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).

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