of IPS standard specifications on "Process Design of General Heating &
Cooling and Flushing Systems" is to establish minimum requirements and design criteria needed in
process design of the following standards:

STANDARD CODE STANDARD TITLE

IPS-E-PR-400 “Engineering Standard for Process Design of Cooling Water
Circuits”
IPS-E-PR-410 “Engineering Standard for Process Design of Hot Oil & Tempered
Water Circuits”
IPS-E-PR-420 “Engineering Standard for Process Design of Heat Tracing and
Winterizing”

"PROCESS DESIGN OF COOLING WATER CIRCUITS"

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 July 1994 IPS-E-PR-400

1. SCOPE

1.1 General
This Standard Specification covers:
- Cooling Water Circuits for Internal Combustion Engines.
- Cooling Water Circuits for Reciprocating Compressors.
- Cooling Water Circuits for Inter cooling and After cooling Facilities.

Note 1:
This standard specification is reviewed and updated by the relevant technical committee on
Feb. 1999. The approved modifications by T.C. were sent to IPS users as amendment No. 1
by circular No. 46 on Feb. 1999. These modifications are included in the present issue of IPS.

Note 2:
This standard specification is reviewed and updated by the relevant technical committee on
Oct. 2004. The approved modifications by T.C. were sent to IPS users as amendment No. 2
by circular No. 243 on Oct. 2004. These modifications are included in the present issue of
IPS.

Note 3:
This standard specification is reviewed and updated by the relevant technical committee on
Dec. 2013. The approved modifications by T.C. were sent to IPS users as amendment No. 3
by circular No. 411 on Dec. 2013. These modifications are included in the present issue of
IPS.

2. REFERENCES
Throughout this Standard the following dated and undated standards/codes are referred to. These
referenced documents shall, to the extent specified herein, form a part of this standard. For dated
references, the edition cited applies. The applicability of changes in dated references that occur
after the cited date shall be mutually agreed upon by the Company and the Vendor. For undated
references, the latest edition of the referenced documents (including any supplements and
amendments) applies.

TEMA (TUBULAR EXCHANGER MANUFACTURERS ASSOCIATION, INC)

TEMA Class R Heat Exchangers

IPS (IRANIAN PETROLEUM STANDARS)

IPS-E-PR-440 “Engineering Standard for Process Design of Piping Systems
(Process Piping and Pipeline Sizing)”
IPS-E-PR-750 “Engineering Standard for Process Design of Compressors”
IPS-E-PR-785 “Engineering Standard for Process Design of Air Cooled Heat
Exchangers (Air Coolers)”
IPS-G-ME-100 “General Standard for Atmospheric Above Ground Welded Steel
Storage Tanks”
IPS-G-ME-110 “General Standard for Large Welded Low Pressure Storage
Tanks”

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 July 1994 IPS-E-PR-400

IPS-E-PR-310 “Engineering Standard for Process Design of Water Systems”

IPS-C-ME-130 “Construction Standard for LPG Pressure Storage Spheres”
IPS-E-PR-771 “Engineering Standard for Process Requirements of Heat
Exchanging Equipment”
IPS-E-ME-130 “Engineering Standard for LPG Pressure Storage Spheres”
IPS-G-ME-220 “General Standard for Shell & Tube Heat Exchangers”
IPS-E-PM-100 “Engineering Standard for General Design Requirements of
Process Machineries”

API (AMERICAN PETROLEUM INSTITUTE)

ANSI/API 610N:2010 “Centrifugal Pumps for Petroleum, Petrochemical and Natural
th
Gas Industries”, Edt.11
API 618:2007 “Reciprocating Compressors for Petroleum, Chemical and Gas
th
Industry Services”, Edt. 5
ANSI/API 619:2010 “Positive Displacement Compressors for Petroleum, Chemical
th
and Gas Industry Services”, Edt. 5
ANSI/API 660:2007 “Shell-and-Tube Heat Exchangers for General Refinery
th
Services”, Edt. 8
ANSI/API 661:2006 “Air-Cooled Heat Exchangers for General Refinery Services”,
th
Edt. 6

ASME (AMERICAN SOCIETY OF MECHANICAL ENGINEERS)

ASME No. 120, Prepared by Pannel IV of Joint ASME-ASTM-NEMA
Committee on "Gas Turbine Lubrication System", Clause
6.0, "Coolers", Louisville, Ky, May 1957.
ASME Sec. VIII,Div.1 Part 2, Appendix A.

ISO (INTERNATIONAL STANDARD ORGANIZATION)

EN ISO 13631 “Petroleum and natural gas industries -Packaged reciprocating
gas compressors”

3. DEFINITIONS AND TERMINOLOGY

3.1 After-Cooler
After-Cooler is a type of surface condenser in which compressed air/gas is cooled after
compression.

3.2 Air-Cooler
Air-Cooler is an exchanger in which the heating surface is directly cooled by air.

3.3 Ambient Temperature

Ambient Temperature is the temperature level of atmosphere in the environment of the equipment
installation.

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3.4 Brake Kilowatt

Brake Kilowatt is the actual power input at the crankshaft of the compressor driver.

3.5 Combustion
Combustion is the rapid oxidation of fuel accompanied by production of heat.

3.6 Condensation
Condensation occurs when a saturated vapor comes in contact with a surface whose temperature is
below the saturation temperature.

3.7 Cooling System

Cooling System is a self-contained, closed/open cooling water system, capable for taking the heat
transmitted to the heating surface, to the extend specified by the manufacturer.

3.8 Energy Conservation

Energy conservation is saving in power consumption, as by rough estimate, each 5.5°C decrease in
gas temperature between the stages shall result in one percent in power consumption (see ASME
Standard No. 120 & Power Plant Engine Guides).

3.9 Heating Surface

Heating surface is the surface which transmits heat directly from the heating medium to the cooling
medium.

3.10 Inlet Temperature

Inlet temperature is the temperature of liquid coolant entering the heating surface at specified point
in the inlet piping.

3.11 Inter-Cooler
Inter-cooler is a type of surface condenser placed between the two consecutive cylinders of a
multistage compressor so that, the heat of compression generated in the first stage cylinder is
removed (in part or whole) from the compressed air/gas.

3.12 Liquid Coolant System

Liquid coolant system is the coolant system by which the heating surfaces are cooled by liquid.

3.13 Maximum Allowable Working Pressure (MAWP)

Maximum allowable working pressure is the maximum continuous pressure for which the
manufacturer has designed the equipment (or any part to which the term is referred) when handling
the specified fluid at the specified temperature.

3.14 Maximum Suction Pressure

Maximum suction pressure is the highest allowable suction pressure to which the pump/compressor
is subjected during operation.

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3.15 Multi-Stage Reciprocating Compressor

Multi-stage reciprocating compressor is the compressor in which the compression, when a perfect
gas or air is isentropically compressed, the gas inlet temperature as well as the amount of work
spent is the same of each stage.

3.16 Net Positive Suction Head Required (NPSHR)

Net positive suction head required (NPSHR) is the NPSH in meters, determined by the vendor
testing, usually by water. NPSHR is measured at the suction flange and corrected to the datum
elevation. NPSHR is the minimum NPSH at rated capacity required to prevent a head drop of more
than 3 percent due to cavitation within the pump.

3.17 Outlet Temperature

Outlet temperature is the temperature of liquid coolant discharged from the heating surface at
specified point in the outlet piping.

3.18 Rated Capacity

Rated capacity is rated process capacity specified by the Company to meet process conditions with
No Negative Tolerance (NNT) permitted.

Note:
The acceptable standard for reciprocating compressor industry, tolerance of ±3 percent is
applicable to capacity. Because of this tolerance on capacity, the manufacturer will increase
the required capacity by 3 percent prior to sizing the compressor.

3.19 Rated Discharge Temperature

The rated discharge temperature is the highest predicted (not theoretical adiabatic) operating
temperature resulting from the rated service conditions.

3.20 Rated Speed in Rotations (Revolutions) Per Minute

Rated speed in rotations (revolutions) per minute is the highest speed required to meet any of the
specified operating condition.

3.21 Seal Chamber Pressure

Seal chamber pressure is the highest pressure expected at the seals during any specified operating
condition and during start up and shut down. In determining of this pressure, consideration should
be given to the maximum suction pressure, the flushing pressure and the effect of internal
clearance changes.

3.22 Working Pressure

Working pressure is the maximum continuous pressure for which the manufacturer has designed
the equipment (or any part to which the term is referred).

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4. SYMBOLS & ABBREVIATIONS

FI = Flow Indicator
F = Filter
LAL = Level Alarm Low
LAH = Level Alarm High
LG = Level Gage
LSL = Level Switch Low
OWS = Oily Water Sewer
PI = Pressure Indicator
PAL = Pressure Alarm Low
PDAH = Pressure Differential Alarm High
PDSH = Pressure Differential Switch High
PRV = Pressure Relieve Valve
PSL = Pressure Switch Low
RO = Restriction Orifice
TI = Temperature Indicator
TCV = Temperature Control Valve

5. UNITS
This standard is based on international system of units (SI), as per IPS-E-GN-100 except where
otherwise specified.

6. DESIGN

6.1 Internal Combustion Engines, Cooling Systems

6.1.1 General
When the fuel is burnt in the cylinder, a part of the heat developed during combustion, flows to
cylinder walls. If the temperature of cylinder walls is allowed to rise above a certain limit (about
150°C) then the oil lubricating the piston starts evaporating. This action damages both piston and
cylinder. The high temperature developed may sometimes cause excess thermal stresses and
hence cracking of the cylinder head and piston. The hot spots may also cause preignition in the
combustion space. In order to avoid any damages, the heat flowing to the cylinder walls must be
carried away.

6.1.2 Methods
All heat carried away from an engine shall finally be conveyed to atmosphere. However, the
methods of cooling may be divided into two main groups of direct or air-cooling and indirect or
liquid-cooling.

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6.1.3 Heat transfer

In cooling of engine cylinders, all three mechanism of heat transfer, i.e., conduction, convection and
radiation will be utilized. But, conduction will play the most important part in carrying the heat
through the thin layers of hot gases and water in contact with cylinder walls and will be sole object
of process design in this Standard.

6.1.4 Heat lost to cylinder’s inside surface

The quantity of heat loss per second to the heating surface i.e, inside surface of cylinder wall, head
and exhaust valve cages by combustion gases shall be considered.

6.1.5 Requirements of cooling system

Unless otherwise specified, the required cooling water system shall include the following features:

6.1.5.1 Design features

a) The closed cooling water system shall either use distilled or treated soft water which is passed
through a heat-exchanger, where it is cooled and then passed through the cylinder jacket.
b) The heat exchanger type used may usually be of shell and tube or air-cooled heat exchanger
which shall be based on Company’s agreement.
c) Within the cylinder jackets, only liquid phase cooling media shall be permitted.
d) The system shall be capable of providing required quantity of water for cooling of cylinder
jackets, cylinder heads, exhaust valve cages and circulating oil.
e) The following operating condition shall be considered in design of cooling system:
1) An uninterrupted flow of cooling water will always be maintained through the cylinder
jackets.
2) The water used for cooling of cylinder jacket shall be free from scale and impurities and
shall not be of corrosive nature. (For more detail of quality of water, refer to IPS-E-PR-310).
3) The inlet water temperature to cylinder jackets shall be maintained at 63°C to 68°C.
4) The maximum water temperature rise within the cylinder jackets including the heat
absorbed from cylinder heads and exhaust valves shall not exceed 10°C.
5) The system shall be designed to meet the working pressure of not less than 520 kPa and
testing pressure of 800 kPa.
6) Thermometers, complete with thermowells shall be fixed at cooling system outlets.
7) A protection device shall be established at cooling system outlet to monitor and act, if the
temperature rise exceed a critical value specified by the manufacturer.
8) A cooling water high temperature alarm shall be provided on cylinder outlet. The alarm
shall actuate and the engine shall shut down when the discharge temperature of any cylinder
exceeds the rated discharge temperature by 22°C.
9) The quantity of circulating water by each pump shall meet the temperature rise across
each and all of the cylinder, cylinder head and the exhaust valve cage and circulating oil.
10) The system shall be provided with an appropriate draining connection. The connection
shall provide facilities for perfect washing, cleaning and draining of the system.
11) Low inlet water temperature to cylinder jackets will increase the viscosity of the lubricating
oil and consequently the piston frictions. Vendor shall make necessary provisions to
automatic control the inlet water temperature at a specified range, as specified in e.3 above.
f) Unless specified otherwise, Vendor shall furnish a detailed drawing for his proposed closed
water cooling system. Company’s recommended drawing shall typically be as per Fig. A.1, in

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Appendix "A".
g) Unless otherwise specified, the Vendor shall supply closed water cooling piping with a single
inlet and a single outlet connection on each cylinder.

6.1.5.2 Equipment/devices and process design

6.1.5.2.1 Unless otherwise specified, the process design of the following equipment/devices shall
constitute a combined, self-contained closed water cooling system for internal combustion engines.
a) Soft water circulating pumps.
b) Soft water circulating piping.
c) Reservoir (or surge tank) for soft water.
d) Soft water circulating, heat exchanger (or cooler).
e) Thermometers for measuring inlet and outlet temperatures.
f) Temperature regulator to control the outlet temperature.
g) A soft water high temperature protective device to control the excessive cylinder jacket
temperature.
6.1.5.2.2 Fig. A.1, in Appendix "A", illustrates the required equipment/devices of an internal
combustion engine’s closed water cooling system.

6.2 Reciprocating Compressors’ Cooling System

6.2.1 General

6.2.1.1 When air/gas is compressed, its temperature and pressure will rise and a considerable heat
will be generated due to rise in temperature. Part of the heat so, generated, will be transferred to
cylinder wall rising the wall temperature which will reduce the lubricating efficiency in cylinder and
might result in, an overheated and warped rod. The heat of compression will also results in a loss
by boosting of pressure.
6.2.1.2 It has been found desirable to remove part of this heat traveled to cylinder wall in order to
get rid of any damage to cylinder barrel and heads. Any heat removed also results in a slight
reduction in the compression brake kilowatt.
6.2.1.3 Unless otherwise specified, the following criteria and specifications of this standard, form the
Company’s minimum requirement for the process design of a complete closed cooling water system
for reciprocating compressor cylinder jackets, it’s engine cylinder jackets, it’s lubricating oil cooling
circuit and the compressor packing box cooling in part or in integral.
6.2.1.4 Throughout this Standard, references are mainly made to the API Standard 618 along with
other internationally acceptable codes, standards and engineering practices and many important
applied design book and resources.

6.2.2 Methods

6.2.2.1 The heat traveled to the cylinder wall can be carried off either by direct air-cooling or by
indirect liquid cooling process. Most cylinders have water jackets to remove the heat and maintain
required cylinder and /or liner temperature. Usually small kilowatt power units may use air-cooling
system.

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6.2.2.2 According to API Standard 618, three following methods of cooling may be used, depending
on the extended period of time where, cylinders will or will not be required to operate fully unloaded.
a) Atmospheric thermosyphon coolant systems (see Figure B.1, Plan B) may be supplied when
cylinders are not required to operate fully unloaded for extended periods of time and either (a)
the expected maximum discharge temperature is 100°C (210°F) or (b) the adiabatic gas
temperature rise is less than 85K (150°F).
By mutual agreement between the purchaser and the vendor, a pressurized thermosyphon
system may be used. The pressurized system may only be used where the expected maximum
gas discharge temperature is not to exceed 105°C (220°F). In such cases, the system shall be
supplied with a thermal relief valve set at a gauge pressure of 1.7 bar (25 psig) maximum.
b) Static field coolant system may be used when the cylinders will not be required to operate
fully unloaded for extended period of time. The expected maximum discharge temperature is
less than 88°C and the rise in adiabatic gas temperature (difference between suction and
discharge temperatures based on the isentropic compression) is less than 66°C (see Fig. B.1 (a)
in Appendix "B").
c) Forced-liquid coolant systems (see Appendix B Figure B.1, Plan C) shall be provided when
cylinders are operated while unloaded for extended periods of time and either (a) the expected
maximum discharge temperature is above 100°C (210°F) or (b) the adiabatic gas temperature
rise is 85K (150°F) or greater.

Note: For sites with ambient temperatures of 45°C (110°F) or higher, thermosyphon or static-
filled systems can be unsuitable. If any of the compressor cylinders are to be operated
partially or fully unloaded for extended periods of time, the purchaser and the vendor shall
jointly determine the method to be used (e.g., periodic, momentary loading to purge
accumulation of lube oil in the compressor cylinders) to prevent heat and liquid damage.

6.2.2.3 Unless otherwise specified, forced closed cooling water system shall be used for taking
away the heat traveled to cylinder wall. The water shall be pumped through the secondary cooler
and then back to cylinder jacket for reuse.
6.2.2.4 The Vendor is required to evaluate the Company’s proposed standard coolant system as
specified under Clause 6.2.2.3 above against his own standard coolant system or any other
standard coolant system and shall recommend the use of the most efficient, effective and techno-
commercially feasible other coolant system together with strong convincing proves. However the
employment of any other coolant system will solely be upon the Company’s written approval.

6.2.3 Calculation of heat rejected to circulating cooling water

6.2.3.1 The Vendor/Manufacturer will furnish complete design data on quantity of compression heat
to be removed from cylinder jacket and head, in kj/min.
6.2.3.2 The Vendor/Manufacturer if deemed necessary may furnish an integral closed cooling water
system for compressor cylinder jackets, engine cylinder jackets, lubricating oil circuit and
compressor packing boxes, he should provide separate design data on the quantity of heat rejected
to cooling system from each section separately and as a whole along with quantity of water
circulating and pressure drops.

6.2.4 Requirements

6.2.4.1 General
A closed cooling water system for packaged reciprocating compressor shall be furnished either in
separate for cylinder jacket cooling or integral with engine cylinder, lubricating oil and cooling of

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compressor packing boxes, within the temperature limit recommended by the manufacturer for the
specified compression services.

6.2.4.2 Cylinder jackets cooling

6.2.4.2.1 Unless otherwise specified, the following requirements shall be considered when the
closed cooling water system is used only for cylinder jacket cooling:
a) The cylinder jackets when designed, all protective measures must be taken to prevent the
process gas flow into the cooling water circuit.
b) An adequate cooling water supply for cylinder jacket and cylinder head must be maintained.
c) The cylinder cooling system shall be designed to prevent gas condensation in the cylinder,
that may dilute or remove lubricant or may cause knocking.
d) The use of untreated or scale depositing water that will cause fouling and plugging of the
water passage, reducing cooling efficiency should strongly be avoided.

6.2.4.3 Integral cooling system

6.2.4.3.1 Not withstanding the requirements set-forth under clause or 6.2.4.2 unless otherwise
specified, the following requirement, shall be considered when the closed cooling water system is
used for an integral compressor and engine cylinder jackets, lubricating oil and packing box cooling:
a) The cooling circuit shall include engine lubricating oil, engine cylinder jacket, compressor
cylinder jacket and packing boxes.
b) Elevated deaerating type reservoir with gage glass, vent line, cooling water level switches,
overflow, filling connections and drains.
c) Cooling water temperature control shall be provided.

6.2.4.4 Packing box cooling system

6.2.4.4.1 If a separate closed cooling circuit is specified for the piston rod pressure packing (see
Fig. C.1, Appendix C), the criteria given in 6.2.4.4.2 and 6.2.4.4.3 shall be followed.
6.2.4.4.2 When packing is cooled by forced circulation, the Vendor shall supply a suitable filter of
appropriate mesh rating.
6.2.4.4.3 Where cooling of packing is required, the Vendor shall be responsible for determining and
informing the Company on the minimum requirements such as flow, pressure, pressure drop and
temperature as well as filtration and corrosion protection criteria. The coolant pressure drop through
the packing case shall not exceed 1.7 bar (25 psig).

6.2.4.5 Lubricating oil cooling system

6.2.4.5.1 Since cooling of the lubricating oil shall be considered as an integral part of the closed
cooling water system, the following recommendations apply:
a) Since liquid coolant is used, the design should minimize the chance of the lube oil being
contaminated.
b) The coolant pressure should be less than the lube oil pressure at all time.
c) Adequate cooling water circulating rate for removal of total heat rejection to lube oil, should be
maintained.

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6.2.5 Design features

6.2.5.1 Unless otherwise specified, the provisions set-forth under 6.1.5.1 of this Standard when
applicable, shall be considered as the design feature for a closed cooling water system for
reciprocating compressors.
6.2.5.2 The cooling water supply to each cylinder jacket shall be at temperature of at least
5K (10°F) above gas inlet temperature as per API Standard 618.
6.2.5.3 The quantity of cooling water circulation by each pump shall be regulated to maintain a rise
in cooling water temperature across only of the individual cylinder and cylinder head between
5K (10°F) to 10K (20°F) (as per API Standard 618).
6.2.5.4 An oil detection device shall be provided in the water supplied to pumps suction head.
6.2.5.5 In case of compressor cylinder cooling, the following should be observed:
a) Coolant inlet temperature less than 5K (10°F) greater than gas inlet temperature may cause
gas constituent condensation.
b) Cooling water rate and velocity shall be provided by the Vendor to prevent fouling of cylinder
jacket system.
c) Cooling water exit temperature more than 17K (30°F) above gas inlet temperature may cause
compressor capacity reduction. (as per API Standard 618).
6.2.5.6 Installations for reciprocating compressor integral with engine cylinder, lubricating and
packing box cooling system shall be as indicated in Fig. E.1 of Appendix "E". The system shall be
capable of providing the following:
a) Cooling water for reciprocating compressor cylinder jackets.
b) Cooling water for engine cylinder jackets.
c) Cooling water for lubricating oil coolers.
d) Cooling water for cooling of compressor packing boxes (or in case of refrigeration services,
water for warming of packing).
6.2.5.7 Typical installation for cylinder jackets and cylinder head cooling system of the reciprocating
compressor is indicated in Fig. B.1 of Appendix "B".
6.2.5.8 Typical installation for packing box cooling system of the reciprocating compressor is
indicated in Fig. C.1 of Appendix "C".

6.2.5.9 Working pressure

The system shall be designed for not less than 520 kPa working pressure and a hydraulic test
pressure of 800 kPa.

6.2.6 Piping and appurtenances

6.2.6.1 Unless otherwise specified by the Company, the Vendor shall supply a closed cooling water
piping system for all equipment mounted on the compressor package. The piping shall be arranged
to provide single flanged inlet and outlet connections at the edge of the skid. Necessary valves and
bypasses shall be provided for temperature control.(See Figs. A.1, C.1, & E.1 of Appendices "A",
"C", & "E" as the case may be).
6.2.6.2 Unless otherwise specified, piping design, inspection and testing shall be in accordance with
relevant IPS-E-PR-440.
6.2.6.3 The piping of the cooling system shall be pre-fabricated, factory skid mounted and complete
with various pressure and temperature indicators, alarm and other specific instrumentation required.

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 July 1994 IPS-E-PR-400

6.2.6.4 The inlet water connections shall be located at the lowest point of cylinder, so that water can
easily be drained from cylinder when compressor is shut down.
6.2.6.5 The discharge connection should be at the highest point to ensure of complete filling of
water jackets with no air pockets.
6.2.6.6 The water piping should be equipped with a valve controlling the flow of water.
6.2.6.7 If the Company does not specify the extent of closed cooling water piping, the Vendor shall
supply piping with single inlet and a single outlet connection on each cylinder requiring cooling (see
Appendix "B", Fig. B.1, Plan c).
6.2.6.8 Coolant piping shall be arranged so that air can not be trapped. Where air trap can not be
avoided, vent connection shall be provided. Low points shall have drains.
6.2.6.9 Both, cooling water inlet and outlet lines to each compressor cylinder shall be provided with
a gate valve. A globe valve with union shall be provided on the main outlet line from each cylinder.
A sight glass flow and temperature indicator shall be installed in the outlet line from each cylinder.

Note:
Where more than one cooling water inlet and outlet point exist on a cylinder, one sight glass
flow indicator and regulating globe valve shall be provided for each outlet point on each
cylinder.

6.2.6.10 For the packaged reciprocating compressor, Vendor shall supply all necessary piping,
valves and fittings for all instrument and instrument panel.
6.2.6.11 The cylinder cooling system piping shall be equipped with vents and low point drains.
Manual block valves to permit working on the compressor unit or auxiliary equipment without
draining the engine cooler shall be furnished.
6.2.6.12 Internals of piping and appurtenances shall be accessible through openings or by
dismantling for complete visual inspection and cleaning.

6.2.7 Coolers

6.2.7.1 Unless otherwise specified by the Company, shell and tube heat exchanger shall be used
for forced closed cooling water system on reciprocating compressors and internal combustion
engine cylinder cooling.
6.2.7.2 The Vendor shall advise, when a cooler other than shell and tube exchanger is preferred.
However the use of any cooler other than shell and tube, shall only be made upon the Company’s
written approval.
6.2.7.3 Heat exchanger’s tube-bundle shall be designed removable with clean and non corrosive
fluid flowing through the tube side.
6.2.7.4 Process design of shell and tube exchanger shall be in accordance with IPS-E-PR-771.
6.2.7.5 The following recommendations shall be applied for the coolers used in closed cooling water
system in general and for the lubricating oil cooler in particular:
a) The heat exchange surface should be located and arranged so that it can be removed for
maintenance or replacement.
b) Provide means for draining both sides of the cooler during shutdown.

Cautions:
These drains need to be protected from draining the reservoir during operation.

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 July 1994 IPS-E-PR-400

c) Vent connections should be provided on the cooler to permit air removal.

d) When dual coolers are used, the three-way change over valve should be designed so that oil
flow will not be interrupted when transferring from one cooler to the other.
e) Since liquid coolant is considered to be mainly used, the design should minimize the chance
of lube oil being contaminated. Separate seals or gaskets should be provided for the coolant and
the lube oil sealing. The space between the seals should be open to the ambient.
6.2.7.6 When air-cooled heat exchanger is recommended to be used by the Company, its process
design shall conform to IPS-E-PR-785.

6.2.8 Cooling water reservoir

6.2.8.1 The cooling water reservoir should be located above the highest point of the closed cooling
water system.
6.2.8.2 Working capacity of the reservoir shall be at least equal to the normal capacity of the pump
per 5- minutes.
6.2.8.3 The reservoir shall be furnished with appropriate level indicator, with sufficient length
covering working range of the reservoir and normal expansion and contraction of the system.
6.2.8.4 Level control system shall be provided for automatic control and maintaining of desired level
and pumping suction head.
6.2.8.5 The reservoir shall be furnished with level switches and alarm, vent/overflow and filling
connection and drain.
6.2.8.6 The reservoir vent/overflow line size shall have a diameter not less than ½ the diameter of
the pump suction line.
6.2.8.7 The design of the suction line from the reservoir to the pump shall not provide any air
pocket.
6.2.8.8 Reservoir shall be furnished with necessary chemical injection facilities to control more
corrosive nature of circulating water.
6.2.8.9 Provisions shall be considered for blanketing and spilling out the air from the reservoir (e.g.
using steam or N2 or …).
6.2.8.10 The Company shall specify whether the installation is to be indoor or outdoor and the
climatic conditions, including maximum and minimum temperature. The Vendor shall take all
necessary protective measures in design by proper winterizing of the reservoir and other auxiliaries
in cooling water system.

6.2.9 Circulating pumps

6.2.9.1 Unless otherwise specified, two horizontally mounted centrifugal pumps (main and spare)
shall be furnished by the Vendor (see Figs. A.1, B.1, C.1 in Appendices "A", "B", "C").
6.2.9.2 All process design requirements and criteria specified in API 610 and not covered herein
under shall be used as integral part of this Standard.
6.2.9.3 The equipment and auxiliaries shall be designed for a minimum service life of 20 years and
at least 3 years of uninterrupted operation. This shall be considered as a design criterion.
6.2.9.4 The equipment rated operating point shall be specified on the data sheets along with any
other anticipated operating conditions.
6.2.9.5 The Vendor shall specify on the data sheets the NPSHR when pump is operated on water at
the rated capacity and rated speed, when water temperature is less than 66°C.

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 July 1994 IPS-E-PR-400

6.2.9.6 Pumps shall be designed for mechanical sealing in accordance with requirements of IPS-E-
PM-100, unless otherwise noted on data sheets. Pumps shall have mechanical seals with flushing
line to maintain a seal chamber pressure greater than the maximum suction pressure and, to
ensure that the temperature and pressure in the seal chamber prevent vaporization while providing
continuous flow through the seal chamber.
6.2.9.7 Pumps shall be provided with constant-speed motor drivers or steam turbine drive, (if
required by the Company). Motor driver of the pumps(main and spare) shall be on the secondary
selective electric system. (Emergency Power).
6.2.9.8 Each pump shall be designed for capacity required, to maintain complete cooling
requirement of the system.
6.2.9.9 Each pump shall be operative as the spare of the other and shall automatically be started
upon loss of pressure in the discharge of the main pump.

6.3 Design Requirements and Features for Intercooling and Aftercooling Facilities

6.3.1 Unless otherwise specified by the Company, Vendor shall supply water cooled intercoolers
and aftercoolers for skid mounted reciprocating compressors.
6.3.2 Unless otherwise specified, the process design of the intercoolers and aftercoolers shall be
based on IPS-E-PR-750 "Process Design of Compressors" and the Appendix "C" thereof.
6.3.3 Not withstanding Clause 6.3.2 above, shell and tube heat exchangers shall be used for
intercooling and aftercooling and shall be in conformity with API 619, and API 680, on the following:
a) Water-cooled intercoolers and aftercoolers for nonflammable, nontoxic services (air, inert gas,
and so forth) shall be designed and constructed in accordance with the ASME Boiler and
Pressure Vessel Code. For flammable or toxic gas services, TEMA Class R heat exchangers
shall be furnished and shall be in accordance with API Standard 660 and Section VIII, Division 1
of the ASME Code.
b) Water shall be on the tube side of the heat exchanger.
c) Unless otherwise specified the water side of shell and tube exchanger shall be designed in
accordance with, Clause 6.2.7.5 of this Standard.
d) Intercoolers shall be mounted separately or on the machine, as specified by the Company.
e) Relief valves shall be provided on the process side of both intercoolers and aftercoolers.
f) Rupture discs on the shell side shall be furnished only when specified by the Company.
6.3.4 Intercoolers and aftercoolers shall be provided by the Vendor, with facilities to separate,
collect and discharge condensate through a continuous drainer. Condensate collection pots shall be
per the ASME Code, Section VIII or other pressure vessel code specified by the Company.
6.3.5 Air-cooled heat exchanger shall only be used for skid mounted compressor’s intercoolers and
aftercoolers upon the Company’s requirements and approval.
6.3.6 When air-coolers are specified by the Company, they shall conform either to API Standard
661, or shall be of Vendor’s standard. Vendor shall inform the Company on the advantages of
Vendor’s standard and shall acquire Company’s written approval.
6.3.7 Unless otherwise specified, air-cooled heat exchangers used for intercoolers and aftercoolers
shall have automatic temperature control. This control may be accomplished by louvers, variable
pitch fans, bypass valve or by any combination thereof. The proposed control systems shall be
approved by the Company.
6.3.8 Caution should be exercised because of the susceptibility of heat-exchangers and their
supporting structures to pulsation-induced vibration.
6.3.9 Thermometer wells should be located at the inlet and outlet of the intercoolers and aftercooler
and temperature reading should be taken at these points.

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APPENDICES

APPENDIX A

TYPICAL CLOSED COOLING WATER SYSTEM FOR MULTIPLE ENGINE INSTALLATIONS

Fig. A.1

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TYPICAL CLOSED COOLING WATER SYSTEM FOR RECIPROCATING COMPRESSORS

INTEGRAL WITH ENGINE, LUBRICATING OIL AND COMPRESSOR PACKING BOX COOLING
INSTALLATIONS
Fig. A.2

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APPENDIX B

CYLINDER COOLING SYSTEM

Fig. B.1

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 July 1994 IPS-E-PR-400

APPENDIX C

TYPICAL SELF-CONTAINED COOLING SYSTEM FOR PISTON ROD PRESSURE PACKING

Fig. C.1

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