FLEXITALLIC GASKET (Gasket Factor (m) and MDSS (y)

[hplogger]

I wanted to know Gasket Factor (m) and minimum design seating stress of flexitallic gasket. I've checked Table 2-5.1 of ASME Code, but I do not know which of the gasket materials listed is the same with flexitallic gasket. Please advise! Thank you in advance.

 

[JLu]

Use the values for Spiral wound metal, asbestos filled, stainless/monel/nickel-base alloy (m=3, Y=10000psi/69MPa).

These values apply also for non-asbestos filler material like graphite, etc.

 

[gr2vessels]

hplogger,
Just a quick note of caution,Jlu has assumed the pretty obvious, that your gasket is a spiral wound;- however, you have not described the look of the gasket and the above assumption could be incorrect, hence the m and Y may also be incorrect. For your (and our) peace of mind, try to confirm the type of the gasket you mentioned or at least describe it to us, just to be on the safe side.
cheers, gr2vessels

 

[JohnBreen]

This might interest you:

http://www.garlock.net/product_techdata/M&Y Values 9-07.pdf

 

[hplogger]

The gasket is a flexitallic (spiral wound as confirmed)gasket, 3mm thk. x 470 O/D x 406 I/D to be fitted to 16" NB WNRF x 600# (Sch. 80) / 16" NB BLRF x 600#. Pls. advise. Thank you in advance.

 

[JLu]

gr2vessel was right, my assumption that it would be a spiralwound was made a little too quick. But as hplogger now confirmed it is indeed a spiralwound, you can use the values earlier mentioned (m=3/Y=69) in my opinion.

 

[condesinc]

Hplogger:

JLu is correct in the standard value for ASME Flange calcs for this product. You do not give the service, but since you are using moderate size std flange at not too high of # rating, this should be ok.

FYI, be aware that you can actually specify Y to a manufacturer...it depends on how tightly wrapped the chevron stack is (and I guess also on how tightly wrapped the designer is!

If you want to be doubly certain, I would call Flexitallic to verify.

We have some special service gaskets that are two separate inner and outer bands of SS-Graphite stack with nitrogen purge in the center. We specifiy two different Y's...softer for the inner than the outer.

 

[JohnBreen]

Hplogger,

condesinc said:
"If you want to be doubly certain, I would call Flexitallic to verify."

That was EXACTLY my point. From looking at the cited Garlock page you can see an example of the amount of information that should be normally available to the end users - the OEM wants you to buy the product and should be willing to give you all the design data that you need. That should be your "first stop".

Regards, John

 

[hplogger]

Thank you guys for all your valuable posts. It helped me a lot.