Safety Valve Installation
Safety Valve Installation
(OP)
Members,
We are strugling to find the API criteria for dual safety valve installation using two separate branches with two individual safety valves and isolation block valves upstream of each (one locked open while the other may be maintained). Each valve is sized for full capacity. This is not the classic three-way valve with 3% max dual safety valve setup.
Is the two branch arrangement within API 520 code compliance as long as there is a site procedure in place for lock-out?
Thanks for any guidance on this.
Regards,
Dan
We are strugling to find the API criteria for dual safety valve installation using two separate branches with two individual safety valves and isolation block valves upstream of each (one locked open while the other may be maintained). Each valve is sized for full capacity. This is not the classic three-way valve with 3% max dual safety valve setup.
Is the two branch arrangement within API 520 code compliance as long as there is a site procedure in place for lock-out?
Thanks for any guidance on this.
Regards,
Dan





RE: Safety Valve Installation
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RE: Safety Valve Installation
I believe you are agonising about having two independently connected parallel PSVs protecting same vessel. If so, provided you have taken care of keeping one PSV always available, there should be no problem. How is this different from parallel PSV's mounted on same header (consider the vessel as the header...)
Helps..?