ISO 15848 part 1

[alby87]

Dear All,

if i'll test a gate valve as per ISO 15848 part 1, is it possible to qualify even globe valves and other valves with the same packing and body/bonnet gasket design?

Alberto

 

[reverman]

No. unless you key the globe valve stem to prevent rotation. Typically globe valve stems not only have linear movement but they also rotate. see paragraph 8.c of ISO 15848 part 1. The motion of the shaft must be identical.

 

[alby87]

Thanks.. My problem is that on paragraph 8 of ISO part 1 it is write that the qualification is extended to valves of the "same type" but it is not define the "same type". Talking with TUV they say that gate is equal to globe if they have the same movement of stem (i.e linear rising, not rotating). on the other side some customers read the sentence like that gate and globe are different because of design construction.
So i cannot find an unique interpretation of the first sentence of paragraph 8, and i would know if both interpretations are correct or not.
I mean, ISO define in my opinion the design of the sealing and not of the whole valve, so i read "same type" as TUV interpretation; but it is correct even the second interpretation....