Can We Locate Flange Butter Fly Valve With Spacer Together?

You do not state the rating of the flange or what type of spacer you are planning to use. Is it a spectical blind or bleed ring or are you placing a custom spacer to make up room for the piping layout? However I can tell you that the problem is that the butterfly of the valve will not open entirly with a spectical blind or a bleed ring in some sizes. It is a general rule of Piping designers not to place a spacer between a buterfly Valve and the mating flange. However you can design a custom spacer with a larger bore to accomidate the opening of the butterfly. You may also want to check with the manufacture of the Butterfly valve for a definate yes or no.

I hope this helps.

Robert F. Laurin

Senior Principle Designer

Processes Unlimited International Inc.

Bakersfild CA. USA

rflaurin@prou.com

There is one very important issue that determines whether you can place a "Spacer" and a "Valve" (any valve) directly next to each other between the same two flanges. This issue is the design of the Valve itself.

Is the Butterfly valve (or any other valve) made with Flanges on both sides that will mate with the adjacent flange with a separate set of bolts (studs) from the set of bolts for the other side of the valve? With this style of valve body you can remove the downstream set of bolts, remove the spacer and replace it with a paddle blind and still have the upstream side under pressure.

or

Is the valve a "Wafer" style or "Lug" style that is held between the two flanges by a single set of extra long studs? With this style of valve body you cannot remove any of the bolts or the valve and the spacer will "Blow" out due to the pressure.

Please note: I could not find a 34" flanged Butterfly Valve.

Here is a link for Flanged Butterfly Valves:

http://www.goodvalves.com/Butterfly%20valve/Flange%20Type%20Butterfly%20valve.pdf

Here is a link for Wafer & Lug type Butterfly Valves:

http://www.goodvalves.com/Butterfly%20valve/Wafer%20Type%20Butterfly%20valve.pdf

You can do what you suggested in your original question but you must :

(a) select the right style of Butterfly Valve

and

(b) make sure that the inside diameter of the spacer does not interfere with the disk of the Butterfly Valve

Thanks for your reply.

Valve size is 36" and we got the offer for flange type butterfly valve. as u said, seprate set of bolts on the other side with the spacer. We have taken care of the inside diameter of the spaer that does not interface the disc.

With the above arrangement, I think we can directly place the spacer on the butterfly valve and avoid addl set of flanges.

Thanks.