Maximum raised face on a flange 1

[TechThrm]

Either the standard raised face flanges are 1/16" or 1/8" raised face. But is there some standard set by ASME on the maximum raise face a flange can have?
I am designing a flange per Section VIII Appendix 2.

Thanks

 

[pennpiper]

Check:
ASME B16.5 and ASME B16.47

 

[racookpe1978]

Well, technically, the "standard" flanges aren't intended to restrict "your" design of "your" flange at all.

After all, "I" don't care what size and shape "your" flange wants to be, nor can I control how "your" flange is designed nor what service "your" flange will see. (And, since I don't know what your requirements are, I can't - and shouldn't - limit your needs. 8<)

But ... the standards aren't set up for YOUR desires (heck, they aren't set up for MY desires either!), they are set up so I can buy uniform, affordable flanges from any fabricator that will fit any other fabricator's flanges and fittings regardless of when the eqpt was built and who built the mating fitting, flange, or valve.

The standard sizes are made so the fabricators can produce flanges and fittings without fighting thousands of different sizes and spec's every time they get an order. At your end, if you need some odd configuration that needs to be specialty-cast, shipped to a forge shop, forged and thrown on a machine shop's lathe and specialty-turned for an hour or so to get what you need.... Then you need to decide how much extra time and extra cost that special design will involve.

If you can use standard sizes, then you can call up a standard supplier and get a standard size at a standard cost on a standard pallet on the back of a standard truck. Tomorrow afternoon. 8<)

 

[TechThrm]

I am sorry racookpe1978, I guess you got me wrong. what I wanted to know is if there is any code limit on maximum raised face a flange can have.
B16.5 gives standard raised face dimensions, (1/16" for less than or equal to class 300 and 1/4" for anything more than class 400) "unless otherwise ordered" but no where it talks about the maximum raised face a flange can have.

 

[SnTMan]

TechThrm, as far as I know, there are no limits in Sec. VIII, Div.1 on raised faces.

A 1/16" R.F or groove can be considered as included in the calculated thickness, anything in excess must be added, so that can be a kind of practical limit.

3/16" and 1/4" are fairly common, but others can be used as well.

Regards,

Mike

 

[racookpe1978]

No. No limit on height of the RF at all, but remember "you" are the one who has to pay for the specialty forging and machining costs for the flange.

On a practical basis, the bolts/studs you use on the flange have to have to create and maintain the grip between the two outside flange faces that clamp the gasket on both sides to prevent leakage. The gasket is going to be clamped only at the RF surface.

 

[SnTMan]

I should have added that the 1/16" provision applies to integral flanges only.

Mike