[timstorey]

The CADWorx install data tables include the raised face in the overall flange dimensions. One has to add tables for flat face flanges. Weld neck flanges (as an example) are forged into a dimensional shape based on the required class/standard and then holes, welding bevel and facing are machined.

[timstorey]

Texas Flange has a page on their website showing alternate flange facings. Large male/female are neither FF or RF.

http://www.texasflange.com/Alternate%20 … cings.html

I have never seen these installed, hence the term “rare.”

[timstorey]

There are (2) types of male / female flange sets, one called large, one called small, based on area available for gaskets. This is rare, but may be what you looking for (I found it in my Grinnell flange catalog, WFF-81).

[timstorey]

SAE (Society of Automotive Engineers ) Flanges maybe.

[timstorey]

Depends on environment and service. Threading will work in some cases, not in others. SS threads tend to gall. We have added SS nozzles to CS vessels, choosing the correct welding rod is important.

[timstorey]

Sorry, no union dimensions.

[timstorey]

Sorry, no union dimensions.

[timstorey]

Bob,

Try a manufacturer’s website for dimensions.

Penn USA has Class 9000 dimensions.

Tim Storey

[timstorey]

Bob,

Try a manufacturer’s website for dimensions.

Penn USA has Class 9000 dimensions.

Tim Storey

[timstorey]

Thank you so much.
So a vessel nozzle and a flange with different rating I can connect , but can I connect, for example, a 150# flange with a 300# flange?
I’ve checked flange tables and I realized the outside diameter and number of bolts for a certain diameter are different. Then, I conclude we cannot connect them. Is that right?

Thank you again.

That is correct, a Class 150 flange will not match up with a Class 300. You need to match the tank nozzle with a Class 300 flange. It is usually allowable to go up in flange rating, but I would be curious on why the vessel has a rating requiring Class 300 and the connecting piping is only rated for Class 150.

[timstorey]

Thank you so much.
So a vessel nozzle and a flange with different rating I can connect , but can I connect, for example, a 150# flange with a 300# flange?
I’ve checked flange tables and I realized the outside diameter and number of bolts for a certain diameter are different. Then, I conclude we cannot connect them. Is that right?

Thank you again.

That is correct, a Class 150 flange will not match up with a Class 300. You need to match the tank nozzle with a Class 300 flange. It is usually allowable to go up in flange rating, but I would be curious on why the vessel has a rating requiring Class 300 and the connecting piping is only rated for Class 150.

[timstorey]

Acording to the piping class of a plant where I´ll have to perform a branch connection, a sockolet has has to mounted for 4″ x 12″ connection. As an alternative for tie-in, which means cutting and most important, closing the pipeline, i´m planning to perform a Hot Tap, wich doesn´t need a reinforcement. Do I have to weld the sockolet anyway?. The length of my hot tap machine may not be long enough to drill with the sockolet and the valve mounted.

Regards,

Zero

You should meet the plant standards, or have the piping engineer approve any variations from those standards. A 4″ sockolet is a very large sockolet, is post weld heat treating required? Why wouldn’t the hot tap have the same reinforcing requirements as the sockolet?

Sorry to ask so many questions, but more information is needed to get a good answer.

Tim Storey

[timstorey]

Acording to the piping class of a plant where I´ll have to perform a branch connection, a sockolet has has to mounted for 4″ x 12″ connection. As an alternative for tie-in, which means cutting and most important, closing the pipeline, i´m planning to perform a Hot Tap, wich doesn´t need a reinforcement. Do I have to weld the sockolet anyway?. The length of my hot tap machine may not be long enough to drill with the sockolet and the valve mounted.

Regards,

Zero

You should meet the plant standards, or have the piping engineer approve any variations from those standards. A 4″ sockolet is a very large sockolet, is post weld heat treating required? Why wouldn’t the hot tap have the same reinforcing requirements as the sockolet?

Sorry to ask so many questions, but more information is needed to get a good answer.

Tim Storey

[timstorey]

If the spec calls for a Cl 125 FF Gate Valve, then use a Cl 125 FF flange.

If the spec calls for a Cl 150 RF Gate Valve, then use a Cl 150 RF flange.

The flange must be appropriate to the valve end, if 150 RF – 150 RF etc.

Actually, the bolt dimensions (BC and diameter) are equal between the two flange classes in 8″. The most important issue is that both flanges need to be FF. As long as the valve manufacturer’s bolt torque requirements are met, the suggested arrangement should work fine.
RF to FF arrangements can cause gasket problems and cracking of the DI or CI FF flange, since RF flanges are typically steel.

Tim Storey

[timstorey]

If the spec calls for a Cl 125 FF Gate Valve, then use a Cl 125 FF flange.

If the spec calls for a Cl 150 RF Gate Valve, then use a Cl 150 RF flange.

The flange must be appropriate to the valve end, if 150 RF – 150 RF etc.

Actually, the bolt dimensions (BC and diameter) are equal between the two flange classes in 8″. The most important issue is that both flanges need to be FF. As long as the valve manufacturer’s bolt torque requirements are met, the suggested arrangement should work fine.
RF to FF arrangements can cause gasket problems and cracking of the DI or CI FF flange, since RF flanges are typically steel.

Tim Storey

[Author]

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