daveboy
Mechanical
- Aug 5, 2002
- 27
I would appreciate some of your opinions on the below.
We are quoting a API 16C manifold.The design is 10K upstream of the chokes 5K downstream of the chokes. Two hydraulic chokes and one manual choke. From the chokes all connections go to a buffer chamber rated to 5K. So all ok.
Our customer has now requested to add a bypass line between the upstream side of the manifold (10K) with double isolation gate valves to the buffer chamber (5K).
My concern (however small) is that if the two isolation valves are left open for what ever reason then the buffer chamber and all downstream items that are 5K rated could see the 10K pressure.
My collueges argue based on the draft version of API 16C - 2010 "10.13.2.2 This pressure rating shall in no case be less than that of the lowest rated connection to the bufferchamber and associated valves as applicable, nor of the downstream equipment."
Therefore the buffer chamber and everthing downstream of the chokes is rated to at least the lowest pressure of 5K eveything is ok - even with 10K vales directly onto the buffer chamber.
Regardless of what the standard says my humble opnion is that this posses, however small, a saftey risk.And argue based on API 16C 1st Edition and best engineering practice that "10.2.2 Rated Working Pressure.
The rated working pressure is determined by the lowest rated working pressure of the component or assembly,including integral end or outlet connections."
Therefore the manifold can only be rated to 5K as is and to rate to 10K one of the following needs to be undertaken
1. Rate the dowstream side of the chokes all to 10K
2. Remove the connection to the buffer chamber and leave this as a blind for our customer to connect to on site seperatleyYour opinions on this would be appreciated.
Simple P&ID of the system is attached.
We are quoting a API 16C manifold.The design is 10K upstream of the chokes 5K downstream of the chokes. Two hydraulic chokes and one manual choke. From the chokes all connections go to a buffer chamber rated to 5K. So all ok.
Our customer has now requested to add a bypass line between the upstream side of the manifold (10K) with double isolation gate valves to the buffer chamber (5K).
My concern (however small) is that if the two isolation valves are left open for what ever reason then the buffer chamber and all downstream items that are 5K rated could see the 10K pressure.
My collueges argue based on the draft version of API 16C - 2010 "10.13.2.2 This pressure rating shall in no case be less than that of the lowest rated connection to the bufferchamber and associated valves as applicable, nor of the downstream equipment."
Therefore the buffer chamber and everthing downstream of the chokes is rated to at least the lowest pressure of 5K eveything is ok - even with 10K vales directly onto the buffer chamber.
Regardless of what the standard says my humble opnion is that this posses, however small, a saftey risk.And argue based on API 16C 1st Edition and best engineering practice that "10.2.2 Rated Working Pressure.
The rated working pressure is determined by the lowest rated working pressure of the component or assembly,including integral end or outlet connections."
Therefore the manifold can only be rated to 5K as is and to rate to 10K one of the following needs to be undertaken
1. Rate the dowstream side of the chokes all to 10K
2. Remove the connection to the buffer chamber and leave this as a blind for our customer to connect to on site seperatleyYour opinions on this would be appreciated.
Simple P&ID of the system is attached.
