Maintenance procedures/frequencies final elements

[snafu51]

Are there any papers, textbooks etc, that deal with maintenance procedures/frequencies for SIS associated final elements?
Specifically - Valves.

 

[Guidoo]

There are quite a number of papers around on testing and determining required test frequencies for SIS related valves, e.g. on partial valve stroke tests. Do you really mean valve maintenance or do you mean valve proof test?

 

[snafu51]

I'm meant preventative/periodical maintenance functional testing. Thanks for the response.

 

[RobV]

Part of determining the correct choice of final elements, the IEC 61508/61511 required that realiability calculations be done. These calculations require the 'Probability of Failure on Demand' whihc is a function of the certified failure rate and the proof test interval.
Hence the frequency of the proof test is already determined by the choice of SIS system and the final elements.

The lifetime cycle can also be determined using similar approaches but is dependant of the proof test coverage factor.

I think that the IEC standard contain some good reading of the subject Safety Life Cycle. It incorporates a kind of QA based approach to the matter.
You could also read the DIN/DVGW G-495 standard whihc contains a section operation/maintenance including issue realting to maintenance and testing frequencies.

 

[snafu51]

Thanks Rob, I'm very familiar with IEC 61508/61511 and ISA S84. Quantitative Risk Assessment is the primary part of my job. I'm actually looking for a good source of testing procedure recommendations for valves. The "frequencies" portion of the posting should not have been there. I have a client looking for a source/s for recommended testing steps for valves. I've provided a paper on the subject of test procedures but the client is seeking another source. Thanks again.