Recommendations for Relief Valves on Gas Carriers - 3rd Edition

Published: March 2020

Author: SIGTTO

This publication describes and illustrates the various types of relief valve and sets out general requirements with reference to the IGC Code. It provides recommendations on selection, design, operation and maintenance and advises on common operating problems and faults.

Contents Listing:

1 Introduction and Scope

2 Relief Valve Types

2.1 Pilot Operated Relief Valves

2.2 Spring Loaded Relief Valves

2.3 Comparison of Pilot Operated and Spring Loaded Relief Valves

2.4 Vacuum Operation of Pilot Operated Relief Valves

3 Relief Valve Requirements

3.1 General Requirements

3.2 Basic Design Requirements

3.3 Installation Design

3.4 Materials

4 Recommendations

4.1 Selection and Design

4.2 Operational

4.3 Maintenance

4.4 Maintenance and Care of Diaphragms

4.5 Routine Testing

4.6 Field Test Kit

5 Operating Problems and Faults

5.1 Operating Problems

5.2 Faults

5.3 Chloride Stress Corrosion Cracking

5.4 Emergency Closure of Relief Valves

Annexes

Annex 1 – Auxiliary Setter Installation Procedure

Annex 2 – Metal to Metal Valve Seats

Annex 3 – Glossary of Terms and Abbreviations

Annex 4 – Reference List