RE: Hydro Test Pressure

many thanks again to everett. glad to have input from a certified API inspector (510 or 653?). good thing about the inner and outer ring for spiral wound gasket. our old spec requires only the use of centering ring manufactured to API 601 which was subsequently replace by ASME B16.5. about 4 or 5 years ago we keep experiencing failure of the winding in our product discharge system (polymer unit where the extruder is located). we deep sixed the old sp.wd and chnage the description of all our spare gasket to what you have said. by the way, have you use some of the low stress gasket that flexitallic was marketing a few years back? we've got a lot on our class 150 # piping. So far. no leak in our plant. Have you specified it before?

Everett, any guideline you may suggest for hot bolting - for flanges i n high temp application. a big partof getting a leak free joint is to ensure that the proper torque and sequence is followed. hell, forget about the torque - rpobably use the impact tools anyway to get the job done. for crtical application, this can not be ignored ( and opt for stud tensioning).

-----Original Message-----
From: EVERETT W. NICHOLS [mailto:enichols@bbtel.com] Sent: 29 May, 2001 10:16 PM
To: <a href="/group/PipingDesign/post?postID=8jHhNhawiUbIven49sfK1wT2Ef9SdGtC0ibBOdIFCawCXz2yBV-RgIFynFdLXi82ngVCZkVWc7eLoVSTrrGhXqXDLxLw">PipingDesign@yahoogroups.com</a> Subject: Re: [PipingDesign] Hydro Test Pressure

Ralph, Over the years I have use/specified many spiral wound gaskets, always Flexitallic. The optimum finish for these types of gaskets are 125-250 roughness average. My Flexitallic design criteria bulletin specifically states that range. When I talked to a representative several years ago (who we had for a seminar) he told me that 125 RA was his suggested recommendation. That is what I have always specified. Another suggestion when using spiral wound gaskets is to always spec a "outer" centering ring and a "inner" containment ring. This is Flexitallics CGI type. When I have done pipe inspections (I am a certified API Inspector) I have seen many spiral wound gaskets that had came apart with part of the spiral into the flow stream of the piping. The "inner" solid ring prevents this from occuring. Everett Received on Wed May 30 06:01:00 2001