Ball Valves for isolation of Radar level instrument at Tank top


Thread Starter


At the top of tanks where the Radar level instrument is located, is there a requirement of TRUNION type ball valve to provide isolation of the instrument??

Whether normal ball valve can suffice?? or if there`s no requirement of this ball valve at all??

On what basis these valves are specified??(like for high pressure tanks..etc)

Why do you need to isolate it? or actually what are you isolating it from? There is no need for isolation as far as i know. We have installed RTG3930 radar level transmitters and no isolation valves are installed. What is your application, hazardous or non-haz area?
What is the product handled in the tank? Is it hazardous? Is the tank under pressure? Do you need to prevent fugitive emissions during an RTG service?

The area classification should not matter (hazardous or otherwise) as the device has to be powered off before removal from tank.

Answers to these might be a clue.

Tanks at atmospheric pressure handling non hazardous products do not require an isolating valve.

Tomy Zacharia
These are crude oil/product tanks & as far as i know there`re no fugitive emissions. This valve is there just to provide isolation to the instrument.

What is the normal practice? Where do we require a trunion ball valve?

For Anri
When did u install it? how long has it been in operation?
They have been in operation for over a year. as you mentioned, we use also use it in crude oil/diesel tanks. We had maintenance checks, replaced one(out of 16 RTG's). Your only concern is HC vapors(hazardous subs.). Spark free maintenance will do it without any isolation.

I suppose your tanks are not at high pressure- they usually not - so they don't need it.