ISO 10524:1995

1
INTERNATIONAL IS0
STANDARD 10524
First edition
1995-I 2-01
Pressure regulators and pressure
regulators with flow-metering devices
for medical gas systems
RBgulateurs de pression avec ou sans d6bitmGtre pour systgmes de gaz
mgdicaux
Reference number
IS0 10524: 1995(E)

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IS0 10524:1995(E)
Contents
Page
1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scope
1
Normative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Terminology and units of measurement
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Materials and cleanliness
. . . . . . . . . . . . . . . 5
Requirements for pressure gauges and flow-gauges
General requirements for pressure regulators, pressure regulators
with flowmeters, pressure regulators with flow-gauges, pressure
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
regulators with fixed orifices
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
8 Environmental temperatures
7
9 Special requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
IO Operating characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
11 Test methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
12 Marking .
........................................................... 19
13 Sealing and packaging
Information to be supplied by manufacturer with pressure
14
................................................................................ 19
regulator
............... 20
15 Information supplied by manufacturer on request
Annex
21
A Bibliography .
0 IS0 1995
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 the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii

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Q IS0
IS0 10524:1995(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
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.
International Standard IS0 10524 was prepared by Technical Committee
ISO/TC 121, Anaesthetic and respiratory equipment, Subcommittee
SC 6, Medical gas systems.
Annex A of this International Standard is for information only.

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0 IS0
IS0 10524:1995(E)
Introduction
Pressure regulators are widely used on medical gas cylinders to reduce
the high cylinder pressure to a lower pressure suitable for use with
medical equipment or for delivery of the gas directly to a patient. They
may be used to control pressure and flow supplied by a medical gas
pipeline system.
These functions cover a wide range of inlet and outlet pressures and flows
which require specific design characteristics for the appropriate regulator.
It is therefore important that the operating characteristics of the pressure
regulator be specified and tested in a defined manner.
Pressure regulators are normally coupled to devices which control the
flow, such as a flow-control valve or a fixed orifice; the flow may be indi-
cated by a flow-gauge or by a flowmeter.
It is essential that regular inspection and repair are undertaken to ensure
that the pressure regulators continue to meet the requirements of this
International Standard.
This International Standard pays particular attention to
-S afety ( mecha nical strength, safe relief of excess pressure and resist-
a nce to ignitio
n);
- cleanliness and suitability of materials;
- gas specificity;
- identification;
- testing;
info rmation supplied.

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IS0 10524:1995(E)
INTERNATIONAL STANDARD 0 IS0
Pressure regulators and pressure regulators with
flow-metering devices for medical gas systems
This International Standard also applies to the follow-
1 Scope
ing types of pressure regulators with flow-metering
devices:
d) pressure regulators with integral flow-metering
1 .I This International Standard specifies require-
devices as described in a) and c);
ments for pressure regulators and pressure regulators
with flow-metering devices intended for the adminis-
e) pressure regulators with flow-metering devices
tration of medical gases in the treatment, manage-
that are not integral with the types of pressure
ment, diagnostic evaluation and care of patients.
regulators described in a) and c) but are not in-
It applies to the types of pressure regulators given in
tended to be detached from the pressure regu-
a), b) and c) for use with the following medical gases:
lator by the user.
air
1.2 This International Standard does not apply to
carbon dioxide
helium
high-pressure and low-pressure regulators that are
a)
oxygen
an integral part of medical gas pipeline systems;
nitrogen
nitrous oxide
low-pressure regulators, with or without flow-
b)
xenon
metering devices, that are an integral part of
mixtures of oxygen and carbon dioxide
medical equipment;
mixtures of oxygen and helium
mixtures of oxygen and nitrogen
pressure regulators integrated within cylinder
d
mixtures of oxygen and nitrous oxide
va Ives;
The types of pressure regulators are as follows:
vacuum regulators.
d
a) high-pressure regulators (inlet pressure up to
20 000 kPa) intended to be connected by the user
2 Normative references
to high-pressure gas cylinders;
The following standards contain provisions which,
high-pressure regulators (inlet pressure up to
through reference in this text, constitute provisions
20 000 kPa) that are an integral part of medical
of this International Standard. At the time of publi-
equipment (e.g. anaesthetic machines, lung
cation, the editions indicated were valid. All standards
ventilators, resuscitators);
are subject to revision, and parties to agreements
based on this International Standard are encouraged
low-pressure regulators (inlet pressure up to
to investigate the possibility of applying the most re-
1 400 kPa) intended to be connected by the user
cent editions of the standards indicated below.
to terminal units of medical gas pipeline systems.
1

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0 IS0
IS0 10524:1995(E)
3.4 single-stage pressure regulator: Pressure
Members of IEC and IS0 maintain registers of cur-
regulator that reduces the inlet pressure in a single
rently valid International Standards.
stage to the required pressure.
IS0 7-l : 1994, Pipe threads where pressure-tight
joints are made on the threads - Part 1: Dimensions,
3.5 two-stage pressure regulator: Pressure regu-
tolerances and designation.
lator that reduces the inlet pressure in two stages to
the required pressure.
IS0 32:1977, Gas cylinders for medical use - Mark-
ing for identification of con tent.
3.6 flowmeter: Device that measures and indicates
the flow of a specific gas.
I SO 228-l : 1994, Pipe threads where pressure-tight
joints are not made on the threads - Part I: Dimen-
NOTE 1 It may incorporate a flow adjustment control.
sions, tolerances and designation.
3.7 flow-gauge: Gauge which measures pressure
IS0 261:--J), IS0 general-purpose me tic screw
differential using ambient pressure as the datum point
threads - General plan.
but which is calibrated in units of flow.
IS0 407: 1991, Small medical gas cylinders - Pin-
NOTE 2 The flow-gauge does not measure flow: it indi-
index yoke-type valve connections.
cates flow by measuring the pressure upstream of a fixed
orif ice.
IS0 554: 1976, Standard atmospheres for conditioning
and/or testing - Specifications.
3.8 pressure gauge: Gauge which measures and
indicates a pressure.
IS0 5145:1990, Cylinder valve outlets for gases and
- Selection and dimensioning.
gas mixtures
3.9 pressure regulator with flowmeter: Pressure
regulator equipped with a flowmeter to measure and
IS0 5171 :I 995, Pressure gauges used in welding,
indicate flow.
cutting and allied processes.
I SO 5359: I 989, Low-pressure flexible connecting as- 3.10 pressure regulator with flow-gauge: Press-
semblies (hose assemblies) for use with medical gas ure regulator which incorporates a flow-gauge and
systems. orifice downstream of the flow-gauge.
IS0 9170:1990, Terminal units for use in medical gas
3.11 pressure regulator with fixed orifice: Preset
pipeline systems.
pressure regulator which incorporates one or more
fixed orifices to control the flow.
3 Definitions 3.12 high pressure [HP]: Pressure greater than
1 400 kPa (14 bar).
For the purposes of this International Standard, the
following definitions apply.
3.13 low pressure [LPI: Pressure of 1 400 kPa
(14 bar) or less.
3.1 pressure regulator: Gas pressure reducing and
controlling device designed to provide a constant de-
3.14 pressure relief valve: Preset device designed
livery (downstream) pressure over a range of inlet
to relieve excess pressure at a preset value and pro-
pressures and flows.
tect the pressure regulator.
3.2 adjustable pressure regulator: Pressure regu-
3.15 rated (maximum) inlet pressure, P,: Rated
lator fitted with a means of user adjustment of the
(maximum) upstream pressure for which the pressure
delivery pressure under normal use.
regulator is designed.
3.3 preset pressure regulator: Pressure regulator
3.16 rated (maximum) outlet pressure, P,: Rated
not fitted with a means of user adjustment of the
(maximum) downstream pressure for the standard
delivery pressure under normal use and for which
discharge QI, specified in the operation and mainten-
tools are required to adjust the factory preset press-
ance manual.
ure.
1) To be published. (Revision of IS0 261:1973)
2

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0 IS0
IS0 10524:1995(E)
3.17 test inlet pressure; upstream critical press-
4 Terminology and units of
ure, P3: Minimum inlet pressure for the purpose of
measurement
rating the flow performance (standard discharge) of
the pressure regulator.
4.1 Typical examples of pressure regulators and as-
sociated components are shown in figure 1.
NOTE 3 It is equivalent to twice the maximum outlet
pressure, P2, plus 100 kPa, i.e. P3 = ZP, + 100 kPa.
4.2 Typical applications of pressure regulators are
shown in table 1.
3.18 closure pressure, Pa: Stabilized outlet pressure
4.3 Unless otherwise indicated, the units of
1 min after the cessation of the flow from a regulator
measurement are:
where the flow has been set to standard discharge.
pressure kPa
3.19 test outlet pressure, P,: Highest or lowest
flow
I/min
value of the outlet pressure resulting from a variation
0
in the inlet pressure between P, and P3 at previously
temperature C
adjusted conditions, P,, P,, Q,.
3.20 standard discharge, QI: Flow, specified in the
operation and maintenance manual, for which the
5 Materials and cleanliness
regulator is designed to maintain a rated outlet
pressure, P2, at test inlet pressure P3.
5.1 Materials
Metallic and non-metallic materials including lubri-
3.21 pressure characteristics: Variation of outlet
cants, thread sealants and sealant rings shall be
pressure with inlet pressure under constant flow
selected for the intended application and shall be
conditions.
compatible under operating conditions.
Extreme care should be used in the selection of ma-
3.22 flow characteristics: Variation of outlet press-
terials for use with a medical gas. Materials that react
ure in relation to the rate of flow from zero to the
normally in air may react violently in an oxygen-
maximum capacity flow of the regulator with the inlet
enriched atmosphere. Also mechanical thermal action
pressure remaining constant.
of the gas or gases being controlled should be con-
sidered during selection of material. Springs and other
3.23 gas-specific: Having characteristics which pre-
moving parts liable to come in contact with the
vent interchangeability and allow assignments to one
medical gas should not be p ated.
gas or vacuum service only.
5.2 Cleanliness
3.24 high-pressure regulator: Pressure regulator
All surfaces in contact with the medical gas shall be
intended for use with inlet pressure greater than
cleaned for oxygen service.
Any method of cleaning
1 400 kPa.
and degreasing may be used which effectively re-
moves all surface dirt and hydrocarbons without leav-
low-pressure regulator: Press ure regulator ing residues. Chemical cleaning methods will normally
3.25
h inlet press ure of 1 400 kPa or require a subsequent washing and drying process to
inten ded for use wit
remove the residues.
less.

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IS0 10524:1995(E)
8
1
-
3
15
5
a) Adjustable pressure regulator
b) Preset pressure regulator with flowmeter
8
\\\\\x\W\\\\ X Urnin
17
Z l/min
14
6
c) Adjustable pressure regulator with flow-gauge d) Preset Pressure reaulator with fixed orifices
Key
1 Body 7 HP gauge
13 Fixed orifice
2 Cover gauge
8 LP (or flow-gauge) 14 Pressure regulator valve
3 Inlet connector 9 Flowmeter
15 Inlet filter
4 Outlet connector 10 Valve spindle
16 Outlet valve
5 Pressure regulating spring 11 Relief valve
17 Hose nipple
6 Adjusting device 12 Control knob
Figure 1 - Typical examples of pressure regulators

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IS0 10524:1995(E)
Table 1 - Typical applications of pressure regulators
P, 1) P2 2)
Q 3’
1
Typical application
TYPe SUPPlY
kPa kPa I/min
Regulators 900 to 20 000 400 60 HP gas cylinders Single medical application 4)
Regulators 1 700 to 20 000 800 300 HP gas cylinders Single surgical tool
Regulators with
900 to 20 000 - 40 HP gas cylinders Single patient use
flowmeter
Regulators with flow- 900 to 20 000 - 20 HP gas cylinders Home care or emergency
gauge and fixed orifice transport
Regulators 400 to 1 400 - 60 Pipeline systems Single item of medical
equipment 4)
Regulators with
flowmeter 400 to 1 400 - 40 Pipeline system Single patient use
1) Range of inlet pressure
2) Outlet pressure
3) Maximum continuous flow
4) Some medical equipment may require higher flows for a short period of time.
NOTE 4 Pressure gauges cannot indicate the amount of
6 Requirements for pressure gauges
liquified gas contained in a cylinder.
and flow-gauges
7 General requirements for pressure
IS0 5171 applies with the following amendments.
regulators, pressure regulators
with flowmeters, pressure regulators
6.1 Dimensions
with flow-gauges, pressure regulators
with fixed orifices
The connecting thread for connecting the gauges to
the regulators shall comply with IS0 228-1, class B
(when parallel) or IS0 7-l (when tapered). The thread
7.1 Inlet connection
diameter shall be l/4”, l/8”, or Ml0 x 1 complying
with IS0 261. Nominal gauge sizes other than those
7.1.1 The inlet connection for a pressure regulator
specified in IS0 5171 are permitted.
connected to a gas cylinder shall conform to IS0 407,
IS0 5145 or the relevant national standard.
6.2 Scale reading
7.1.2 The inlet connection for a pressure regulator
connected to a terminal unit shall conform to
6.2.1 All markings on the scale of all pressure IS0 9170.
gauges and flow-gauges shall be legible to an operator
having a visual acuity, corrected if necessary, of 1, 7.1.3 The torque required to remove the inlet con-
seated or standing 1 m from the gauge at an
nection from the regulator body shall be not less than
illuminance of 215 lx.
30 N-m.
7.2 Outlet connection
6.2.2 For pressure gauges intended to indicate cyl-
inder contents, the scale shall either be numbered as
7.2.1 If the outlet connection is intended for user
specified in IS0 5171 or be marked for contents as
connection or disconnection, it shall be a DISS or a
0, l/4, l/2, 3/4, and full. In the latter case the maxi-
NIST body conforming to IS0 5359 or a quick-
mum operating pressure of the gauge shall be marked
connector socket conforming to IS0 9170.
on the dial.

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0 IS0
IS0 10524:1995(E)
an unforeseen increase of the operating temperature and
7.2.2 The torque required to remove the outlet con-
the fact that the ignition temperature is not a constant. In
nection from the regulator body shall be not less than
this connection, it must be emphasized again that values
20 N=m.
of the ignition temperature always depend on the test
method used, which does not exactly simulate all possible
7.3 Pressure relief valve
operating conditions.
7.3.1 A pressure relief valve shall be provided as a
7.6 Outlet valve
component part of a pressure regulator intended for
use with HP pressure cylinders to relieve excess
7.6.1 If a pressure regulator is fitted with an outlet
pressure. A bursting disc shall not be used as a relief
valve, the torque required to remove the valve from
valve.
the pressure regulator body shall be not less than
20 Nmm.
7.3.2 The pressure relief valve shall remain gas-tight
to a pressure above the maximum pressure Pz, taking
7.6.2 If a pressure regulator is fitted with an outlet
into account the coefficients i and R, as tested in
valve, the control knob and the valve spindle shall be
11.11.
captive such that they cannot be disengaged without
the use of a tool.
The relief valve should be fitted in such a way that the
disch arge will not endanger person nel.
gas
7.7 Pressure adjusting device
7.3.3 The minimum discharge, Q,,, of the relief valve
shall be equal to or greater than the standard dis-
7.7.1 The pressure adjusting device shall be captive
charge, Q,, at a pressure Prv = 2P,, as tested in
and shall be removable only by the use of a tool. The
11.11.
pressure regulator shall be designed so that the
regulator valve cannot be held in the open position as
a consequence of the pressure regulator spring being
7.4 Filtration
compressed to its solid length.
7.4.1 The pressure regulator shall incorporate on the
7.7.2 It shall not be possible to set a pressure at
high-pressure side upstream of the regulator valve a
which the relief valve lifts.
filter with openings no greater than 100 pm or equiv-
alent mesh.
7.8 Gas tightness
NOTE 5 Metallic filters such as sintered bronze filters
serve to retard the progress of the flame front in the event
Neither the external nor the internal leakage shall ex-
of ignition upstream of the pressure regulator.
teed IO ml/h when HP and LP chambers are sub-
jetted to their respective maximum rated pressure.
7.5 Resistance to ignition
The test is given in 11 .I 2.
7.5.1 HP pressure regulators shall not ignite when
7.9 Mechanical resistance
submitted to oxygen pressure shocks. The test is
given in 1 I .8.2 and 11.8.3.
7.9.1 The pressure regulator shall conform to the
operating characteristics given in clause IO after the
7.5.2 For pressure regulators for all medical gases
HP chamber of the pressure regulator has been
used on HP cylinders, each possible combination of
pressurized to I,5 times its rated inlet pressure, P,,
filters and pressure regulator assemblies rec-
for 5 min. The test is given in 11.9.1.
ommended by the manufacturer shall pass the ig-
nition test given in 11.8.2 and II .8.3.
7.9.2 The pressure regulator shall conform to the
operating characteristics given in clause IO after the
7.5.3 For LP pressure regulators, the ignition tem-
LP chamber of the pressure regulator has been
perature of the non-metallic components in contact
pressurized to twice its rated outlet pressure, Pp, for
with the gas, including the sealing materials and lu-
5 min. The test is given in 11.9.2.
bricants (if used), shall not be lower than 160 “C. The
test for the determination of the ignition temperature
7.9.3 The HP portion of the pressure regulator shall
is given in 11.8.3.
be capable of withstanding 2,25 times its rated inlet
pressure, P,, without rupturing. The test is given in
NOTE 6 This safety margin (100 “C above the maximum
operating temperature) is necessary because it covers both 11.9.3.
6

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0 IS0 IS0 10524:1995(E)
7.9.4 The LP portion of the pressure regulator shall
9 Special requirements
be capable of withstanding four times its rated outlet
without rupturing. The test is given in
pressure, P2,
11.9.4.
9.1 Requirements for pressure regulators
with flowmeter
7.10 Flow characteristics
9.1.1 Flow control valve
The flow characteristics shall correspond to within
+I0 % of the manufacturer’s published values. The
If a pressure regulator with flowmeter is fitted with a
test is given in 11.5.1.
flow control valve, the control knob and the valve
spindle shall be captive such that they cannot be dis-
engaged without the use of a tool.
7.11 Regulators for HP cylinders
The flow control valve shall be designed so that the
Pressure regulators intended to be used with high-
flow increases when the knob is turned counter-
pressure cylinders shall be fitted with a high-pressure
clockwise.
gauge.
9.1.2 Accuracy of flowmeter
7.12 Pressure gauges and f ow-gauges
The accuracy of the flow at any flow graduation of a
flowmeter shall be within + 10 % of the indicated
i-gauges shall meet
7.12.1 Pressure gauges and flo\
n value for flows between IO % and 100 % of full scale
the requirements given in clause 0.
or & 0,5 I/min, whichever is the greater.
For a flowmeter with a full scale of less or equal to
7.12.2 The torque required to remove the pressure
I I/min, the accuracy of the flow at any flow gradu-
gauge(s) and the flow-gauge from the pressure regu-
ation shall be within k 10 % of the indicated value.
lator body or from the outlet valve body shall be not
less than 20 Nmm.
The accuracy shall be measured at P, when the flow
is discharged into an ambient atmosphere of
101,3 kPa at an operating temperature of 23 “C. The
8 Environmental temperatures
test is given in 1 1 .I 3.
81 . Storage temperature
9.1.3 Scale and indicators of flowmeter
The pressure regulator shall be capable of being
The flowmeter shall be graduated in units of litres or
stored at temperatures of - 40 “C and + 70 “C for
millilitres per minute.
4 h each. After exposure to these temperatures, the
pressure regulator shall comply with the requirements
The scale of the flowmeter shall be legible to an op-
of this International Standard.
erator having visual acuity of 1, corrected if necessary,
seated or standing 1 m from the flowmeter at an
NOTE 7 There is no requirement to test the pressure
illuminance of 215 lx.
regulator function at the storage temperatures.
9.1.4 Pressure of flowmeter
8.2 Operating temperature
The flowmeter shall be capable of containing or safely
relieving a pressure of 2P,. The test is given in 11 .I 0.
8.2.1 Following exposure to the storage tempera-
Following this test the flowmeter shall meet the re-
tures as specified in 8.1, the pressure regulator shall
quirements given in 9.1.2.
function in accordance with the requirements of this
International Standard and the manufacturer’s specifi-
cations at operating temperatures of - 20 “C and
9.1.5 Removal of flowmeter
+60 “6.
The torque required to remove the flowmeter from
the pressure regulator body shall not be less than
8.2.2 The temperature requirement does not apply
20 N-m.
9.3.4, 10.1 and 10.2.
to 9.1.2, 9.2.2,

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IS0 10524:1995(E)
9.2 Requirements for pressure regulators
11 Test methods
with flow-gauges
11 .I General
92.1 The flow-gauge shall be marked in accordance
Checking conformity of a regulator of a given type
with 12.2.
consists of tests and checking of documents.
9.22 The flow shall be accurate to + 10 % of the
I I.2 Test samples and necessary documents
full scale or + 0,5 I/min, whichever is the greater. The
test is givenin 11 .I 4.
The manufacturer shall provide appropriate samples
complete with filter and the documentation for test
9.3 Requirements for pressure regulators purposes, as required by the test institute.
with fixed orifices
WARNING
- These tests can result in the liber-
ation of significant energy: safety precautions are
9.3.1 The pressure regulator shall be preset.
essential.
9.3.2 If a fixed orifice is intended to be removed, this I
11.3 rest conditions
shall require a tool and a torque of not less than
20 N=m and the body of the orifice shall be marked
11.3.1 General characteristics of test installation
with the corresponding flow in units of litres per min-
ute.
Except where otherwise stated, tests shall be carried
out at - 20 “C and + 60 “C.
9.3.3 If there are multiple orifices, the operating
All the pipelines of the test installation together with
torque required to change to or from the off position
the valve controlling the flow shall have a flow ca-
and from one setting to another shall be not less than
pacity greater than that of the pressure regulator to
0,5 N-m and not more than 5 Nmm.
be tested.
9.3.4 At the manufacturer’s specified preset press-
11.3.2 Test gas
ure, the flow shall be accurate to + 10 % of the stated
-
value or + 0,5 I/min, whichever is the greater. The
Tests shall be carried out according to IS0 554 with
test is given in 11 .I 4.
air or nitrogen free from oil and grease. Tests shall be
carried out with dry gas, a maximum moisture content
of 50 ppm at standard atmospheric pressure corre-
sponding to a dew point of - 48 “C.
10 Operating characteristics
If nitrogen or air is used, the flows shall be corrected
10.1 The irregularity coefficient, i, shall fall in the with the conversion coefficients given in table 2.
range of + 0,2. The test is given in 11.6.
-
EXAMPLE: Conversion for N,O
With a test gas nitrogen, and a measured flow of the
IO.2 At a flow equal to the standard discharge, QI,
the coefficient of pressure increase upon closure, R, test gas of 26 I/min, the calculated flow of
shall be less than 0,2. The test is given in 11.7. N,O = 26 x 0,796 = 20,696 I/min.
Table 2
- Conversion coefficients
Air
Test gas He Xe
02 N2 w co2
I,02 0,81 0,81 2,695 0,47
Air 1 0,95
I 0,46 I
Nitrogen I 0,983 0,93 I 1 I 0,796 0,796 I 2,65
I

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0 IS0
IS0 10524:1995(E)
11.3.3 Reference conditions of the pressure regulator stabilizes, whichever is the
greater. At the end of this period, operate and test the
Flow-measuring data shall be corrected to - 23 “C pressure regulator in accordance with 8.2.1.
and + lOI, kPa.
Il.4 Performance and functional tests
11.3.4 Test bench
11.4.1 These tests shall be carried out at ambient
The test bench shall be constructed in such a way temperature.
that the inlet and outlet pressures can be regulated
11.4.2 Equipment for the measurement of Q, is
separately. The equipment may be operated by re-
mote control. shown in figure2. The pressure regulator may be
supplied by a buffer cylinder. The upstream pressure
The gas supply for rated maximum inlet pressure, P,,
& is held constant by means of an auxiliary pressure
and test inlet pressure, & shall have sufficient ca-
regulator or any equivalent device. The test shall be
pacity (see figures 2 and 3).
carried out at the standard discharge Q, stated by the
manufacturer.
11.3.5 Temperature stabilization
With the outlet control valve closed, apply an inlet
pressure of & Set the outlet pressure to P,. Gradually
Store the pressure regulator in the environmental
open the outlet control valve until the standard dis-
chamber at - 20 “C for 4 h or until the temperature
charge Q, is attained. If the outlet pressure has de-
of the pressure regulator stabilizes, whichever is the
creased, readjust to the value & on an adjustable
greater. At the end of this period, operate and test the
pressure regulator. (This is not possible with a preset
pressure regulator in accordance with 8.2.1.
pressure regulator.) A disch
...