Pressure Relief Valve - Indication of Opening 1

[Blink1873]

Hello

I am being asked to provide instrumentation that alerts when a PRV has opened. My inital thought process was to use a flow switch (at minimum setpoint) in the discharge line but I do not know if this will provide a reliable result. My understanding is that a flow switch will require the discharge line to be completely filled with fluid and I am not confident this will happen if the PRV does not reach full lift or the system pressure quickly reduces below the blowdown and the PRV reseats.

Does anyone hae any ideas or history with a similar scenario?

Cheers
Blink.

 

[RVAmeche]

What is the relieving fluid? What are the applicable overpressure scenarios?

Is the discharge line tied into a relief header or other equipment, or is it straight to atmosphere?

If straight to atmosphere, a flow or pressure switch may work​

Do you have a rupture disc isolating the PRV inlet?

If yes, a burst indicator/tell-tale indicator between the RD & PRV is an option​

 

[Latexman]

I am being asked to provide instrumentation that alerts when a PRV has opened.

Why? Action needs to be taken BEFORE it opens.

It seems to me that if a certain PRV was important/toxic/hazardous enough to have an alert when it has opened, it would already have instrumentation to:
[ul]
[li]Pressure transmitter with data recording - so anyone can see what the process pressure is doing.[/li]
[li]High pressure alarm - when a little above the normal operating range.[/li]
[li]High-high pressure interlock/shutdown - higher pressure above the normal operating range, but below PRV set pressure.[/li]
[/ul]

That is where the operators and Engineering Controls need to be taking preventative actions.

Good Luck,
Latexman
Pats' Pub's Proprietor

 

[don1980]

Most spring PRV manufacturers offer lift detectors as an option. The bonnet cap is removed, and this lift sensing detector is mounted on that same connection - no valve modifications needed. Alternatively, sound transmitter can be used. This the least expensive method because the sound sensor is mounted on the outside of the pipe (tailpipe).

Information on all of these options can easily be found on the internet.

 

[MJCronin]

A very good and informative article on this subject:

http://www.valvemagazine.com/magazine/sections/features/9640-monitoring-pressure-relief-devices.html

Emerson and Rosemount offer wireless devices and systems that monitor valves and detect Acoustic emissions.

They are mounted on the tailpipe of the PRV .... Temperature can also be monitored as a secondary confirmation

https://www.emerson.com/documents/a...ssure-relief-valves-monitoring-en-5397656.pdf

https://www.instrumart.com/assets/708-datasheet.pdf

MJCronin
Sr. Process Engineer