Sentinal valves are similar to Relief valve but only to warn about the rising pressue abov set point. corrective actios is required when this valve signals increase in pressure.

Post a Reply...

These are normally safety valves or safety relief valves and not relief valves.

Post a Reply...

A sentinal valve should not be described in any terms of relieving pressure.
It is a pressure operated valve with a progressive action so that it partly opens at its setting then opens further in proportion to the rising pressure.
The discharge of the valve is fitted with a whistle or horn which increases in volume with pressure.
Sentinal valves are likely to be fitted near the steam exhaust valve of back pressure turbines so that if the valve is being closed by mistake the whistle will warn the operator to stop closing and reopen the valve. They may also be used on high platforms eg Dearator domes where it avoids scaring people in danger off falling when a safety valve operates.
Small safety/relief valves can be used for this purpose provided they are tuned for hydraulic service and not steam, so that they remain proportional to pressure in their flow.

Obviously they are set to operate before the equipment safety valves operate.


Post a Reply...