Double wall pipe (exterior) for fuel oil

No standard anywhere I know of for pipe. The only double wall standard I ever heard of is for ocean going tankers.

I guess you don't want any more cross country pipelines carrying fuel oil then.. ey? Will that also apply to diesel, gasoline and jet fuels and LPGs? Any exceptions?

What is a logical reason for a requirement like that? I mean other than the above. BP's latest spill on the slope?

Going the Big Inch!

I should have specified that I meant service from a building oil tank to buildings (99% of bldgs up here are on oil). Some portions of external oil piping in other services, say in tank farms where supply or resupply lnes are buried at road crossings, are double wall.

Buried lines at tank farms or resupply lines (ie from barge dock) are single wall with cathodic protection. Aboveground lines there are generally singlewall with cathodic proection.
We specify double wall horizontal tanks for aboveground fuel oil storage for building services, and for fuel storage in our tank farms. However we have some single wall vertical tanks in farms (as well as older single wall horizontals) , and they are of course provided with bermed containment with liner, geotextile, etc.

We do have diesel and jet A-1 storage in tank farms too but we use single wall pipe and cathodic protection.

Got it. Had me worried.

I think the pipeline industry in general has found that cased pipelines, especially cased road and railroad crossings, cause more problems (corrosion) than they avoid. During the 80's Northern Natural Gas in particular and many others were trying to avoid casing any crossing. Most pipe owners bulk plants, refineries, refined product storage plants and pipeline companies I know of now feel that pipe casing of any type prevents adequate inspection and therefore prefer well painted pipe supports that can be temporarily removed for easy inspection and a repaint whenever necessary. Its hard enough just to see under low pipe supports.

Going the Big Inch!

Yes that is right. Even in the small scale applications we are using here, inspection would be a problem. I think our Dep't here was being over-enthusiastic in interpreting current CCME and Environment Canada guidelines and trying to second-guess possible future changes .... When I spoke with Env Canada recently, they did not anticipate any increase containment for aboveground pipe. So now we are just doing single wall. And our poor consultant- who has spent a lot of time trying to find a suitable UL listed product- is going to be relieved, if a bit cheesed off at having spent a good deal of time on the research.

I think you'all will be better off without it. Just seeing the corrosion as soon as it starts is a big part of knowing when to inspect the rest of them and get them cleaned and repainted.

If he's a good consultant, he should just take the cheque, smile, and say thank you very much.

Going the Big Inch!