API fire testing for Metal Seated Ball valve

[breaker34]

We have our soft seated ball valves fire tested to API 607, which refers to fire testing for soft seated quarter turn valves. Is there a API standard for metal seated valves?

 

[vpl]

It's been a while since I looked at the API standards, but if memory serves me, most people just use the API 607. I think it's because the limiting component is usually not metal seat.

Patricia Lougheed

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[NGiLuzzu]

Fire testing standards have had a turbulent history in the last years...: in 2005, API issued the 5th edition of its standard n° 607 as identical to ISO 10497 of 2004, which was applicable to industrial valves in general, even if API title mantained the reference to "Soft-seated Quarter-turn" ones (!); the 2010 editions, instead, differ in a few lesser details, but officially stand as two separated standards again (and API title changed into "Fire Test for Quarter-turn Valves and Valves Equipped with Nonmetallic Seats"... simple, isn't?).

In my opinion, metal seated valves may be considered fire safe by design, provided that materials are properly selected, dimensions and tolerances correctly choosen and realized, etc... and the valve design itself is sufficiently proven-in-use.
But sometimes a test certificate is easier to obtain than Customers reasoning (about the above aspects); so, some Manufacturers applied the API "Soft-seated" procedure to metal seated valves too, perhaps complying with stricter acceptance criteria (no visible leakage before, during and after the fire, for example)...


Hope this helps, 'NGL
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[bcd]

When API 607 was revised and co-branded with ISO 10497, the reference to "soft seats" was removed from the title. The ISO version of API 607 can be used for metal seats. When the 6th edition of API 607 was released this year, it no longer is co-branded as an ISO standard and the term "soft seated" appears in the title again.

So for metal seated valves, you can state they are naturally fire safe provided they don't contain any parts or seals that will melt at the test temperature, or when you get tired of explaining to inexperienced customers why you don't need to fire test metal seated valves, just test to ISO 10497. It will be a long time before this standard ever gets revised.