Removing of relief valves and the dangers you should be aware of

[applecache]

Hi

Just started to do a little bit more ammonia work and was removing relief valves from a liquid receiver.

What dangers would you make yourself aware of?

Do some people go to the extreme and have a fire hose ready in case it leaks etc

Thanks

[Brian_UK]

I never worked with NH3 but from what I've read and heard my answer would be that you should be aware of every danger that your training informed you of.

There are no shortcuts with dangerous and life threatening chemicals and pressure vessels.

[HwT]

Does the system use double shut of valves for the safety valves?

[NH3LVR]

HwT beat me to the part about dual relief valves.
I have never used a fire hose on a NH3 leak.
Also consider using rupture discs under the relief valves if they are not already installed.

[cricri]

15989

Hello,

I had to write a note about AWP relief valves a few years ago.
Their 3way valves are operating in reverse mode from the others (Parker, ....).
This affect GEA compressors units (square shape) and 3wayvalves on vessels (round shape).
Normaly a sticker on it indicate the operating mode.

It's a bit dangerous, had to face some almost accidents on field.

[RANGER1]

Pop
15989

Hello,

I had to write a note about AWP relief valves a few years ago.
Their 3way valves are operating in reverse mode from the others (Parker, ....).
This affect GEA compressors units (square shape) and 3wayvalves on vessels (round shape).
Normaly a sticker on it indicate the operating mode.

It's a bit dangerous, had to face some almost accidents on field.

Thanks Cricri, definitely a trap for anyone who assumes they know something.
Never seen one in Australia myself, only singles.
Good information

[applecache]

Yea I see that now with the diagram you posted. Most of the time I’ve come across where you have to back seat it to take it off and vice versa thanks for the time and info.

[cricri]

for clarification, you should now see on the 3ways valves this sticker....if not painted!15991

[RANGER1]

If you did not have to do it, I would call in a company that specializes in ammonia.

[applecache]

Thanks for all the tips. I definitely used the bubbles to see and judge how much ammonia was coming out of the 3 way valve. Especially useful when you have a full face respirator on and cant smell it.

[applecache]

Oh I should add that whilst I was removing a relief I accidentally turned the threaded 3 way valve assembly a little. The reliefs were on the liquid reciever so it was not good. SO there is also another danger.