King valve

[nanuuk]

Can some one tell me if it is a good idea to have your King Valve shut everytime your engine room shuts down on load for a 2 stage Nh3 plant? Or should it remain on during these cycles? Thanx for your time.

[Rob White]

Can some one tell me if it is a good idea to have your King Valve shut everytime your engine room shuts down on load for a 2 stage Nh3 plant? Or should it remain on during these cycles? Thanx for your time.

King Valve is not a term that we use much in the UK but
I understand it is the main valve on the liquid reciever?

So if the system shuts down how is this king valve activated?
Is it automatic or manual.

If you are shutting down the engin room then I would close the valve
put all the liquid in the reciever and than after turning the plant
off I'd close all other valves as well.

If the machine is just cycling on and off then if the valve is manual
no I would not close it.

It depends if the valve you are refering to is a hand opperated one
or a fully automatic valve.

Regards

Rob

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[nanuuk]

Hi Rob thanx for the response we have both on our liquid line coming from the reciever 1 is a manual v/v at the receiver and upstream is a electronic pilot v/v which will only go off by a on/off switch, a power failure or too low a level in the receiver. The pilot v/v is just a easy safer way to shut off the v/v incase of a emergency where we have warehouse staff trained to do this if there is no engineer on sight and they can do this without having to enter the engine room don't need a person panicking with a pipe wrench closing a manual v/v if you know what I mean. I was just wonedering if there would be any concerns if the pilot valve cycled with the engine room on load which by the way happens around 15 times a day and up to 1/2 hour the engine room will be off thanx again.

[NH3LVR]

I see no reason why it would be to your advantage to close the King Valve during an off cycle. In a system such as yours it would most likely not cause a problem, but create no advantage.
Where you would get into trouble is if you got into a pump down condition and the cpmpressors could not start because of low pressure and the electric King Valve could not open because no compressors were running. Not too likely to happen in a NH3 system of any size.

[Nh34life]

This all depends on whether you have automated level control of your IP accumulator, if say it is running a float pilot or modulation valve technically it should not cause any issues however it would be good practice to shut this "king valve" to avoid any high levels or equalisation if there were to be any failures of your level controllers. obviously if your IP vessel make up is feed from a hand expansion valve shutting the king is a great idea!

[Rob White]

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As the others have said, you could close the valve but there would be no
real advantage unless it was for the safety aspect of knowing where all the
gas is.

If it was me, I would set it up and run the plant for a week with the valve
closing and then compare any differances with a week of no closed valve.

Regards

Rob

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