Flange Drilling

[rajeshnair1977]

Hi engineers,

In Class250 Raised Face Flange - It is Possible to Drill ASME B16.15 Class150

Regards
RAJ

 

[LittleInch]

Class 250 is Cast Iron usually so no yo can't mate it to a class 150 flange, especially RF, I don't know how you've got an RF flange in cast iron and drilling it is not permitted.

Also the number of bolt hole in a class 250 flange is often a lot more than a class 150 flange. so it wouldn't seal or will break when you tighten up the bolts.

This is a very bad idea IMHO.

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

 

[rajeshnair1977]

Thanks for your response.

Actually manufacturing is supplying the Gate valves with Class250 Raised flange.

Question from EPC Contractor : Drilling of End Flange should be - ASME B16.15 Class150
( Its possible comply the above comments )

Regards
RAJ

 

[LittleInch]

It's B 16.5, not .15.

Just tell them to buy a class 250 flange.
Or buy a valve with class 150 flanges

Do not start trying to make something fit by drilling any flanges

And find out EXACTLY what the valve flange is. "Raised Flange" is not Raised Face. Usually CI flanges don't have RF capability as the just break or crack when you tighten the bolts.

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

 

[geesaman.d]

Actually manufacturing is supplying the Gate valves with Class250 Raised flange.

Question from EPC Contractor : Drilling of End Flange should be - ASME B16.15 Class150
( Its possible comply the above comments )

The EPC Contractor is sloppy and wrong, assuming you didn't introduce any typos.
- The dominant "150#" flange standard is B16.5
- B16.15 contains a 125# or a 250# and is for cast copper alloy threaded fittings. It does not contain a 150# class and there is no drilling, no raised face.
This goes back to the EPC Contractor now to correct this nonsense comment.

Do you own copies of the standards mentioned in the project, and if not, how do you plan to execute the order correctly? I suspect you don't because you're asking us. Fix that problem.

If it's intended to be B16.5 150#,
You may need to pay for an upgraded valve also to get the B16.5 150# flange implied by the EPC Contractor. Not all flanges are available on all product models, materials, at the same cost.

Emphasizing what LI already said - never mix and match drill patterns with flange standards. Raised face flanges have significant gasket preloads and using the wrong drilling / fasteners will crack or bend flanges and damage gaskets.

I deal with this problem regularly - the original customer specs / datasheets are sloppy with the flange specifications; the customer pushes the order along with our proposed best guess of the intended flange specification and on submittals, we encourage the customer to review the flange details. Way too far down the approval process, often after shipment, someone finally reads the GA drawing and the customer ends up paying for a change order. Customers get upset when change orders delay the project and cost more than they would have cost at bid and, but they're also paying for all resources wasted up to that point. The customer has also burned any opportunity to receive favors. This laziness costs a lot of money and time they could have saved had they just verified the flange specs the first time!

David

 

[LittleInch]

Lets just get this correct though.

ASME B 16.1 is the standard for cast iron flanges, which is what the OP says he has, class 25,125 & 250
ASME B 16.5 is for steel flanges, classes 150,300,600,900,1500 & 2500
ASME B 16.15 is for copper alloy (bronze) flanges classes 125 & 250

But agree with geesaman. Someone somewhere has not read the specs properly.

Who is buying what here?

Are these valves actually ductile Iron and not cast iron?

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

 

[geesaman.d]

I didn't see any reference to 16.1 or cast iron.

I agree when I see 125# and 150# gate valves being tossed around, I'm thinking 16.1 or 16.5 but that's my bias talking.

Just another example of how wasteful inaccurate flange specs are!

 

[LittleInch]

Fair enough, that was my assumption of a typo as it doesn't make sense - "It is Possible to Drill ASME B16.15 Class150" as there is no B16.15 class 150....

Never actually knew there was a B 16.15 before now...

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

 

[rajeshnair1977]

Gate Valves , Ductile Iron Body ASTM A536 ,Gr.70.50.5 c/w Class250 Flange ASME B16.1

 

[LittleInch]

Good,

At least you can have a DI RF flange.

You still can't drill it to ASME B 16.5 class 150 if the holes are already drilled for a B16.1 flange. ( Are they drilled already?)

Just buy a B 16.1 flange in steel or tell the contractor to buy one.

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

 

[GBTorpenhow]

A standard B16.5 Class 300 flange will mate with a Class 250 flange.

There is some guidance in B16.5 about this sort of situation that would be worth checking if going this route.

 

[LittleInch]

GBT, you're talking too much sense!

Now you'll have a class 300 flange on a class 150 system. The world will collapse due to this mismatch

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