ISO/DIS 10524-4

Pressure regulators for use with medical gases

Régulateurs de pression pour systèmes de gaz médicaux

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD ISO/DIS 10524-4
ISO/TC 121/SC 6 Secretariat: ANSI
Voting begins on Voting terminates on
2001-05-17 2001-10-17

INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • • ORGANISATION INTERNATIONALE DE NORMALISATION

Pressure regulators for use with medical gases —
Part 4:
Low-pressure regulators intended for incorporation into
medical equipment
Régulateurs de pression pour systèmes de gaz médicaux —

Partie 4: Régulateurs de pression à faible pression destinés à être incorporés dans du matériel médical

ICS 11.040.10

In accordance with the provisions of Council Resolution 15/1993 this document is circulated

in the English language only.

Conformément aux dispositions de la Résolution du Conseil 15/1993, ce document est

distribué en version anglaise seulement.

To expedite distribution, this document is circulated as received from the committee

secretariat. ISO Central Secretariat work of editing and text composition will be undertaken at

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Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du

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Secrétariat central de l'ISO au stade de publication.

THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE REFERRED TO

AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.

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INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO WHICH

REFERENCE MAY BE MADE IN NATIONAL REGULATIONS.
© International Organization for Standardization, 2001
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ISO/DIS 10524-4
Copyright notice

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ISO/DIS 10524-4
Contents

Foreword.....................................................................................................................................................................iv

Introduction .................................................................................................................................................................v

1 Scope ........................................................................................................................................................................1

2 Normative references ..............................................................................................................................................1

3 Terms and definitions..............................................................................................................................................2

4 Symbols (and abbreviated terms) ..........................................................................................................................3

5 General requirements…….......................................................................................................................................4

6 Test methods............................................................................................................................................................6

7 Marking and packaging.........................................................................................................................................10

8 Information to be supplied by the manufacturer................................................................................................10

Annex A (informative) Example of pressure regulator ..........................................................................................13

Annex B (informative) Rationale ..............................................................................................................................14

Bibliography ..............................................................................................................................................................15

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ISO/DIS 10524-4
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 3.

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 part of ISO 10524 may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 10524-4 was prepared by Technical Committee ISO/TC 121, Anaesthetic and respiratory equipment,

subcommittee SC 6, Medical gas systems.

ISO 10524 consists of the following parts, under the general title Pressure regulators for use with medical gases:

 Part 1: Pressure regulators and pressure regulators with flow-metering devices for medical gas systems

 Part 2: Manifold and line pressure regulators
 Part 3: Pressure regulators integrated with cylinder valves

 Part 4: Low-pressure regulators intended for incorporation into medical equipment

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ISO/DIS 10524-4
Introduction

Pressure regulators are fitted within medical equipment to maintain a constant outlet pressure irrespective of

variation of inlet pressure or flow.

To enable correct application of these devices it is important that the operating characteristics are specified and

tested in a defined manner.

As pressure regulators of this type are often derived from products designed for industrial applications, this part of

ISO 10524pays particular attention to:
- suitability of materials;
- safety (mechanical strength and resistance to ignition);
- cleanliness;
- testing;
- identification;
- information supplied.

It is also essential that regular inspection and maintenance procedures are recommended.

Annex B contains rationale statements for some of the requirements of this part of ISO 10524. It is included to

provide additional insight into the reasoning that led to the requirements and recommendations that have been

incorporated in this part of ISO 10524. The clauses and subclauses marked with R after their number have

corresponding rationale contained in Annex B.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 10524-4
Pressure regulators for use with medical gases - Part 4 : Low-
pressure regulators intended for incorporation into medical
equipment
1 Scope

1.1 This part of this ISO 10524 applies to low-pressure regulators suitable for inlet pressures between 280 kPa and

600 kPa, supplied and packaged as for use in medical equipment intended for the administration of medical gases

in the treatment, management, diagnostic evaluation and care of patients for use with the following medical gases:

- oxygen;
- nitrous oxide;
- air for breathing;
- helium;
- carbon dioxide;
- xenon;
- specified mixtures of the gases listed above.

1.2 This part of ISO 10524 does not apply to pressure regulators supplied as spare parts for a specific application.

1.3 This part of ISO 10524 does not apply to pressure regulators for use with suction services (see ISO 10079-3).

2 Normative references

The following normative documents contain provisions which, through reference in this text, constitute provisions of

this part of ISO 10524. For dated references, subsequent amendments to, or revisions of, any of these publications

do not apply. However, parties to agreements based on this part of ISO 10524 are encouraged to investigate the

possibility of applying the most recent editions of the normative documents indicated below. For undated

references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain

registers of currently valid International Standards.

ISO 9170-1, Terminal units for medical gas pipeline systems - Part 1: Terminal units for use with compressed

medical gases and vacuum.

prEN 737-6, Medical gas pipeline systems - Part 6: Dimensions of probes for terminal units for compressed medical

gases and vacuum.
ISO 5359, Low-pressure hose assemblies for use with medical gases.

ISO 14971, Medical devices – - Application of risk management to medical devices.

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ISO/DIS 10524-4
3 Terms and definitions

For the purposes of this part of ISO 10524, the following terms and definitions apply.

3.1
adjustable pressure regulator

regulator which has been provided with a means of operator adjustment of the delivery pressure under normal use

3.2
bleed flow

intended small flow of gas to the atmosphere for the purpose of the correct operation of the regulator

3.3
closure pressure, P

stabilized outlet pressure, one minute after cessation of the flow, from a regulator where the flow has been set to

standard discharge
3.4
flow characteristic

variation of the outlet pressure in relation to the rate of flow from zero to maximum capacity flow of the regulator

with the inlet pressure remaining constant
3.5
hysteresis

lagging of the outlet pressure (effect) when the flow (cause) is varied so that at a constant inlet pressure the values

of outlet pressure measured with increasing flow do not coincide with the values of outlet pressure measured with

decreasing flow
3.6
low pressure
pressure of 1 400 kPa or less
3.7
maximum closure pressure, P
4 max

stabilized outlet pressure, one minute after cessation of the flow, from a regulator where the flow has been set to

maximum discharge
3.8
maximum discharge, Q
max

maximum flow which is delivered by the regulator at the rated outlet pressure, P at test inlet pressure, P

2 3
3.9
preset pressure regulator

regulator which has not been provided with a means of operator adjustment of the delivery pressure under normal

use
3.10
pressure characteristic

variation of the outlet pressure with inlet pressure under constant flow conditions

3.11
pressure regulator

device for regulation of a generally variable inlet pressure to as constant as possible an outlet pressure

3.12
rated inlet pressure, P
rated maximum upstream pressure for which the pressure regulator is designed
3.13
rated outlet pressure, P

rated downstream pressure for the standard discharge Q specified in the instructions for use

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ISO/DIS 10524-4
3.14
single fault condition

condition in which a single means for protection against a safety hazard in equipment is defective or a single

external abnormal condition is present
3.15
single stage pressure regulator

regulator that reduces the inlet pressure in a single stage to the required pressure

3.16
standard discharge, Q

flow, specified in the instructions for use for which the regulator is designed to maintain a rated outlet pressure, P

at test inlet pressure P
3.17
test inlet pressure, P

minimum inlet pressure at which the standard discharge of the regulator Q is measured and which is equivalent to

twice the rated outlet pressure P plus 100 kPa, i.e. P = (2 P + 100) kPa
2 3 2
3.18
two-stage pressure regulator
regulator that reduces the inlet pressure in two stages to the required pressure
4 Symbols (and abbreviated terms)
The symbols used for the physical characteristics are given in Table 1.

A diagram of typical pressure regulators with examples of terminology is given in Figure A.1.

Table 1 - Notations, symbols and designations
P Rated inlet pressure
P Rated outlet pressure
P Test inlet pressure (2P + 100) kPa
3 2
P Closure pressure
P Maximum closure pressure
Q Standard discharge
Q Maximum discharge
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ISO/DIS 10524-4
5 General requirements
5.1 Safety

Pressure regulators shall, when stored, installed, operated in normal use and maintained according to the

recommendations of the manufacturer, cause no safety hazard which could be foreseen using risk analysis

procedures in accordance with ISO 14971-1 and which is connected with their intended applications, in normal

condition and in single fault condition.
5.2 R Alternative construction

Pressure regulators and components or parts thereof, using materials or having forms of construction different from

those detailed in clause 5 of this part of ISO 10524 shall be accepted if it can be demonstrated that an equivalent

degree of safety is obtained.
Such evidence shall be provided by the manufacturer.
5.3 Materials

5.3.1 The materials in contact with the gas shall be compatible with oxygen, the other medical gases and their

mixtures in the temperature range specified in 5.3.2.

NOTE 1 Corrosion resistance includes resistance against moisture and surrounding materials.

NOTE 2 Compatibility with oxygen involves both combustibility and ease of ignition. Materials which burn in air will

burn violently in pure oxygen. Many materials which do not burn in air will do so in pure oxygen, particularly under

pressure. Similarly, materials which can be ignited in air require lower ignition energies for ignition in oxygen. Many

such materials can be ignited by friction at a valve seat.

NOTE 3 ISO 15001, Anaesthetic and respiratory equipment --- compatibility with oxygen is in preparation by ISO/TC

121/SC6.

5.3.2 The materials shall permit the pressure regulator and its components to meet the requirements of 5.4 in the

temperature range of 0 °C to +40 °C.

If the pressure regulator is suitable for use outside this temperature range, the range shall be specified by the

manufacturer.

5.3.3 Pressure regulators shall be capable, while packed for transport and storage, of being exposed to

environmental conditions as stated by the manufacturer.

5.3.4 Springs, highly strained components and parts liable to wear which come in contact with the medical gas shall

not be plated.
Note Plating could come off.

5.3.5 R Evidence of conformity with the requirements of 5.3.1, 5.3.2, 5.3.3 and 5.3.4 shall be provided by the

manufacturer.
5.4 Design requirements
5.4.1 Inlet pressure

5.4.1.1R Pressure regulators shall operate and meet the requirements of this part of ISO 10524 when supplied with

an inlet pressure ranging from 280 kPa to 600 kPa.
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ISO/DIS 10524-4

5.4.1.2 R Pressure regulators shall meet the requirements of 5.4.1.1 following exposure to an inlet pressure of

1 000 kPa for 10 min.
5.4.2 Inlet connection

If the inlet connection of the pressure regulator is intended to be used as the inlet connection to the equipment, it

shall be either a probe complying with prEN 737-6 or a NIST body complying with ISO 5359. Cylinder valve

connections shall not be used.
5.4.3 Outlet connection

If a gas-specific outlet connection of the pressure regulator is intended to be used as the outlet connection of the

equipment, it shall be either a socket complying with ISO 9170-1 or a NIST body complying with ISO 5359.

In this case it shall not be possible for the operator to set the outlet pressure below 280 kPa.

5.4.4 Pressure adjusting device

The 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 compressed to its solid length and thereby allowing gas to pass from the inlet

to the outlet side.
Compliance shall be tested by visual inspection.
5.4.5 Performance, functional and flow characteristics

The performance, functional and flow characteristics shall be in accordance with the values stated by the

manufacturer.
The tests are given in 6.2.
5.4.6 Over-pressure relief

If a means for over-pressure relief is provided, its characteristics shall be specified by the manufacturer.

The test is given in 6.3.
5.4.7 Leakage

The maximum external leakage (to the atmosphere) and internal leakage (through the regulator valve) shall not

exceed the values specified by the manufacturer.
The test for leakage is given in 6.4.
5.4.8 Bleed flow
The bleed flow shall not exceed the value specified by the manufacturer.
The test for bleed flow is given in 6.5.
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ISO/DIS 10524-4
5.4.9 Mechanical strength

The inlet and outlet sides of the pressure regulator shall be capable of withstanding 1 400 kPa without rupturing.

The test for mechanical strength is given in 6.6.
5.4.10 R Resistance to ignition

For pressure regulators for all gases the autoignition temperature of the non-metallic components in contact with

the gas, including the sealing materials and l
...