BVAA: Hotspot - NWIP ISO 4126-11 Performance Testing of Safety Devices

What is it? 

ISO TC 185 have issued the attached new work item proposal relating to a new performance testing standard for safety valves as part of the ISO 4126 family of standards. BSI will vote on behalf of the UK as to whether this work item should be approved. The purpose of this Hot Spot is both to draw attention to the work item and also to invite any comments on the need and potential benefits, or otherwise, of this standard.

Please pass any comments that you may have to the BVAA secretariat before 16/4/21 so that we can forward them to the PSE 18/06 committee for consideration by BSI prior to voting. Please note that a favourable response with UK participation requires that the UK nominate an expert to participate in the ISO working group developing the standard. If you or your organisation have knowledge and experience of safety valve performance testing and would like to participate in the development of this standard please also contact the BVAA secretariat to express an interest.

The standard is intended to define the testing procedures to be applied for carrying out performance tests on closing, non-reclosing and combined safety devices for protection against excessive pressure as specified in ISO 4126 Parts 1, to 10, with particular reference to type testing.

Inlet and outlet conditions and back-pressure influence shall be considered, if necessary. Special consideration should be given to test rigs, its measurement techniques and precision as well as to testing procedures. Further topics to be considered must be low and high pressure applications.

Why is it Important? 

There are existing type test standards for safety valve performance such as ASME PTC 25 and  VdTUEV 100, but neither of these standards have the status of an international standard. Therefore, a vote to approve this work item should take into account the potential benefits and disadvantages of the existing standards and the implications of publishing a further standard on this subject, possibly including different test methods or requirements.

The standard will define test procedures to carry out type tests. Type tests are needed to fulfil the requirements according to the pressure equipment directive for certification of safety devices. The method and equipment used for such testing may affect the quality and accuracy of the test results. This standard would ensure performance tests are conducted and completed in a repeatable manner irrespective of testing location. Both, the requirements of manufacturers of safety devices and plant operators applying the devices must adequately be considered in a test procedure for the function and performance of the safety devices.

Continuous Improvement

Did we miss anything?

Hot Spots are intended to alert members and provide a brief overview of new standards, activities or procedures that are being introduced in the industry. If there is key information missing that would be helpful, please let us know so that we can improve our future service.

This Hotspot is for information purposes only. We invite comments from BVAA members only. Please also note that at time of publication ballots may be closed. For more information please contact the Secretariat: enquiry@bvaa.org.uk 

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