Sprial Wound Gasket vs Sheet Gasket

[Weko]

I'm trying to make several Piping Material Class (PMC).

Is there a rule when do we select to use spiral wound gasket or sheet gasket in a PMC?

 

[ione]

They could be made of SS 316 or SS 316L or SS 304 as metal component and graphite or PTFE as filler, depending on temperature and pressure service and fluid to be handled.

For further info you can check the links below

http://www.lamonsgasket.com/Gasket_Handbook.pdf

http://www.wermac.org/others/dim_gaskets_sw.html#top_of_page

 

[JJJ2000]

The folks at flexitallic claim that spiral-wound gaskets are better in a thermally cycling service than sheet gaskets. Given the trouble with cold flow that PTFE has this could be reasonable. I have been replacing my PTFE gaskets with spiral-wounds in thermal cycling service for about three years with good results so far.

 

[rgvrider]

I believe from memory, that sheet gasket is not recommend about about 2 MPa.

Sheet gasket is relatively cheep and useful in relatively 'easy' applications (ie low temp, low pressure, 'safe' fluids, etc).

 

[rmw]

Have a read in ASME B31.1, table 12 for where to use each respectively.

rmw

 

[unclesyd]

IAside from the temperature and pressure consideration you have to pick the filler, Teflon, carbon, mica, etc. This very critical in some application high temperature oxidizing fluids carbon is a no no. If the flange is marginal then try to go with carbon.
Watch out on 3" and 8" Class 150 SS flanges.
Picking the right gasket is about 2/3's of have a satisfactory joing the other is monitoring their use in the field,

Addenda:
We have a system where we have a highly oxidizing 1200°F, NOX, gas at 250 Psig and we spec. spiral wound gaskets, mica filled. I happened to hear a conversation about slugging down a 24" Class. 600 flange. Further inquiry led to fact that the gasket started leaking the second day after startup and had steadily gotten worse. I convinced them that the unit had to come down as something was bad wrong. When the flange was broken there was nothing but spirals no filler. 6 other flanges were examined and all had the wrong gasket, all had graphite filler. All but one was holding with nothing but the spirals. These gaskets have the inner ring.

 

[Weko]

thank you all.

ASME B31.1, table 112 is quite informative

now I got some reference where to start reading about gasket.