Service Selection

Gate Valves for Ammonia (NH₃) Service

Which gate valves configuration suits Ammonia (NH₃) (NH₃), in which material, to which standard — from real service data, with the pitfalls flagged.

Which gate valves for Ammonia (NH₃)?

Cryogenic gate valve (extended bonnet) - Liquid ammonia -33°C storage - extended bonnet keeps packing at ambient Typical service window: Up to 25 bar (refrigerant); up to 200 bar (synthesis gas), -33°C (liquid refrigerant) to 300°C (synthesis service).

Recommended Configurations

Cryogenic gate valve (extended bonnet)

Liquid ammonia -33°C storage - extended bonnet keeps packing at ambient

Body Material for Ammonia (NH₃)

Rated from real compatibility data - click any material for the full decision page.

Carbon SteelStandard for ammonia - both refrigerant and process service.Excellent SS 304Acceptable but not normally required. Used where contamination is a concern.Good PTFEAcceptable for seats and seals.Good EPDMAcceptable for refrigerant ammonia seals.Good Bronze/BrassSCC and corrosion - strictly prohibited in ammonia service.Not Recommended Zinc alloys / Die-cast zincAttacked by ammonia - all zinc must be absent.Not Recommended NylonDegraded by ammonia.Not Recommended

Governing Standards for Ammonia (NH₃) Service

IIAR 2 - Ammonia refrigeration piping and equipmentASME B31.5 - Refrigeration pipingASME B31.3 - Process piping (process ammonia)ISO 15848 (fugitive emissions for toxic service)

What to Avoid in Ammonia (NH₃) Service

Any valve with copper, brass, or bronze wetted parts or body
Valves with zinc die-cast components
Nylon or polyamide-seated valves

Service Considerations

No copper or zinc - inspect every valve for copper alloy trim before installation
Extended bonnet design for cryogenic (-33°C) liquid service
Emergency isolation must be remotely operable
Refrigerant grade NH₃ is oil-free - valves must be clean and degreased