scope:

Introduction and Scope

This document sets out guidance for the installation and operation of isolating valves which allow the removal of relief devices from operating plant. It draws on the experience and different practices of EEMUA members to identify the key points which should be considered in the design and management of such isolation systems.

The term 'isolation valve/device' may be interpreted to include spectacle blinds/ slip plates where these are used instead of valves for the isolation of relief devices.

The term 'relief/relieving device' normally refers to a safety/relief valve, bursting disc or other mechanical relieving device.

Important: None of the comments or recommendations made in this guide removes from the designer and/or user the responsibility of ensuring that the relief device installation is safe and that it complies with the applicable national and industry standards and regulatory requirements.

Note on terminology: The terms 'relief valve', 'safety valve' and 'safety relief valve' are widely used in industry and have specific meanings in US standards; however, only 'safety valve' is defined in ISO standards (see API RP 520 Part I and ISO 4126). No distinction is made between these terms in this guide.