Have I got this gasket sizing correct for ASME B16.5 flange? 1

[ca2n]

Hello all,

First post here, so please be kind .

Long story short, I was tasked to (laser) cut a given gasket material to size to fit some flanges.

A particular flange was of the type B16.5 2-inch WNRF S40S 150lb.

I've sourced the gasket dimensions from the Piping World website.

Upon seeing the cut gasket and flange side-by-side, I'm having doubts as to whether or not the gasket dimensions I've sourced are indeed for the flange I have. In particular, it is the mating between the raised face of the flange and the gasket that is worrying me.

Have I prepared (cut) the correct gasket for this particular type of flange? Should have I sourced the gasket dimensions elsewhere?

Any advice appreciated.

 

[LittleInch]

No, you have cut a flange for a Full face (FF) flange.

What you have is a Raised Face (RF) flange. You have a WNRF - Weld Neck Raised Face Flange

You should source your dimensional details from ASME B 16.21 - Non metallic gaskets for ASME B 16.5 flanges

I'm going to cut you a bit of slack here as you can probably find this on line anyway, but here are the dimensions for a gasket for a 2" Class 150 flange.

You're only interested in the first two columns, not the Full face one.

Piping world call them flat ring gaskets to match what B16.21 call them...

https://www.piping-world.com/dimension-of-class-150-flat-ring-gaskets

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[ca2n]

Hello LittleInch,

Thank you ever so much for confirming my suspicions.

I only have myself to blame for not independently verifying what was actually needed, but there will be discussions about this at the office.

Now that I see what I need are ring gaskets, is there a particular technique to hold a gasket in place while tightening the flanges up? With full face gaskets, I suppose the flange bolts keep them in place while everything is done up, but for ring gaskets...?

Thanks again.

 

[LittleInch]

Basically it's the same only the flange fits almost exactly inside the bolts. OD of the gasket is 105, ID of the bolt holes with the studs in is about 108.

For vertical flange faces, the usual technique is to install the bottom two studs, then insert the gasket then the top two studs and tighten up.

Horizontal faces just lay the gasket on the RF portion and when the mating flange is positioned just drop the studs in one by one. If the gasket has moved just poke it with something to get it back in its correct location....

Oh and they are NOT "ring" gaskets. They are normally "rings" of solid metal in what are termed Ring type joints or RTJs.

You have a standard RF flange requiring what B16.21 calls FLAT ring gaskets. The "flat" bit is important....

I do have to ask:
a) why did someone not just but a gasket from a recognised gasket supplier?
b) why are you not using some form of compressed fibre / metal coated material
c) Is this material suitable for gasket service?
d) Do you not have a pipe fitter who can do all this for you?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[ca2n]

I'm loving all the detail you've provided!

As for your questions, believe me when I say I've asked them as well, and the answers I've come up with to convince myself are:

a) and d) it's a cost saving manipulating exercise. Rather than simply ordering them off the shelf, somebody seemed to have thought it would be "better" if somebody else (read: me) was given a list of supposed flanges to make gaskets for (none wherein "raised face" had been specified) and a sheet of material to cut them from. Had I not investigated myself what the flanges actually were, I would have already wasted hours getting them (50+) cut, not to mention the amount of material wasted. Which conveniently brings me to:

b) and c) material is "compressed", "inorganic fibre", "based on Aramid", whatever those mean. Suitability? As with the flange gaskets, it looks like I might need to do my own investigation on that.

"Frustrated" doesn't even begin to explain what I'm feeling at the moment with my organisation. But this is probably not the place for venting.

 

[MJCronin]

I believe that this thread serves as a stern warning for the future...

It is, IMHO, required reading for all of the participants of eng-tips !!!!!!!

I am beginning to stongly sense the presence of an MBA here .....

.... As evidenced by the assignment of "anybody" to "any job" for results expected "immediately"

_____________________________________________________________________________________________________

Ca2n, just buy your pipe gaskets from a longtime supplier like FLEXITALLIC ..... like everyone else does !!!

We suggest that you buy some books on Piping design, fabrication, assembly and testing ... read and understand them

Find a new boss....

MJCronin
Sr. Process Engineer

 

[Latexman]

MJCronin, you don't sound a bit bitter.

Good Luck,
Latexman

 

[LittleInch]

If you hang around long enough, you'll find MJC has a really deep hatred (no joking) of people with MBA's.....

Compressed fibre should be ok, but I doubt anyone is saving any money here,,,,

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[LittleInch]

If you get a RTJ type flange, i.e. normally class 600 or above with a groove in the flange please don't try to make a gasket for it. You really do need to buy those ring joints....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.