API 641 Standard

ISO 15848-1 (Part 1): Classification system and qualification procedures for type testing of valves.
ISO 15848-2 (Part 2): Production acceptance test of valves.

Evaluates low emissions performance of quarter turn valves over an accelerated life cycle

API 641 was first released in 2016 and focuses solely on ¼-turn valves

This standard is meant to mimic real-world conditions through multiple thermal and mechanical cycles.

API 641 was released after API 624 which only addresses type testing for multi-turn valves.
Using methane as the test medium, API 641 uses the sniffing method outlined in Method 21 to determine leakage in PPMV.
Strictly a pass/fail test with no adjustments allowed.
Must remain below 100PPM.

Specifies the requirements and acceptance criteria for fugitive emission type testing of quarter-turn valves, issued by the API organization.

Type testing requirements contained are based on elements of EPA Method 21.

Test to the max temperature and pressure rating of the valve.

Design tested to API 641

Valve Class is based off temperature ratings