ISO 23551-2:2018

Safety and control devices for gas burners and gas-burning appliances — Particular requirements — Part 2: Pressure regulators

This document specifies safety, construction, performance and testing requirements for pressure regulators and pneumatic gas/air ratio pressure regulators intended for use with gas burners and gas-burning appliances. This document applies to pressure regulators and pneumatic gas/air ratio pressure regulators of nominal connection size up to and including DN 250 at inlet pressures up to and including 500 kPa, for use with natural gas, manufactured gas or liquefied petroleum gas (LPG). It is not applicable to corrosive and waste gases. This document is specifically applicable to: — positive, zero and negative pressure regulators which can use auxiliary energy to change the outlet pressure setting; — pneumatic gas/air ratio pressure regulators, which function by controlling a gas outlet pressure in response to an air signal pressure, air signal differential pressure, and/or to a combustion chamber pressure signal; — gas/air ratio pressure regulators, which function by controlling an air outlet pressure in response to a gas signal pressure or a gas signal differential pressure. This document does not cover: — pressure regulators connected directly to gas distribution network or to a container that maintains a standard distribution pressure; — pressure regulators intended to be installed in the open air and exposed to the environment; — mechanically linked gas/air ratio controls; — electronic pressure regulators and gas/air ratio regulators, which are contained in ISO 23552-1. This document covers type testing only. NOTE Annexes A to H reference the relevant annexes of ISO 23550, general requirements and are applicable where required.

Dispositifs de commande et de sécurité pour brûleurs à gaz et appareils à gaz — Exigences particulières — Partie 2: Régulateurs de pression

General Information

• Status: Published
• Publication Date: 19-Sep-2018
• ICS: 27.060.20 - Gas fuel burners
• Technical Committee: ISO/TC 161 - Controls and protective devices for gas and/or oil
• Drafting Committee: ISO/TC 161/WG 4 - Multifunctional Controls

Relations

• Revises: ISO 23551-2:2006 - Safety and control devices for gas burners and gas-burning appliances — Particular requirements — Part 2: Pressure regulators
• Effective Date: 10-May-2014

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 23551-2
Second edition
2018-09
Safety and control devices for gas
burners and gas-burning appliances —
Particular requirements —
Part 2:
Pressure regulators
Dispositifs de commande et de sécurité pour brûleurs à gaz et
appareils à gaz — Exigences particulières —
Partie 2: Régulateurs de pression
Reference number
©
ISO 2018
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
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below or ISO’s member body in the country of the requester.
ISO copyright office
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Published in Switzerland
ii © ISO 2018 – All rights reserved

Contents Page
Foreword .v
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
3.1 Pressure regulators . 2
3.2 Pressures . 2
3.3 Flow rates . 4
3.4 Component parts . 4
3.5 Performance . 5
4 Classification . 6
4.1 Classes of control . 6
4.2 Groups of controls . 6
4.3 Types of DC supplied controls . 6
5 Test conditions . 7
6 Construction . 7
6.1 General . 7
6.2 Construction requirements . 7
6.2.1 Appearance . 7
6.2.2 Holes . 7
6.2.3 Breather holes . 7
6.2.4 Vent limiters . 7
6.2.5 Screwed fastenings . 7
6.2.6 Moving parts . 7
6.2.7 Sealing caps . 7
6.2.8 Disassembling and assembling for servicing and/or adjustment . 7
6.2.9 Auxiliary channels and orifices . 7
6.2.10 Pre-setting device . 7
6.2.11 Adjustments . 8
6.2.12 Resistance to pressure . 8
6.2.13 Blockage of canals and orifices . 8
6.2.14 Signal tube connections . 8
6.3 Materials . 8
6.3.1 General material requirements . 8
6.3.2 Housing . 8
6.3.3 Springs providing closing force and sealing force . 9
6.3.4 Resistance to corrosion and surface protection . 9
6.3.5 Impregnation . 9
6.3.6 Seals for glands for moving parts . 9
6.3.7 Jointing . 9
6.4 Connections . 9
6.4.1 General. 9
6.4.2 Connection sizes . 9
6.4.3 Connection types . 9
6.4.4 Threads . 9
6.4.5 Union joints . 9
6.4.6 Flanges . 9
6.4.7 Compression fittings . . . 9
6.4.8 Flare connections . 9
6.4.9 Nipples for pressure test . 9
6.4.10 Strainers .10
6.4.11 Gas connections by GQC .10
6.5 Gas controls employing electrical components in the gas way .10
7 Performance .10
7.1 General .10
7.2 Leak-tightness.10
7.2.1 General.10
7.2.2 Requirements .10
7.2.3 Test .10
7.3 Torsion and bending .11
7.4 Rated flow rate .11
7.4.1 General.11
7.4.2 Requirements .11
7.4.3 Test .11
7.5 Durability .11
7.6 Functional requirements .11
7.7 Endurance .11
7.8 Vibration test .12
7.9 Putting the regulator out of action.12
7.9.1 Requirement .12
7.9.2 Test putting the regulator out of action .
...