Mechanical Design of ball valve

[nightfire007]

we purchased some ball valves from one of the factories as follows :

1- 18"-Class 600- Flanged, Top entry ball valve, F.B:
2- 18"- Class 600- Flanged, Top entry ball valve, R.B:
3- 20" –Class 600 –Flanged, Top entry ball valve, R.B
4- 24"-Class 600-Flanged, Top entry ball valv, R.B



during the inspection we found out that they use the the design in the attachment( figure 1) during manufacturing, but following to my conversation with other factories they said that the proper design would be as the attachment ( figure 2),

since we performed the hydrotest on the valves according to API 598 and the result was factory, is it possible that we encounter any problem during operation of the valves in the line pipe. ( maybe since the seat is not blocked in the seat ring)
is there any common practices which force the manufacturer to use this kind of design ( putting the step for fixing the seat in the seat ring)

you can see the attachment in below link

http://www.fileconvoy.com/dfl.php?id=g4f77b9c7347c3013999195547ebe3eb54cfa96092

 

[ElSid1]

Attachment not working
Did the specification did not call for a "blocked in seat"?

... following to my conversation with other factories they said that the proper design would be as the attachment ( figure 2)

I've been in a situation where the losing contractor had a way of badmouthing the winning bid.
In short, if the specifications call for the blocked in seal, you can request new valves since the supplied valves do not meet the spec. If not, and you don't feel comfortable, this will be a change order.
BTW, you never gave the fluid, pressure or any other parameters which all affect valve selection.