Control Valve Tagging Question 2

[greg2013]

Could someone point me at the proper specification that says how a Control Valve should be tagged? I have had disagreement between if a Pressure Control Valve with an electronic controller should be tagged PCV-1234 (pressure control valve) or PV-1234 (pressure valve). I have been told the PV means it has an external control of some type like an I/P, and PCV means it is self controlled like a regulator. I cant find out if this is opinion or if there is a Spec somewhere that says that.
Any help appreciated.

 

[MortenA]

There is no universal rules for tagging. your company may have a system and there are some generic system e.g. NORSOK.

 

[LittleInch]

I prefer not to tag control valves as pressure, flow, temperature etc, but just CV as it then varies by what ever control input, which can be more than one input. tagging schemes vary didely, but are usually listed on the P & ID schematic pages which each company / project issues as the standard sheets for what each symbol / line number etc means.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[MatthewL]

LittleInch,

Exactly what I was thinking about the P&IDs. Star for you!

Greg2013,

Another problem with using PV is when the DCS control tags are assigned. PV in a DCS tag usually means Present Value, as compared to SP or Set Point and OUT or control OUTput (the signal sent to the valve). As LittleInch said, check the P&ID for the nomenclature standard at the plant.

Regards,

Matt

Quality, quantity, cost. Pick two.

 

[dcasto]

Actually I like using PVC/FCV 401 or PCV501. The operators really need to know what the purpose is The first I listed was a pressure control valve with a flow control over ride for example.

 

[LittleInch]

Each to his own I Suisse, but is the control system which really needs to know and three are many ways of showing this on a mimic or P&id without using so many letters.

Just my opinion though.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way