Industrial ammonia refrigeration “KING” valve?

[RANGER1]

On a large scale 2 stage liquid overfeed (liquid recirculating), what would you define as a “KING” valve.
Is it just liquid line stop valve out of liquid receiver?
It seems pretty open to interpretation ( for me anyway).

Any opinions out there?

[NH3LVR]

The valve leaving the receiver was always what we called the King Valve. Of course different areas may us different terminology.

[Tycho]

The valve leaving the receiver was always what we called the King Valve. Of course different areas may us different terminology.

That's what I have heard, it's the quick closing valve on the HP liquid line.

I Norway the rules (DNVGL for ships) state that there should be a quick closing valve on any line leaving the compressor room.
On the main return there has to be a NRV bypass valve to allow liquid/gas to migrate back to the LP vessel.

The valves are activated by the gas alarm system or by hand.

There is a panel outside every entrance to a compartment with NH3 equipment.
1 button activates (closes) all valves on lines that has NH3 leaving the compressor room
1 button activates (closes) the main return valve.

gas alarm at 350ppm stops the nh3 pumps and closes valves on all lines leaving the compressor room, 1000 ppm closes the main return.
1000 ppm in the compressor room blacks out everything, and the valves are NC

[Tycho]

Found this
king valve.jpg

[RANGER1]

Thanks NH3LVR, Tycho.
I understand it more for a simple ***** system.
Closing this “King” valve is something, but not going to save the day in my opinion.
Seems like an old term.
Anyway, just marking up a schematic P&ID, keeps it simple.

[Tycho]

Thanks NH3LVR, Tycho.
I understand it more for a simple ***** system.
Closing this “King” valve is something, but not going to save the day in my opinion.
Seems like an old term.
Anyway, just marking up a schematic P&ID, keeps it simple.

Ranger, I don't like the term "king valve" besides it would really only work on plants that are DX, where the HP receiver is sized to accept the entire refrigerant charge.

The schematic I posted earlier was for a pump circulated plant.
Like I mentioned earlier, I would place the "quick closing valves" around the LP drum and not the HP drum on this type of systems.

On the plant's we install on ships, the HP receiver has a volume of maybe 50 liter and the LP receiver can take 8000 liter.

so it all depends on the plant really.


I'm against giving a valve a "Nickname" in the industry it's kind of the "Jesus nut" on a helicopter, the name implies that it's important, but anyone that hasn't been educated as a helicopter pilot wouldn't know where to look for it.

Jesus nut, or Jesus pin, is a slang term for the main rotor retaining nut which holds the main rotor to the mast of some helicopters, such as the UH-1 Iroquois helicopter; or more generally is any component that represents a single point of failure with catastrophic consequences.

And personally, I'm struggling to see the benefit of a single automatic shut off valve on the HP liquid line on any NH3 system... but that's just me

[marta5]

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