SW flange in Class 2500 3

[Fred Gh]

Hi Everyone,

I noticed there is no SW flange in Class 2500 of ASME B16.5. Does this mean that we can't/not allowed to have SW flange in class 2500? And if allowed, which part of standard can be referred to for dimensions?

Thanks in advance,
Fred G

 

[LittleInch]

It means there is no Socket Welded flange at class 2500 in ASME B 16.5

Having said that a quick google shows that a number of suppliers offer them apparently with "dimensions to ASME B 16.5" - presumably flange thickness and BCD, that sort of thing.

I would not personally envisage using a SW class 2500 connection. Too much risk for too little benefit IMO. I don't like Slip on flanges either....

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

 

[r6155]

SW class 2500, just a fillet weld????. NEVER.
SW is the worst design, try to avoid it.

Regards

 

[1503-44]

NEVER EVEN AT 150#
although they do make good handrail post supports.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[Fred Gh]

Thank you so much everyone for your responses.

So, I understand that not only for flanges but for all other fittings we need to define Buttweld connection on our CL2500 piping Spec. Just for more info Flange material is A182 GR F316/F316L and pipe is A312 TP316/316L. service is Hydrogen 245bar 65C DN15-DN40
We have CL1500 as well for CO2 and N2 with same material. Do you suggest buttweld for that class too?

Also, if you can please advise about valve. We need a small-bore ball valve. What is your suggestion about its type and endings in CL1500 and CL2500?

I appreciate your time.

Fred G

 

[r6155]

Nice material (stainless steel) with the best weld (butt weld).

Regards

 

[1503-44]

Do everything with butt welds. Everything.
No SO or Sockets. (Except for handrails).

For butt welded valves I always ordered them to be furnished by the supplier with short pipe pups welded to each valve end butt. That way it keeps the field welders from cooking any critical valve parts, as they only work on the pup welds.

Buy good valves for high pressure work. Trunnion mounted. Don't want the stems bending in the high pressure making them difficult to open. Similar to this one. I do not know this particular company, but it looks like a rather good product. UK mfgr. There are others, but I'd suggest this type. You can usually specify the bore as "Reduced port", or by providing actual port diameter, if you don't want "full port".

Just saw the DN 15-40, so this might be overkill, but you can see where I was going in the don't short valve quality route. A lever actuator, if manual, should be fine.

http://ogvuk.com/product/trunnion-mounted-ball-valve.html

Lots more here,

https://duckduckgo.com/?q=trunion+mounted+valve+stems&t=brave&ia=web

If you can tell us more, sizes, manual, motor actuated, emergency shut off service, criticality etc., maybe we can tell you more too.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[Fred Gh]

Hi Everyone,

r6155 Thanks for the compliment Also special thanks to 1503-44 for all shared information and links. Valves are manual and as I said DN15 to 40 is size range.

Thanks All,
Fred G

 

[LittleInch]

All this is specified in a piping spec which should be an off the shelf document from your engineering consultant.

Very high pressure high temperature Hydrogen doesn't seem like a project to be asking these sorts of questions. Do you not have anyone in your company to ask?

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

 

[Fred Gh]

Hey LittleInch, thanks for advice. High pressure piping classes need to be added to the Project PMS which currently covering lower than CL1500. So this is why I am asking these questions.

Also I preferred to ask here to collect more opinion of professional people in addition to internal resources.

Thanks

 

[georgeverghese]

Some 20years ago ( at least), socket weld fittings in process piping were blanket banned in the OpCo I worked at. This after several incidents with loss of containment of flammable fluids, especially on small bore connections in vibrating service.