socket welded end valves

[mkp]

i have got an offer for socket welded end bellow sealed globe valve from a german company aws follows
1 . valve size - 1/2 ' to 1 1/2"
2. Valve class rating :- class 300
3. valve material :- ASTM A 105
4. Ends :- Socket welded type

Can the valve class be correct.

the party is a reputed german company

what should be the minimum class as per DIN standard for Socket welded valves as per ANSI B 16.11

 

[way]

I agree that a class 300 valve does seem strange for a Socket Weld Valve. You might ask them if they forgot a zero.

Anyway you look at it, you still need to match the right valve to your application. If you are using schedule 80 pipe, you will need valve and fittings in the 3000 class. If you are using schedule 160 pipe, you will need valves and fittings in the 6000 class.

Hope this helps, and good luck.

 

[MikeONeill]

Currently produced bellows-sealed globe valves are produced to API Class 800 at minimum. B16.11 covers socket weld dimensions. B16.34 is relative to pressure class. Bonney Forge, Edward Vogt, OMB, and a variety of other manufacturers produce Class 800 valves in A105 quite economically.

Mike

 

I would agree with Mike, I would say that class 800 is the minimum standard that I have come across and I would be very careful of buying something rated lower than this, it could be totally incompatable with your applied pipework. The other point worth bearing in mind is that a lot of far eastern manufactured goods are described as "class" rated when in fact they are the actual working pressure in psi, for example a 1" bsp class 200 globe valve would in fact be a globe valve suitable for 200 psi working pressure. This can be extremely misleading so I would request a temp/pressure graph from this supplier first.
Regards
AndyS

 

it is 800# for sw/bw joint. API 602 says so.

 

As per other replies,

SW by European Manufactures built to 800# spec, ie SWG etc, some times shown as 300#

As not aware of this supplier 90% of Forged Manufactured in Italy OMB, Bonney Forge, LVF cover 80%

Regards

 

[JGPeck]

I would like you to consider as well 3 other points:
1- No German manufacturer currently produces API602 SW valves as standard. They may have taken a standard DIN globe valves and cut up the flanges to offer a SW version. A DIN PN25/40 would then become a class 300 ANSI.

2- quoted rating for the valves may be the rating of the bellows (body may be class 800 to API602 design, but bellows with single wall therefore rated at lower 300 class to BS std). Most of German manufacturers make low pressure sigle wall bellows only (for Steam service), while the in Italy we manufacture mostly Bellows for petrochemical uses, thereofore class 800 min. (3 walls bellows)

3- If 300/600 design is acceptable a chep alternative would be OMB Ecolvalve or Spirax Sarco similar A3S valve