Water in a diesel tank

[Colin Blackburn]

Hi,

I run a couple of diesel generators and the fuel supply for these is in the form of three linked 46 gallon oil drums on their sides. They are linked by 1 inch pipe at their lowest points. Diesel is periodically pumped into these tanks from a main plastic storage tank. Over the years, before we lived at the house, there has been some water ingress into the main storage tank. The pumping hose, therefore---I know realise, sits above the bottom of this main tank to avoid this water. However, I unwittingly pumped from lower in the tank than I should and thus put some water into the generator fuel supply tanks.

Two questions. First can I effectively drain off the water which sits under the diesel to the point where the fuel is usable? Or have I to write off the whole of the fuel and clean the tanks? As it is red diesel I can now see a 50-50 mix coming through after a couple of bucketfuls of almost "pure" water.

Second, one of the generators was running when this happened and thus quickly stopped running! Do I need to do anything other than run pure diesel through the engine or is it likely that further damage will have occurred?

Incidentally, the crap fuel tank is being decommisioned, hence the final disasterous pumping!

Colin

[Andy R]

Yes but still pump off the good diesel from an inch or two off the bottom.

That mix will gradually settle out although there's still an emulsion type layer which takes forever to disappear. That's why I suggested pumping the good stuff at least a couple of inches off the bottom.

Any damage that could be done has been done. Provided you clean out all the lines to and from the pump and injectors you should get away with it though.

I suggest you get at least a couple of decent in line filters for the future, ideally ones with bowls so you can see the sediment and run them in series. Maybe also consider an auto cutout so that if water's detected in the filter it kills the engine. I've had red diesel straight from the delivery truck with water in it. Once it gets in the system the big problem is the fuel that bypasses the injectors and is fed back to the tank contains water in fine droplets which take ages to settle out so they keep going round and round the system til they kill the pump. I'd also make sure the engine gets fuel from above the bottom of the tank and regularly drain the unusable fuel at the bottom to check for water.

Rgds

Andy R

[Colin Blackburn]

Thanks for the further advice. The whole system is being gradually overhauled to I will consider putting filters inline as I move things around and replace stuff. Any recommendations for filters?

Colin

[Graham Wilson]

Doesn't answer your question, but it reminds me of something....

Years ago, there was a patrol officer for either the AA or RAC who wrote a book about some of the amusing problems that he and other patrol officers had come across on their travels. The patrol officer was interviewed on radio. I think I heard the interview on LBC radio in London.

The patrol officer said that he was called to a petrol station to deal with a car where someone had accidentally filled up their petrol tank with diesel. The patrol officer told the driver that they would need to arrange with a garage to drain the tank.

The patrol officer drove off after several minutes - and just as he was doing so - there was a major explosion at the petrol station.

The motorist had pushed their car over to the car vacum cleaner. They purchased a token, removed the back seat in the car (it was an old car) to reveal the petrol tank and removed the inspection cover to the tank. They shoved the hose from the car vac into the tank and put in the token.

The petrol in the tank was ignited by the spark in the car vac's electric motor and most of the petrol station went up in smoke.

Graham