Technical requirements of the API 6FC standard: fire testing of check valves
This standard regulates test protocols and evaluation methods for the functional integrity of automatic check valves designed in accordance with API 6A and API 6D specifications under high-temperature (fire) conditions. Specialists at EV Group China emphasize that these requirements are aimed at unifying acceptance criteria for shut-off valves, regardless of the size or nominal pressure class of the product.
The document clearly defines permissible leakage rates: both through the internal closure member (check valve) and along the external seal circuit. Assessment is conducted in two stages: before and after maintenance work on the stuffing box assembly during the 30-minute period following thermal exposure.
The selection of the test time interval (30 minutes of direct burning) is based on analytical data confirming that this period is sufficient to extinguish most emergency fires at oil and gas infrastructure facilities. EV Group China engineers note that fires with longer durations are characterized by critical loads that exceed standard safety scenarios for this class of valves.