Re: [PipingDesign] Carbon steel ASTM 216 grades WCB & WCC

From: <Christopher>
Date: Sat Jan 26 2008 - 16:43:00 EST

On Jan 26, 2008, at 3:06 PM, M. Engineer wrote:

> Can someone state the difference between the grades of
> WCC & WCB of carbon steel. One valve manufacturer
> proposed to supply us with carbon steel valves ASTM
> A216 Gr. WCC instead of the original request of having
> the valves bodies made of ASTM A216 Gr. WCB. What is
> the exact difference between WCC & WCB. The valves
> shall be utilized in hydrocarbon service.
WCC has a higher yield strength than WCB to begin with.

Now for the lecture. When you get a counter-offer like this you've got to read both specs, assess all the differences and sort out the the significance to your particular project. No one on this list knows enough about your problems to give you advice in this area. you have to do it yourself. There's a reason why the valves were originally specified to fabbed from ASME SA-216 Gr WCB (*not* ASTM A216 Gr WCB--until you've verified that the ASTM spec and the ASME spec are identical in *every* respect! ASME Codes frequently restrict the scope of ASTM specs before listing them) You can't call up your boss or your client and say you're changing materials because someone you've never met who knows nothing about your project told you they seemed the same. Read the damn specs!

I'm going to keep repeating this little homily every time someone posts this to the list. It hasn't worked over the past several years, but who knows, someone may get the idea before he gets sacked for substituting gossip for engineering.

Christopher Wright P.E. |"They couldn't hit an elephant at chrisw@skypoint.com | this distance" (last words of Gen.

.......................................| John Sedgwick, Spotsylvania
1864)
http://www.skypoint.com/~chrisw/ Received on Sat Jan 26 16:43:00 2008

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