Forum: Reliability & Maintainability Questions and Answers
Posted by: Tom Wendling (firstname.lastname@example.org )
Date posted: Tue Jun 28 18:18:19 US/Eastern 2005
Subject: Reliability Data for Liquid Process Equipment
I am searching for reliability data (ie. hazard function parameters) for liquid process equipment (ie. pumps, valves, mixers, membranes, scraper mechanisms, tanks, heat exchangers, etc., and their subcomponents). I realize that reliability engineering has been driven mostly by the electronics industry, but would like to know if someone can point me in the best direction to find extensive data, preferably in electronic database format in this field. If you can offer any guidance, I would appreciate very much hearing from you at: email@example.com Thank You very much
Posted by: Geoff Hampden-Smith (firstname.lastname@example.org )
Date posted: Fri Jun 24 5:58:23 US/Eastern 2005
Subject: Component Confidence levels
The target availability for a 3 component parallel system (valve shutdown system) is 99.95%. The three components have similar failure rates. However, the failures of the components are only revealed on testing.
The question is what confidence limits should be chosen for the individual components to have a 95% chance of shutdown on demand for the parallel system. Any direction on performing the calculation would be appreciated.
Posted by: Geoffrey Hampden-Smith (email@example.com )
Date posted: Fri Jun 24 5:40:18 US/Eastern 2005
Subject: Component failure rate and availability of unrevealed failure data
We carry out valve testing at irregular periods ranging
from 12 to 364 days. (This arises as we take advantage of opportunities duringprocess shut downs). A series of successful tests (valve passes)takes place, and then the valve is found to have failed (once the failure is revealed it is repaired immediately in about 1 hour). Can the average availability calculated as: 1) [SUM TEST PERIODS (days) VALVE PASSED + 1/2*(SUM OF TEST PERIODS (days) IN WHICH VALVE FAILURES ARE REVEALED]/ [SUM TEST PERIODS VALVES PASSED (days) + TEST PERIODS (days) IN WHICH VALVES FAILED] (The Denominator equals the TOTAL TIME) 2) Is the valve failure rate calculated as: [NUMBER OF VALVE FAILURES]/[TOTAL of TEST PERIODS (days) VALVES PASSED + 1/2*(SUM OF TEST PERIODS (days) IN WHICH VALVE FAILURES ARE REVEALED)]
Posted by: Jean-Marie Claorec (firstname.lastname@example.org )
Date posted: Tue Jun 14 4:01:53 US/Eastern 2005
Subject: Impact of nonoperating periods on reliability
The report RADC-TR-85-91 was issued in 1985.
I'd like to know if this report was updated or superseded by another publication from RAC or others organism? Thanks
Posted by:Bradford Simpson (email@example.com )
Date posted: Sat Jun 11 13:48:52 US/Eastern 2005
Subject: Genrating/Tutorarial for Maintainability Demonstration Plans
This is my first time looking at or Trying to develope a Maintainability Demonstration Plan/Test and a Testability Demonstration Plan for an APU. Can someone pont to any work instructions or procedures on how to geyt started. I have generated reliability/maintainability/safety program plans. Please can you also e-mail infrmation to firstname.lastname@example.org