The key issue in answering this question is what edition of API 607 do you want to comply with, or compare to BS 6755 part 2 (Fire test)? Both standards cover test rig design, test procedure, acceptance criteria and qualification. BS6755 Pt 2 has been around since 1987 without any significant revision, API 607 Fourth edition was published in 1993, and prior to this it was the third edition. However there is a very significant difference between the two editions. API 607 Third editionwas almost identical to that of BS 6755 Part 2; consequent testing to either of the above would enable the valve to be certified to both BS and API.
However the significant single amendment, which separated the API standard from that of the BS, was the addition of a valve operation and leak test. The valve has to be operated in API 607 4th Ed from the closed to fully open position and then re-closed, the leak rate is then recorded.
In BS 6755 Pt 2 as in API 607 third edition the valve is fire tested for the pre-requisite + hour at 760-980 Av deg C, then the leakage recorded. The only operation to open the valve is made to record torque only after all leaks are recorded.
Therfore writing valve specifications with API 607 Fourth edition not only means that the valve will be fire-tested but it will be certified to the harder fire-test currently used in the industry.
Typically both valve specifiers and manufacturers specify æFire-tested to API 607Æ without reference to the edition; obviously this will lead to interpretation and should be clearly defined.
Test parameters and qualification criteria are similar in both standards; it is advisable that the individual review the detailed criteria from each standard.
Firetest API 6FA[/b an old standard,it has no simile with the current API607 standard.
BS6755 Pt1 (ambient pressure testing)has been made obsolete by BS EN 12266.However BS6755 Pt2 (fire testing)has been superceded by BS EN 10497 2004.
Both these standards are used for soft and metal seated products if they are deamed to be bubble tight by the manufacturer, although the standards typically only make reference to 'Soft seats'.
Author - B.Horsfield
