Unknown symbol - Geothermal steam piping

[KristjanGerhard]

Hi all

I'm assisting my geothermal colleagues and came across a symbol I don't recognize. Can anyone tell me what this symbol means and from what standard it is derived?

Thanks

 

[EmmanuelTop]

It's hard to guess when the detail is taken out of context but this could be a symbol for balancing control valve used in HVAC and tempered water distrubution systems. See the symbol at

http://www.cfm.va.gov/til/sDetail/Div23HVACSteam/SD230511-17.pdf

and more details at

http://www.bssindustrial.co.uk/download/575/ASV-PV family.pdf

Dejan IVANOVIC
Process Engineer, MSChE

 

[LittleInch]

My guess is either a soft close non return valve or one that can be held open.

This is a made up symbol so you need the symbol sheet to be sure. No note next to it?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[KristjanGerhard]

@EmmanuelTop: I had seen that chart, it's the only symbol vaguely similar to this one.

@LittleInch: I think it must be some form of check valve based on the location in the system.

It's on the discharge of each cooling pump and on the return leg from the heat exchangers, where the bypass branch is connected.

There is no note or legend.

 

[BigInch]

Looks like it could be a "cycle stop" valve. Transient pressure controlling valve.

 

[bimr]

It is most likely a Booster Pump Control Valve, a diaphragm actuated active check valve that opens fully or shuts off in response to electric signals. It isolates the pump from the system during pump starting and stopping, to prevent pressure surges.

 

[KristjanGerhard]

@bimr: Sounds reasonable. Any thought on the origin of the symbol?

 

[Gator]

I'm going to guess spring-loaded check valve.

Piping Design Central

 

[LittleInch]

There's no electrical or instrumentation signal or actuation on it. For a parallel pump or indeed any pump you would expect an NRV on the discharge line - this is it, there isn't another one.

I'm going with a soft close NRV having seen the diagram.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[BigInch]

$10 bet that it is.

 

[bimr]

Don't know where this symbol came from. This fellow has the exact same symbol listed as a dual-plate check valve.

 

[Gator]

But the 's' appears also on the butterfly valve, hinting that it refers maybe to a wafer-style body. I don't recall seeing that symbol for a butterfly valve either, though.

Piping Design Central

 

[LittleInch]

Bimr,fair enough.

Kristjan, Like I said, find the symbol sheet.

Quite why you need to make this distinction on a p& id, I don't know.....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[BigInch]

LittleInch did you lose my $1 bet?

 

[bimr]

I agree with LittleInch that unless the detail is important to operation, not every detail needs to be shown on the P & ID. This is something that can be handled with a valve schedule in the specifications.

In addition, you should confirm with the owner of the P & ID what this item is.

 

[KristjanGerhard]

I queried the designer and it's a spring loaded NRV.

The exact type of valve isn't important, however i needed to know the function of the valve.

Thanks guys for your input.

 

[BigInch]

Just a check valve with a spring load against the flapper or ball to hold it closed until a constant positive flow is assured. This prevents the valve from opening too early when flow might be variable and cause fluttering or chattering, or amplify waterhammer.

 

[Gator]

Yay for me.

Piping Design Central