Valve Requirement on Tank

[302Hugo]

I wasn't sure if this question is better suited in here or just in the pipelines/piping forum.

I have a question regarding welded tanks for oil storage (100,000 bbl in this case). I am in Alberta CA. We are looking to install piping off an 8" nozzle on the tank. However, at some point someone had a smooth idea to drive a pile about 2' away from the nozzle and put up cable tray.

So my question is if there are any code/standard requirements that state a valve must go on the nozzle before piping, or will we be able to put a 90deg ELL and then a valve?

Even then, I'm almost reluctant to do this just in case the ELL was to ever fail, we would have no way to block that tank nozzle. Or because the chance of that elbow failing is "slim" I shouldn't worry?

Thoughts?

 

[SNORGY]

I would have no issues with the elbow.

It's done on the outlet drains on pressure vessels and scrubbers all the time to avoid a fugitive emission source inside the skirt, for example. Those kinds of elbows would fail far sooner than elbows on an API tank.

There may be an API-650 clause against it somewhere, but I doubt that even if there was and you didn't follow it that you would be in much trouble.

Regards,

SNORGY.

 

[Duwe6]

API 650/653 is 'silent' on this, as it is past the tank boundary. Any piping Code will allow you to put the valve anywhere you want. Just be sure to support the pipe such that the nozzle does not carry the weight of the pipe & valve. Tanks are fairly delicate.

 

[tr1ntx]

I've seen elbows on nozzles on a lot on oil storage tanks (much smaller than your's), separators, pressure vessels, etc. I'm not saying it was the correct thing to do code-wise, but it's been done a lot.