Control Scheme
Control Scheme
(OP)
All:
I am new to the process industry.I am working on LNG project in the development of P&ID's. I am trying to understand the logic (or undertsand how it is trying to control) for 2 valves HV-1000 and HV-500 marked w/ an arrow in the attachment.
A sequence of operation would be good way to understand.
Your help would be appreciated.
See attachment
Regards,
npf
I am new to the process industry.I am working on LNG project in the development of P&ID's. I am trying to understand the logic (or undertsand how it is trying to control) for 2 valves HV-1000 and HV-500 marked w/ an arrow in the attachment.
A sequence of operation would be good way to understand.
Your help would be appreciated.
See attachment
Regards,
npf





RE: Control Scheme
The HZSO/HZSC are open/close limit switches. The HY pointing to the solenoid valve is a fail safe interlock from an SIS system.
Nothing at all to indicate what the valve is controlling.
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This is normally the space where people post something insightful.
RE: Control Scheme
One 4-20 ma to the I/P or into the positioner for modulating control of the valve (usually this is the output signal of a controller).
The second signal is an ON/OFF signal to the Solenoid valve which will allow the pneumatic output of the positioner to get to the actuator and make it work.
Regards
ilan
RE: Control Scheme
Thanks for the responses.
Regards,
npf