Double Flanged Dual Plate Valve - Length

[uaepiping]

Dear Piping engineers,
As per table 3 of API 594, the face to face dimension of double flanged dual plate check valve for 14"-1500# is 356mm. The bolt length for the 14"-1500# flanges is 405mm. So fitting two bolts with flanges at the ends is not possible.
Taking it other way:
The flange thickness for the 14"-1500# flange is 140. So adding these two flanges, we get 280, so remaining space is (356-280 = 76mm) in which two M56 nuts can not accommodate.
So is there a change on the API team's agenda to change dimensions of such valves?
My problem is to provide a note in our specification, in case valve in this size and rating range is required. Any help on that please?

 

[MickMc]

There are 2 sets of bolts required, one for each flange connection.

 

[LittleInch]

According to this site

http://www.wermac.org/valves/dim_valves_dpwc.html

the dimension you quote is for a wafer check 14" class 1500 valve, i.e. if fits between two sets of flanges.

It looks like all the class 1500 valves won't accommodate two flanges.

The spec notes that double flanges is only available "where the nut space allows", Clearly here it doesn't hence these types of valves are used ..

http://www.advancevalves.com/double-flanged-dual-plate-check-valves.aspx

Alternatively you could get the bolt holes tapped to the size of bolt you want and screw it in form the other side to the same depth as the nut, but this is not common.

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

 

[uaepiping]

Dear LittleInch,
Yes at the moment this - the link that your provided - is the solution for valves in this size (and rating) range where two nuts can not fit in the space between end flanges.
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Any idea/information if API is planning to revise their dimensional table?
How should we cover this in our spec?
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For the spec may be we can add:
"For double flanged, Dual plate valves, refer API 594. In case the valves as per API 594 have such dimensions where two nuts can not accommodate between the end flanges, valves from other sources shall be specified/procured (subject to COMPANY approval)."

 

[LittleInch]

The second link I think gave the sizes and class rating where double flanges with "standard" 594 dimensions doesn't work ( including all #1500 sizes). Maybe just cut and paste in that table?

Normally these types of valves are not double flanged, but wafer installed. If you want flanges then use a swing check or a valve type which is designed to be flanged. I doubt API are going to revise their table for one particular valve type, but they might insert that table. Why don't you write in and ask them / tell them it would be a good idea to be a bit more precise than simply "where the nut allows..."

You don't normally save anything by having to use "special" bodies.

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