Recommendations for Relief Valves on Gas Carriers 3rd Edition (eBook)

Look Inside

Published Date

February 2020

Also available in other formats:

Recommendations for Relief Valves on Gas Carriers 3rd Edition (eBook)

(Excludes any applicable taxes)

Relief valves perform a safety critical function. Proper design and robust maintenance procedures are essential to ensure that this equipment will function as required. The purpose of this document is to provide information to support this goal.

This publication is the third edition of SIGTTO’s guidance on relief valves and it updates the previous edition An Introduction to the Design and Maintenance of Cargo System Pressure Relief Valves on Board Gas Carriers, 1998.

Be the first to review this product

These recommendations are for liquefied petroleum gas (LPG) carriers and liquefied natural gas (LNG)

carriers. For the purposes of this document, the term LPG refers to liquefied gas cargoes carried between the

temperature range of 0°C to -104°C.

These recommendations do not apply to existing ships, and there is no suggestion that existing ships should be


It is recognised that some gas carrier designs may not be able to conform to all of the recommendations in this

document. However, this document is intended to serve as a starting point with a view to minimising differences

as much as possible.

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


Annex 1 – Auxiliary Setter Installation Procedure

Annex 2 – Metal to Metal Valve Seats

Annex 3 – Glossary of Terms and Abbreviations

Annex 4 – Reference List

The purpose of SIGTTO is to promote shipping and terminal operations for liquefied gases which are safe, environmentally responsible and reliable. To fulfil this mission it will:

  • Proactively develop best operating practices and guideline

  • Sustain a learning environment by sharing lessons learned

  • Promote training and development of all within the industry

  • Foster mutually beneficial relationships with regulatory authorities and other stakeholders

  • Conduct its business with professionalism and integrity

Title: Recommendations for Relief Valves on Gas Carriers 3rd Edition (eBook)
Number of Pages: 52
Product Code: WS1734EA
ISBN: ISBN 13: 978-1-85609-826-7 (9781856098267), ISBN 10: 1-85609-826-5 (1856098265)
Published Date: February 2020
Binding Format: Paperback

Bought this product? Why not review it?

If you have a question about this product, please contact us directly.

Windows eBooks:


To access the eBook, you need to install our free Windows eBook Reader.

The application can be downloaded from:


Standalone eBooks are supplied with 1 licence + 1 backup and are not transferable between platforms.


Remote Desktop Services (Terminal Services) and virtual environments are not supported.


The Windows eBook Reader works with Windows XP or later OS (but not Windows RT).

See more details.


Cloud (online) eBooks:


The Cloud (online) eBooks use Microsoft Silverlight browser plugin to deliver the best possible reading experience with the ability to work in offline mode.


It is an annual subscription service (i.e. each eBook is purchased for 1 year of use).

Online licences are not transferrable to Windows or iPad (or vice-versa).


Silverlight is compatible with the major web browsers used on Windows and Mac OS X operating systems.

However it is not supported on Linux, Android, Windows RT and iPad devices and therefore the Cloud eBooks use an HTML site in these instances.

The HTML site is more restricted than the Silverlight version.


See and more details.


Note for Mac Users:


Mac users can read Windows eBooks with Boot Camp or using virtual machines such as Parallels Desktop, Virtual Box, ...

Alternatively, Cloud (online) eBooks are accessible on Mac, including the Silverlight plugin with offline mode.


Note for Linux Users:


Linux users can read Windows eBooks using a virtual PC.

Alternatively, the HTML version of the Cloud (online) eBooks is accessible.


Note for Tablet Users:


Tablets owners can use the HTML version of the Cloud (online) eBooks.


Look Inside Text