ISO 10438-3:2003

INTERNATIONAL ISO
STANDARD 10438-3
First edition
2003-12-15
Petroleum, petrochemical and natural gas
industries — Lubrication, shaft-sealing
and control-oil systems and auxiliaries —
Part 3:
General-purpose oil systems
Industries du pétrole, de la pétrochimie et du gaz naturel — Systèmes
de lubrification, systèmes d'étanchéité, systèmes d'huile de régulation
et leurs auxiliaires —
Partie 3: Systèmes d'huile pour applications générales

Reference number
©
ISO 2003
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2003
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2003 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms. 1
4 Minimum components. 2
5 General. 2
6 Baseplates . 4
7 Oil reservoirs . 4
8 Pumps and drivers. 8
9 Coolers. 11
10 Filters. 13
11 Transfer valves. 15
12 Lube-oil rundown tanks. 15
13 Piping . 15
14 Instrumentation and electrical systems . 16
15 Inspection, testing, and preparation for shipment . 16
16 Vendor's data. 18
Annex A (informative) Typical schemas for general-purpose oil systems. 20
Annex B (informative) General-purpose oil system data sheets. 25
Annex C (informative) Inspector's check list. 33
Annex D (informative) Technical data for cost estimating of general-purpose oil systems . 36
Bibliography . 38

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 10438-3 was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore structures
for petroleum, petrochemical and natural gas industries, Subcommittee SC 6, Processing equipment and
systems.
ISO 10438 consists of the following parts, under the general title Petroleum, petrochemical and natural gas
industries — Lubrication, shaft-sealing and control-oil systems and auxiliaries:
 Part 1: General requirements
 Part 2: Special-purpose oil systems
 Part 3: General-purpose oil systems
 Part 4: Self-acting gas seal support systems
iv © ISO 2003 – All rights reserved

Introduction
ISO 10438 is based on API Std 614, 4th edn., April 1999, divided into four parts as follows:
 Part 1: General requirements is based on Chapter 1 of API Std 614;
 Part 2: Special-purpose oil systems is based on Chapter 2 of API Std 614;
 Part 3: General-purpose oil systems (this part) is based on Chapter 3 of API Std 614;
 Part 4: Self-acting gas seal support systems is based on Chapter 4 of API Std 614.
Users of this part of ISO 10438 should be aware that further or differing requirements might be needed for
individual applications. This part of ISO 10438 is not intended to inhibit a vendor from offering, or the
purchaser from accepting alternative equipment or engineering solutions for the individual application. This
may be particularly appropriate where there is innovative or developing technology. Where an alternative is
offered, the vendor should identify any variations from this part of ISO 10438 and provide details.
This part of ISO 10438 requires the purchaser to specify certain details and features.
A bullet (•) at the beginning of a clause or subclause indicates that either a decision is required or further
information is to be provided by the purchaser. This information or decision should be indicated on suitable
data sheets; otherwise it should be stated in the quotation request (inquiry) or in the order.

INTERNATIONAL STANDARD ISO 10438-3:2003(E)

Petroleum, petrochemical and natural gas industries —
Lubrication, shaft-sealing and control-oil systems and
auxiliaries —
Part 3:
General-purpose oil systems
1 Scope
This part of ISO 10438 specifies requirements for oil systems supplying lubricating oil to machines in general-
purpose applications for use in the petroleum, petrochemical and natural gas industries as well as in other
industries by agreement. It is intended to be used in conjunction with ISO 10438-1. ISO 10438 in its entirety
specifies requirements for lubrication systems, oil-type shaft-sealing systems, self-acting gas seal systems,
control-oil systems and other auxiliaries for general- or special-purpose applications. These systems can
serve equipment such as compressors, gears, pumps and drivers. General-purpose applications are limited to
lubrication systems.
None of the parts of ISO 10438 is applicable to internal combustion engines.
Typical schemas for general-purpose oil systems are provided in Annex A.
NOTE General-purpose systems supply lubricating oil only (i.e. no seal oil) and do not require an accumulator to
cover transient conditions.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 10438-1:2003, Petroleum, petrochemical and natural gas industries — Lubrication, shaft-sealing and
control-oil systems and auxiliaries — Part 1: General requirements
ISO 14691, Petroleum and natural gas industries — Flexible couplings for mechanical power transmission —
General purpose applications
IEC 60079 (all parts), Electrical apparatus for explosive gas atmospheres
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms, definitions and abbreviated terms given in ISO 10438-1 apply.
4 Minimum components
The bill of material covered below describes the minimum specified system. Manufacturers may substitute
alternatives for any of the options covered in this clause as upgrades to the basic system if required or if
offered as standard for the equipment serviced. In any event, the oil system supplied shall be capable of
supplying sufficient quantities of clean, filtered oil at proper temperature and pressure for start-up and all
operating conditions of the serviced rotating equipment.
The basic oil system shall contain as a minimum the following components:
a) single pump, (cast iron or steel casing) which may be shaft-driven or motor driven;
b) motor driven start-up pump (if required);
c) valves, made of carbon steel with stainless steel trim;
d) oil piping, made of stainless steel with carbon steel slip-on flanges, conforming to the piping system
design code (e.g. ASME B31.3), or stainless steel tubing and fittings;
e) reservoir, made of stainless steel with minimum 3 min retention time, or combined with equipment base;
f) single cooler;
g) single filter with 25 µm nominal pore size;
h) single regulator for control of delivered oil pressure;
i) the following instruments:
1) pressure indicator (PI),
2) temperature indicator (TI),
3) visual level indicator (LI),
4) pressure switch low-low (PSLL).
5 General
5.1 The equipment (including auxiliaries) covered by this part of ISO 10438 shall be designed and
constructed for a minimum service life of 20 years. It is recognized that this is a design criterion.
5.2 The oil system shall be suitable for general-purpose applications as defined in ISO 10438-1. The
system shall be designed as a separate console, or may be designed to be integral with the baseplate of the
equipment it serves. If components are spared, the design shall allow for transfer between and shutdown of
the main and spared components of the system for maintenance without interrupting the operation of the
system or the equipment the system serves.
5.3 The vendor shall assume unit responsibility for all equipment and all auxiliary systems included in the
scope of the order.
5.4 The materials of construction of all major components shall be clearly stated in the vendor's proposal.
Materials shall be identified by reference to applicable international or national standards including the
material grade.
5.5 The purchaser shall specify the required oil supply conditions and the heat load.
2 © ISO 2003 – All rights reserved

z 5.6 Control of the sound pressure level (SPL) of all equipment furnished shall be a joint effort of the
purchaser and the vendor. The equipment furnished by the vendor shall conform to the maximum allowable
sound pressure level specified by the purchaser.
5.7 Where oil is supplied from a common system to two or more machines (such as a compressor, a gear,
and a motor), the oil's characteristics shall be specified on the data sheets (such as provided in Annex B) on
the basis of mutual agreement with all vendors supplying equipment served by the common oil system.
NOTE The usual lubricant employed in a common oil system is a hydrocarbon oil of viscosity grade 32 or 46 as
specified in ISO 8068.
5.8 The system shall be designed to supply oil to all equipment specified by the purchaser.
5.9 Oil recycled for control purposes shall originate upstream of the filters.
NOTE This is to minimize the potential for generation of static electricity (or a static charge) that can result when
filtered oil bypasses the equipment and is recycled directly to the reservoir.
z 5.10 The purchaser shall specify whether the installation is indoors (heated or unheated) or outdoors (with or
without a roof) as well as the weather and environmental conditions in which the equipment will operate
(including maximum and minimum temperatures and unusual humidity, dust, or corrosion conditions).
z 5.11 If specified, the arrangement of the equipment, including piping and auxiliaries, shall be developed
jointly by the purchaser and the vendor. The arrangement shall provide adequate clearance areas and safe
access for operation and maintenance.
NOTE For some pre-engineered general-purpose oil systems, purchaser input might be impractical.
z 5.12 If applicable, the purchaser shall specify minimum requirements for clearance around and access to
components (especially clearance around and access to coolers, filters, and hand valves).
5.13 Motors, electrical components, and electrical installations shall be suitable for the area classification
(class, group, and division or zone) specified on the data sheets and shall meet the requirements of the
applicable part(s) of IEC 60079 as well as local codes specified and furnished by the purchaser (see
ISO 10438-1).
z 5.14 If specified, pumps, filters, strainers, coolers, traps, valves, and all other components that retain oil
under pressure and that are external to the reservoir shall be made of steel.
5.15 Unless otherwise specified, components may be submerged in the reservoir, and these may be made
of cast iron.
z 5.16 If specified, valved vents, drains, and piping shall be furnished to permit draining, cleaning, and refilling
of idle components while the equipment is in operation.
5.17 Coolers, filters, overhead rundown tanks, and other pressure vessels within the scope of the pressure
design code shall conform to the requirements of that code.
5.18 The vendor shall advise the purchaser of, and both parties shall mutually agree upon, any special
provisions that are necessary to ensure that an adequate supply of lube oil is maintained in the event of
complete failure of the lube-oil supply system. These provisions may include stand-by pumps, rundown tanks,
and special arrangements for equipment safety and protection when the equipment decelerates. Provisions
shall be adequate for coast-down time and cool-off time as applicable. The purchaser and the vendor shall
mutually agree upon the system and its components.
5.19 Block valves which interrupt the oil flow to the equipment shall not be installed in oil supply lines
downstream of the filters unless the block valves are part of a component block and bypass arrangement.
5.20 Welding of piping and pressure-containing parts, as well as any dissimilar-metal welds and weld repairs,
shall be performed in accordance with the pressure design code or the piping system design code as
applicable.
5.21 When components, which may require later removal for maintenance, are installed using screwed
connections, the connecting piping shall be provided with flanges such that the component may be removed
without requiring cutting pipe or major disassembly of the unit.
6 Baseplates
6.1 The major components (pumps, filters, coolers, and reservoir) shall be mounted directly on structural
steel as a separate console or integrated with the equipment base.
6.2 Unless otherwise specified, console baseplates shall be of the drip-rim type with one or more drain
connections at least DN40 (NPS 1 1/2) in size. Baseplates, mounted components, and decking shall be
arranged and installed to ensure drainage and avoid the retention of liquid.
6.3 The baseplate shall be provided with lifting lugs for at least a four-point lift. The baseplate shall be
designed so that after the components and all piping mounted on it are drained of oil, the package can be
lifted without permanently distorting or otherwise damaging either the baseplate or any component mounted
on it.
z 6.4 If specified, metal decking covering all walk and work areas shall be provided on the top of the
baseplate. If furnished, metal decking shall be non-skid.
z 6.5 If specified, baseplates shall be suitable for grouting.
z 6.6 If specified, the baseplate shall be suitable for column mounting (that is, of sufficient rigidity to be
supported at specified points) without continuous grouting under structural members. The baseplate design
shall be mutually agreed upon by the purchaser and the vendor.
z 6.7 If specified, all welding other than that covered by the pressure design code or the piping system design
code, such as welding on baseplates, non-pressure ducting, lagging, and control panels, shall be performed in
accordance with a structural welding standard (e.g. AWS D1.1).
6.8 The bottom of the baseplate between structural members shall be open. When the baseplate is
installed on a concrete foundation and grouted as specified in 6.5, accessibility for grouting under all load-
carrying structural members shall be provided.
7 Oil reservoirs
7.1 General
Reservoirs shall be separate or combined with the equipment baseplate, and they shall be rigid enough to
prevent sagging and vibration. Components bolted to the reservoir shall be mounted on pads; no bolt holes
shall extend into the reservoir.
7.2 Protection from dirt and water
Reservoirs shall be sealed to prevent dirt and water from entering. Top-surface openings shall be raised at
least 6 mm (1/4 in) and shall have a gasket. When pumps, coolers, or filters are mounted on top of the
reservoir, the reservoir top shall be provided with a drain rim or gutter and one or more drain connections.
4 © ISO 2003 – All rights reserved

7.3 Oil connections and internal piping
7.3.1 All oil return flow streams shall be hydraulically located as far away from the pump suction
connections as possible.
NOTE The use of the term “hydraulically located as far away” is intended to convey the concept that return flow
streams can be directed by internal piping or baffling to avoid disturbing the oil flow at pump inlets. This internal piping or
baffling could be used in lieu of external connections physically located such a distance from the pump suctions that they
avoid disturbing the oil flow at the pump inlets.
7.3.2 All atmospheric oil return connections (including fill connections) shall be located above the maximum
operating level and shall transport oil (via open-top stilling tubes or degassing trays). Stilling tubes shall have
bottom baffles.
7.3.3 Pump suction connections shall be located at least 50 mm (2 in) above the reservoir bottom.
7.3.4 Reservoir pipe connections DN40 (NPS 1 1/2) and larger shall be flanged.
7.4 Manways and drains
7.4.1 Each reservoir shall be furnished with a valved drain connection.
7.4.2 Manway openings shall be provided which will permit unobstructed access for inspection and cleaning
of all interior compartments. Manways shall be located on top of the reservoir and if entry is required for
cleaning each manway shall be at least 600 mm × 600 mm (24 in × 24 in). If access is not required for
cleaning, a minimum 150 mm (6 in) diameter opening shall be provided.
z 7.4.3 If specified, to ensure complete drainage, the bottom of each reservoir shall be sloped to a low point
drain.
z 7.4.4 If specified, a flanged drain connection (with a valve and a blind flange) at least 50 mm (2 in) in size
shall be provided.
7.5 Features and appendages
z 7.5.1 The oil reservoir shall have the following features and appendages:
a) the capacity to settle moisture and foreign matter adequately and to provide allowance for rundown from
the entire system;
b) provisions to eliminate air and minimize migration of foreign matter to each pump suction;
c) a reservoir level indicator such as a dipstick, level gauge, or bull’s eye;
d) if specified, an oil level glass arranged to cover the span from at least 25 mm (1 in) above the rundown
level to 50 mm (2 in) below the pump suction-loss level. The oil level glass shall be located as far away as
possible from the oil return lines and be visible from the perimeter of the unit. The maximum and
minimum operating levels, rundown level, and suction-loss level shall be indicated on the glass. If more
than one level glass is provided, they shall be offset. The top glass shall be of the weld pad type;
e) a weatherproof, corrosion-resistant filter-breather cap at least 50 mm (2 in) in size (this connection may
also be used as a fill opening);
f) if specified, a fill opening at least 50 mm (2 in) in size which automatically closes (normally held shut by a
spring) and is equipped with a stainless steel fine-mesh strainer basket that has an open area equal to
200 % of the internal pipe area;
g) internal baffles that are not gas-tight;
h) Individual non-pressurized reservoir return lines that enter the reservoir above the rundown level
(see 7.6.1.1);
i) if specified, a low-level alarm which actuates at the minimum operating.
7.6 Capacity and configurations
7.6.1 Definitions of levels
7.6.1.1 The rundown level (1 in Figure 1) is the highest level that oil in the reservoir may reach when the
entire system is shut down.
7.6.1.2 The maximum operating level (2 in Figure 1) is the highest level that oil will reach during normal
operation of the equipment.
7.6.1.3 The minimum operating level (3 in Figure 1) is the lowest level that oil will reach during normal
operation of the equipment.
7.6.1.4 The suction-loss level (4 in Figure 1) is the level at which the pump begins to lose prime. The
pump suction level is defined by the pump suction vortex and net positive suction head requirements.
7.6.1.5 The charge capacity is the total volume below the rundown level.
7.6.1.6 The normal operating range is any level between the maximum and minimum operating levels.
7.6.1.7 The retention capacity is the total volume below the minimum operating level.
7.6.1.8 Retention time is the time allowed for disengagement of entrained air or gas.
7.6.1.9 The rundown capacity is the volume between the rundown level and the maximum operating level.
7.6.1.10 The working capacity is the volume between the minimum operating level and the suction-loss
level.
7.6.2 Criteria for sizing
7.6.2.1 The working capacity between the minimum operating level (3 in Figure 1) and the suction-loss
level (4 in Figure 1) shall be sufficient for at least 3 min of normal flow.
7.6.2.2 The minimum retention capacity shall be defined as 3 min of normal oil flow.
7.6.2.3 The rundown capacity shall allow for all of the oil contained in all of the components, bearings
housings, rundown tanks, control elements, and vendor-furnished piping that drain back to the reservoir. The
rundown capacity shall also allow for at least an additional 10 % of these volumes for the purchaser's
interconnecting piping.
NOTE Rundown can cause some backup in the drain lines entering the reservoir.

6 © ISO 2003 – All rights reserved

Dimensions in millimetres (inches)

Key
1 rundown level 5 pump suction level
2 maximum operating level 6 alternative pump suction arrangements
3 minimum operating level 7 manufacturer's standard glass length
4 suction-loss level
A manufacturer's standard gauge glass may be used in this arrangement, with the bottom of the gauge no
less than 50 mm below the minimum operating level and with any excess length being above maximum
operating level.
Figure 1 — Reservoir levels and oil level glass details
7.7 Heating
z 7.7.1 The purchaser shall specify if an electric heater is required.
7.7.2 When an electric heater is specified, a thermostatically controlled removable electric immersion
heating element shall be provided for heating the charge capacity of oil before start-up in cold weather. The
device shall have the capacity to heat the oil in the reservoir from the specified minimum site ambient
temperature to the manufacturer's required start-up temperature within 12 h. Heater elements in contact with
the oil shall be sheathed in austenitic stainless steel; copper or copper-bearing materials shall not contact the
oil.
Electric immersion heaters should be interlocked by the purchaser to be de-energized when the oil level drops
below the minimum operating level.
7.7.3 When electric heaters are specified, they shall have a maximum surface heat flow density of 2 W/cm
(15 W/in ).
7.7.4 Electric heaters may be in direct contact with the reservoir oil when sized according to 7.7.3.
7.7.5 In all installations, but especially if top-mounted vertical or angle heaters are used, the heater element
shall be located below the pump suction loss level.
7.8 Provision for insulation
z If specified, reservoirs shall be fitted with insulation clips. The purchaser shall furnish and install the insulation.
7.9 Auxiliary connections
z If specified, each reservoir shall be provided with one threaded and plugged connection at least DN25
(NPS 1) in size above the rundown oil level. This connection may be used for such services as purge gas,
makeup oil supply, and oil conditioner return.
7.10 Special features
z 7.10.1 If specified, an easily accessible ladder with extended handrails and non-skid working surface shall be
provided.
z 7.10.2 If specified, handrails around the perimeter of the reservoir top shall be provided.
z 7.10.3 If specified, surface decking shall be provided. Surface decking shall be non-skid.
7.10.4 For equipment mounted on the reservoir, the reservoir shall provide sufficient structural stiffness to
properly support the equipment.
7.11 Materials
7.11.1 Unless otherwise specified, reservoirs and all appendages (except ladders and handrails) welded to
reservoirs shall be fabricated from austenitic stainless steel. Pipe connections shall be as specified in
Clause 13.
7.11.2 Where reservoirs are integral with equipment or equipment baseplates, and where stainless steel
inserts or cladding is not practical, coated carbon steel is acceptable if approved by the purchaser.
7.12 Grounding
Reservoirs shall be grounded either by grounding clips attached to the reservoir (for free-standing reservoirs)
or through the attached base structure. In either case, two grounding clips or pads diagonally opposed to each
other are required. The pads shall accommodate a 13 mm (1/2 in UNC) bolt.
8 Pumps and drivers
8.1 As a minimum, the oil system shall include an oil pump suitable for continuous operation. A horizontal
or vertical inline centrifugal, or a rotary positive displacement pump, as specified, shall be supplied.
8.2 Each pump shall have its own driver.
8.3 Unless otherwise specified, the main oil pump (unless it is shaft driven) shall be motor driven.
If primary and stand-by pumps are motor driven, it is recommended that the purchaser shall supply electric
feeds from independent sources.
NOTE Stand-by pumps are always motor driven due to relatively long start-up times for turbine-driven pumps.
8 © ISO 2003 – All rights reserved

z 8.4 If specified, a turbine-driven pump shall be supplied as the main oil pump. If specified, and when a
shaft-driven pump is supplied, an electric-driven stand-by pump shall be provided for start-up and main pump
failure backup
8.5 Motors shall comply with the standards specified by the purchaser. Flanged motors may be used for
motors below 7,5 kW (10 hp).
8.6 The minimum criteria given in a) to c) below shall be used when sizing pumps.
a) In all cases, pumps shall be sized to deliver the required capacity when pumping lube oil at the highest
temperature and the corresponding minimum viscosity (see 8.8).
b) Each pump (main or stand-by) shall be capable of supplying the normal oil flow required by the
equipment plus 20 % of the normal oil flow and supplying transient oil requirements.
c) Rotary pumps shall be capable of passing the total flow, as established in b), at the pressure-limiting
valve set pressure while not exceeding 90 % of the pump manufacturer's maximum differential pressure
rating at the minimum operating viscosity. The pump shall also be capable of operating continuously at
the normal flow, relief-valve set pressure, and minimum operating viscosity.
NOTE This selection criterion is required to avoid pump rotor contact during operation under extreme conditions.
8.7 The normal operating capacity of the centrifugal pumps shall be within 50 % to 110 % of their best
efficiency point. From their normal operating point to shutoff, centrifugal pumps shall have a continuous rise in
head of at least 5 % and, with the installation of a new impeller, shall be capable of a future increase in head
of at least 10 %.
8.8 Pump drivers shall be sized in accordance with a) or b) as applicable.
a) Centrifugal pumps shall deliver the specified system pressure across the pump's stable flow range when
the temperature of the pumped oil is 10 °C (50 °F).
b) Rotary pumps shall be capable of operating at the specified pump pressure-limiting valve setting
(including accumulation) when the temperature of the pumped oil is 10 °C (50 °F).
8.9 Check valves shall be provided on each pump discharge to prevent the flow of oil backwards through a
stand-by or idling pump.
8.10 For rotary pump systems, the vendor shall furnish external pressure-limiting valves that shall be
installed on the pump or in the piping supplied by the vendor. This valve shall not be used for pressure control.
Pressure-limiting valve settings, including an allowance for no more than 10 % accumulation, shall be
determined after all of the possible equipment and component failures are considered. The settings shall
protect the oil system components and piping. Fully accumulated pressure shall not exceed 110 % of the
design pressure.
8.11 Pressure-limiting valves when provided, shall be pressure-modulating devices (as opposed to
snap-acting or pop-type safety relief valves) with a pressure increase proportional to flow above the
valve-cracking pressure (that is, the pressure at which the valve begins to open). These devices shall be
mounted external to the reservoir and shall operate smoothly, without chattering and without causing a drop in
supply pressure to the equipment. Pressure-limiting valve piping shall be sized for the full flow of each pump;
the valves shall not chatter and the piping shall not vibrate. The minimum pressure-limiting-valve cracking
pressure shall be 10 % or 170 kPa (1,7 bar) (25 psi) higher than the highest required operating pressure,
whichever is greater. To avoid unnecessary delay in opening, pressure-limiting valves shall be located as
close to the oil pump discharge as possible at an elevation as near to or below the minimum operating level as
possible.
8.12 The oil system shall be provided with pressure-regulating devices that prevent fluctuation of the oil
pressure to the equipment when both the main and the stand-by pump are in operation or when either the
main or the stand-by pump is in operation and the other pump is started, brought up to operating speed, or
stopped. Each device shall have an adequate response time and shall operate smoothly without hunting,
chattering, or producing pressure or flow transients that can cause the equipment to shut down [see
15.3.3.8 e)]. These pressure-regulating devices shall be located so that an excessive rise in oil temperature
resulting from recirculation of uncooled oil is avoided (see, for example, Figure A.3).
System pressure regulating valve(s) shall be sized to pass the excess flow when one and/or both pumps are
in operation.
8.13 All pumps (except shaft-driven pumps) shall be installed with flooded suctions to ensure self-priming
and shall be installed with suction block valves (unless the pumps are inside the reservoir) and with discharge
block and check valves. Vertically mounted pumps shall be continuously vented to assure the entire pump
remains flooded. Shaft-driven pumps shall have adequate provision for priming and be of positive
displacement design. Suction piping shall be continuously vented or arranged to avoid pockets in which air
can accumulate or become trapped. Each pump shall have a separate suction line from the reservoir. The
pump suction lines shall be designed to avoid excessive piping loads on the pump casing flanges. Designs for
suction piping, suction block valves, pump casings, and all other components shall avoid the possibility of
overpressure caused by leaking discharge check valves.
z 8.14 If specified, for the protection of externally mounted centrifugal pumps during flushing and for the initial
operation of new oil systems, a removable strainer that is made from austenitic stainless steel and has an
open flow area equal to 150 % of the cross-sectional area of the suction pipe shall be installed in the suction
piping of each pump between the pump suction flange and the block valve. The temporary strainer shall be
identified by a protruding tab and shall have a mesh size adequate to stop all objects that would be injurious to
the pump. The piping arrangement shall permit the removal of the strainer without disturbing the alignment of
the pump. The strainer may be cone, basket, or Y-type.
8.15 Unless otherwise specified, for externally mounted rotary pumps, a permanent Y-type strainer with an
austenitic stainless steel basket that has an open flow area equal to 150 % of the cross-sectional area of the
suction pipe shall be installed in the suction piping of each pump. The strainer shall have a mesh size capable
of stopping all objects that would be injurious to the pump.
8.16 If a stand-by pump is furnished (8.4), in order to maintain satisfactory system operation when the main
pump fails to meet system requirements, the vendor shall furnish an automatic start-up control for the
stand-by oil pump. The start-up control of the stand-by pump shall be actuated by low oil supply pressure.
Motor control centres shall be provided by the purchaser. The control system shall have a manual reset.
8.17 Removable coupling guards shall be furnished.
8.18 Couplings shall be in accordance with ISO 14691. A non-spacer elastomeric coupling is acceptable for
power ratings up to 22 kW (30 hp).
8.19 Couplings and coupling-to-shaft junctures shall be rated for at least the maximum driver power
(including any motor service factor).
8.20 To assure that the connected machinery is accurately aligned, the total indicator reading of coupling
registration and alignment surfaces shall be controlled within specific limits. For all pumps, the coupling
surfaces normally used for checking alignment shall be concentric with the axis of coupling hub rotation within
the following limits: 13 µm (0,000 5 in) total diameter, with a minimum applicable tolerance of 25 µm (0,001 in)
total indicator reading and a maximum of 75 µm (0,003 in) total indicator reading. All other diameters not used
for location, registration, or alignment shall be to the coupling manufacturer's standard, provided balance
requirements are met.
8.21 For drivers larger than 7,5 kW (10 hp), mounting plates shall be provided as specified as follows.
z a) If specified, mounting pads shall be provided for each pump and its driver. Pads shall be larger than the
feet of the mounted equipment so as to allow for levelling of the console or package baseplate without
10 © ISO 2003 – All rights reserved

removal of the equipment. The pads shall be fully machined flat and parallel. Corresponding surfaces
shall be in the same plane within 150 µm/m (0,002 in/ft) of distance between the pads.
b) Pumps and drivers shall be mounted on a machined surface. All pads for drivers shall be machined to
allow for the installation of shims. Shims, at least 3 mm (1/8 in) thick, shall be placed under the feet of
each component. If the vendor mounts the components, a set of stainless steel shims at least 3 mm
(1/8 in) thick shall be furnished.
c) To minimize misalignment of the pump and driver shafts due to piping load effects, the pump and its
baseplate shall be constructed with sufficient structural stiffness to limit total misalignment to the values
specified in 8.20.
d) If mounted on the console without a baseplate, the pump shall be mounted on a structural support.
e) Transverse alignment positioning jackscrews shall be provided for each driver that weighs more than
200 kg (450 lb). Axial alignment positioning jackscrews shall be provided for each driver weighing more
than 400 kg (900 lb). The lugs holding these positioning screws shall be attached to the baseplate so that
the lugs do not interfere with the installation or removal of the component. Alignment positioning screws
shall be at least the same size as the jackscrews furnished with each component. To prevent distortion,
machining of mounting pads shall be deferred until welding on the baseplate in close proximity to the
mounting pads has been completed.
9 Coolers
9.1 A single oil cooler shall be provided if required to maintain oil supply temperature at 50 °C (120 °F).
Further provisions are as follows.
a) Coolers, if required, shall be in accordance with the requirements specified in d) and e), and, unless
otherwise specified, shall be shell-and-tube type.
z b) If specified, a plate-type or air-cooled cooler shall be supplied. The vendor shall include in the proposal
complete details of any proposed air-cooled or plate-frame cooler.
z c) If specified, the vendor shall supply connections for installation of the purchaser's air-cooled oil cooler(s)
mounted off the oil console.
d) The vendor shall supply all relevant data such as heat load and oil flow.
e) Pressure drop criteria for the oil side shall be mutually agreed between the vendor and purchaser.
f) Unless otherwise specified for duplex cooler arrangements, the equalization/fill valve shall be locked or
car-sealed in the open position with the equalization/fill line orifice thermal sized by the vendor to provide
thermal overprotection.
z g) If specified, for duplex cooler arrangements, the vendor shall provide thermal over-pressure protection of
the oil side of the coolers by providing separate thermal relief valves.
z 9.2 If specified, a cooling water system or systems shall be designed for the following conditions:
Velocity over heat-exchange surfaces 1,5 m/s to 2,5 m/s (5 ft/s to 8 ft/s)
Maximum allowable working pressure (p ), gauge W 690 kPa (6,9 bar) (W 100 psi)
MAW
Test pressure W 1,5 × p , gauge W 1,04 MPa (10,4 bar) (W 150 psi)
MAW
Maximum pressure drop 100 kPa (1 bar) (15 psi)
Maximum inlet temperature 30 °C (90 °F)
Maximum outlet temperature 50 °C (120 °F)
Maximum temperature rise 20 K (30 °F)
Minimum temperature rise 10 K (20 °F)
2 2
Fouling factor on water side 0,35 m ⋅K/kW (0,002 h⋅ft ⋅°F/Btu)
Provision shall be made for complete venting and draining of the system or systems.
The vendor shall notify the purchaser if the criteria for minimum temperature rise and velocity over
heat-exchange surfaces result in a conflict. The criterion for velocity over heat-exchange surfaces is intended
to minimize water-side fouling; the criterion for minimum temperature rise is intended to minimize the use of
cooling water. The purchaser shall approve the final selection.
9.3 Oil coolers shall have the following characteristics.
a) Each oil cooler shall maintain the lube-oil supply temperature at or below 50 °C (120 °F).
b) Each cooler shall be sized to accommodate the total cooling load.
c) Oil coolers shall not be located inside the reservoir.
d) In addition to the requirements of a) to c), shell-and-tube coolers shall be in accordance with the following.
z 1) If specified, a removable-bundle design is required for shell-and-tube coolers with more than 0,5 m
(5 ft ) of heat transfer surface.
2) Removable-bundle coolers shall be in accordance with the standards specified by the purchaser.
3) Coolers shall be constructed with a removable channel cover.
4) Unless otherwise specified, tubes shall be of a standard wall thickness and shall have an outside
diameter of at least 9 mm (3/8 in).
NOTE For oil systems that are cooled by open-cooling tower circulation and where it is likely that the cooling water
is contaminated by large particles, the purchaser might wish to require 16 mm (5/8 in) minimum tube size to prevent
rapid fouling of the tubes.
5) Water shall be on the tube side of the cooler.
z 6) If specified, the oil-side operating pressure shall be higher than the water-side operating pressure.
NOTE If selected for a general-purpose oil system, the possible result of this requirement is that the oil-pump
discharge pressure will be well above the lubricated equipment required oil pressure.
7) Unless otherwise specified, fin tubes or extended surface tubes are allowed.
z 9.4 If specified, and in addition to the requirements specified in 9.3, a) to c), plate-type coolers shall have
plates of austenitic stainless steel, or as specified by the purchaser.
z 9.5 If specified, and in addition to the requirements of points 9.3, a) to
...