Anhydrous Ammonia PSV's

[fritz103]

The OSHA Standard CFR 1910.111 states that NH3 PSV discharge tailpieces shall have suitable raincaps. Any ideas?, we have considered a hat type, or turning the discharge 90 deg with a bevel cut.

 

[EGT01]

I have no experience from a cost or maintenance aspect but seems I've seen the "sock" type used quite a bit. Not necessarily this product but one similar.

http://www.prdtechnologies.com/id53.htm

 

[jalvarez]

Fritz:
Just use a weatherproof piece of fabric tied with an elastic. If the valve blows, it will be removed.
I don't recommend to turn the discharge direction, as you need to evaluate where to discharge. Further, ammonia diffusion will be very affected.
Have a safe day
J.Alvarez

 

[CHD01]

Plastic Raincaps can be purchased off the shelf from rupture disc and vent manufacturer's. Try BS&B rupture disc vendor page on web. Do not turn the vent or use a bevel cut on the vent as this will impose additional relieving forces on the discharge vent line requiring reinforcement, in addition to creating potential safety problems to personnel in the area.

The more you learn, the less you are certain of.