Emergency Shutdown Valve 2

Their need is developed as a result of your Hazop's for your process. The basic objective is to stop the reaction and purge or quench the process. In some cases they are used to reduce the cycling of the emergency relief system.

To my knowlegde NFPA and the nuclear codes cover manditory emergency valving for reactive processes, but that has been my own experience.

I prefer the term automated valve unless otherwise required. Be careful of the usage of the terms "emergency shutdown" and "emergency shutdown valve". Requirements vary by industry and application.

For the offshore industry, the US Department of Interior Minerals Management Service requires compliance with API RS 14C. Among requirements, the shutdown valve must close within 45 seconds.

ISA 84 pertains to Safety Instrumented Systems. This addresses the safety integrity level for each process system or application node. 29CFR1910.119 applies to hazardous processes.

BTW, HAZOP is one technique of process hazard analysis. However, the hazard analysis should identify areas requiring elevated safety integrity levels.

Think bubble tight and fire-safe. Perhaps the quarter turn valves compliant with the line specification are suitable for use as an automated "shutdown" valve. Some clients require partial closure testing for testing automated valves when used to shutdown a process. High temperatures and metal seats can be an issue.

Burner management systems, nuclear plants etc. likely have different requirements. Consider refering to the plant insurance requirements but you are unlikely to ever find what they are until the place blows up.

If you are working on a project for another company, determine the codes and standards applicable to the project and assure compliance.

John

JSAkins,
The valve component pressure design requirements would be in standards like ASME B16.34 ,API 600, API 6D, etc.
The emergency shutdown valve system requirements would include the actuators, fusible links, stop swithches, lanyards, instrumentation and control interlocks.
There are differing requirements for different industries and jurisdictions, as mentioned by hacksaw and jsummerfield. The LPG distribution industry has NFPA 58 for requirements at railcar unloading / bobtail truck loading docks. Examples of the emergency shutoff valves with actuators and manual lanyard release mechanisms can be viewed at the LP equipment catalogs of the LPG division of Fisher Controls-McKinney, and at Rego-ECII.
There was a project with railcar unloading of HCN, acrolein, and methyl mercaptan. Each unloading arm/hose was fitted with an pneumataic actuated fire-safe butterfly valve (or Fisher N580 valve) at dock end and at tank car dome, that could be actuated at the valve or remotely, in event of a leak of unloading arm or hose failure. (That was before the heightened concerns following the Bhopal chemical leak disaster.) Another example of an emergency shutdown valve is the blow out preventer BOP at oil well head. So check for the best practice around the industry, and the insurance carriers if a jurisdiction is also involved (in states requiring Code Boilers).