Valve Fire-Test Standards: API 607, API 6FA, and ISO 10497 Comparison and Compliance
Updated: Aug 24
API 607, API 6FA, and ISO 10497 are separate valve fire type-test standards used for different product scopes and project requirements. A compliant test evaluates pressure containment, external leakage, through-seat leakage where applicable, and post-fire operability under the named edition. Buyers should specify the exact standard, edition, valve size and rating qualification range, and required test report rather than accept a generic “fire-safe” claim.
What Does API 607 Cover?
API 607 is the most widely specified fire-test standard for soft-seated quarter-turn valves and other valves with non-metallic seating components. The test subjects the valve to a controlled hydrocarbon fire maintaining a minimum average flame temperature of 760 degrees Celsius (1,400 degrees Fahrenheit) for 30 minutes. The valve is in the closed position under pressure during the fire exposure.
During the burn period, the test measures external leakage through the valve body and bonnet seals. After the fire is extinguished and the valve cools, a seat leak test measures through-seat leakage at reduced pressure. The acceptance criteria limit both external leakage and seat leakage to specified maximum rates. API 607 also requires the valve to remain operable after the fire test, verifying that the stem and actuator mechanism are not seized or damaged by thermal exposure.
What Does API 6FA Cover?
API 6FA is a separate API standard for fire testing valves used in petroleum-industry applications. Its applicability must be tied to the product specification, valve design, and purchase order. API 6FA should not be treated as an automatic substitute for API 607 solely because both standards evaluate valve performance during and after fire exposure.
The applicable API 6FA edition defines the exposure, pressure, leakage measurement, cooldown, and operability requirements for the qualified valve. The purchaser should verify that the submitted test report identifies the tested design, size, pressure rating, materials, sealing system, and permitted qualification range.
What Does ISO 10497:2022 Cover?
ISO 10497:2022 specifies fire type-testing for soft- and metal-seated isolation valves with one or more obturators. It evaluates through-seat leakage, external leakage, cavity overpressure relief for double-seated valves, and operability, and it defines rules for extending qualification to untested sizes, pressure ratings, and materials of the same basic design. ISO 10497 and API 607 address overlapping objectives but remain separate standards.
The selected edition defines the required fire exposure, cooldown, leakage measurements, and post-fire operation. Qualification should be evaluated from the complete test report, not only from a certificate title, because the purchaser must confirm the tested valve configuration and the permitted extension of qualification.
How Does a Fire-Safe Valve Maintain Integrity?
Fire-safe valve design incorporates features that maintain pressure integrity during and after fire exposure. The primary design feature is a secondary metal-to-metal seat that engages when the soft seat is destroyed by fire. In ball valves, this is achieved by designing the ball and body with metal seating surfaces that make contact when the soft seat insert is consumed. In butterfly valves, a metal backup seat provides sealing after the elastomeric liner burns away.
Stem packing is another critical element. Standard PTFE packing degrades at temperatures above 260 degrees Celsius. Fire-safe valves incorporate graphite packing or graphite packing sets with PTFE components positioned below the graphite so that the graphite provides sealing after the PTFE is consumed. Body-to-bonnet gaskets use spiral-wound gaskets with graphite filler or kammprofile gaskets with graphite facing that maintain sealing at fire temperatures.
How Should Fire-Test Compliance Be Specified?
When specifying fire-tested valves, reference the applicable standard and edition. For process plant valves, API 607 is the standard reference. For wellhead and drilling valves, API 6FA applies. For international projects, ISO 10497 may be specified. The specification should state that the valve must be fire-tested per the named standard and that a fire-test certificate must be provided. The certificate documents the test conditions, valve size and type, and test results.
Fire-test certification is type-based, meaning that one valve of a given type and size range is tested to represent all valves of that design. The certification covers a size range (for example, 2-inch through 12-inch) and pressure class. When selecting a fire-tested valve, verify that the specific size and pressure class fall within the certified range. Some manufacturers may have certification for certain sizes but not others within their product line.
Frequently Asked Questions
Are API 607 and ISO 10497 interchangeable?
Not automatically. The standards address similar fire-test objectives but have separate scopes, editions, procedures, and qualification rules. Acceptance depends on the project specification, purchaser requirements, local regulations, and the exact test report supplied for the valve design.
Does every hydrocarbon-service valve require fire testing?
Not necessarily. Fire-tested valves are commonly specified where a fire hazard analysis, code, owner standard, or project specification identifies loss of containment during fire exposure as a credible risk. The requirement should be documented for each valve service rather than assumed from fluid type alone.
Can metal-seated valves be fire-tested?
Yes. ISO 10497:2022 explicitly covers both soft- and metal-seated isolation valves, while the selected API standard must be checked for the product scope. For metal-seated designs, the test still evaluates pressure containment, external leakage, applicable through-seat leakage, and post-fire operability.
Do fire-test certificates expire?
The standards do not establish one universal calendar expiration for every certificate. Continued applicability depends on whether the current valve remains within the qualified design, size, rating, material, and sealing-system range and whether the purchaser accepts the test edition. Design changes that can affect fire performance require a formal qualification review and may require retesting.
Official References
Ted Wang
Wechat/Whatsapp: +86 18267833722
Email: sales@wofervalve.com
Website: www.wofervalve.com
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