Lean Process
Chemical
- Feb 25, 2017
- 2
Hello.
I am looking into safe design of an offshore heating medium system using combustible heat transfer medium heated in a power generation turbine exhaust duct.
API 14C recommends a single FSV in the heating medium line downstream the Exhaust-Heated Component, to prevent backflow of combustible fluid into the exhaust heater chamber in the event of tube rupture.
In my experience as a process designer in the North Sea, a single FSV is considered to limit backflow only in an operational context. In the safety context I have specified two dissimilar FSVs in series as primary overpressure protection with a PSV as secondary protection. In this case I have further assumed that when a demand is placed on the FSVs, they will leak at a rate corresponding to 10% of the cross sectional area of the pipe in which they are installed.
In my experience as a process support engineer I have never come across a performance standard for regular verification of FSVs, such as would be applied to ESD valves in hydrocarbon service.
So now I am inclined to specify an ESD valve in the heating medium line instead of FSVs, since backflow of heating medium would risk escalation of a fire event in the exhaust heater chamber.
Any comments please folks?
I am looking into safe design of an offshore heating medium system using combustible heat transfer medium heated in a power generation turbine exhaust duct.
API 14C recommends a single FSV in the heating medium line downstream the Exhaust-Heated Component, to prevent backflow of combustible fluid into the exhaust heater chamber in the event of tube rupture.
In my experience as a process designer in the North Sea, a single FSV is considered to limit backflow only in an operational context. In the safety context I have specified two dissimilar FSVs in series as primary overpressure protection with a PSV as secondary protection. In this case I have further assumed that when a demand is placed on the FSVs, they will leak at a rate corresponding to 10% of the cross sectional area of the pipe in which they are installed.
In my experience as a process support engineer I have never come across a performance standard for regular verification of FSVs, such as would be applied to ESD valves in hydrocarbon service.
So now I am inclined to specify an ESD valve in the heating medium line instead of FSVs, since backflow of heating medium would risk escalation of a fire event in the exhaust heater chamber.
Any comments please folks?
