Diesel Fuel questions

[FF]

"So the question I have after reading all these US centric points is, why does the US sell such poor quality fuel?"

In the USA most of the fuel is delivered over long distances by pipe lines. The pipes carry different fuels , kept apart by a plug called a pig.

The fuels are delivered to locations that are supposed to filter the fuel and fill delivery trucks with their product.

Some distribution points do a better job than others , same as gas station or marina , some keep their filters clean , and insert the proper additives ,some have very transient customers , so don't bother.

 

[ronobrien]

Diesel does last quite a while with no problems. Winter storage is not an issue. One thing I will caution about is biocide additives. They are a good idea to prevent algae, but use ONLY the amount prescribed for the fuel quantity being treated. The thought that if X is good, then X+ must be better could not be further from the truth. An excess (not specific) of additive creates a crystalline build up in the fuel which is as bad as the algae. A one time variation from the prescribed amount is not a big deal, but if that practice continues, the ratios increase with every fill up. This leads to the longer term problem. So pay attention to the ratios. If not you may wind up removing the tank for cleaning, or at least have a messy job on board. An upgrade to a full time polishing system is rather expensive (relative) but helps greatly to protect the fuel, tanks, & system.

 

[NCheaven]

Biobor JF: When I first was investigating Biobor JF, I googled it, and came up with a paper on bio-diesel problems for emergency generators at a state owned facility - Washington State or Oregon - I forget which. Anyway, they were having problems with Bio-Diesel going bad - algae, and wanted to continue using bio-diesel for ecological reasons, but had learned that bio-diesel goes bad faster that petro-diesel. The did some studies using Biobor JF, and found it to help reduce the algae growth in storage tanks in a system to be used infrequently - emergency generation. Very interesting study, but not so interesting that I every went back to re-read it..... But, it and other sources contributed to my choice to use Biobor JF several times during the year to keep the "bugs" at bay.

Curiosity got to me....googled Biobor JF, found a very old Fed Aviation study on Biobor JF effectiveness at various concentrations in preventing jet fuel microorganism growth, and charts show what is needed to be effective. Study was done following B-48s having engine problems due to fuel micro-organisms. (And you think WE have problems if our fuel clogs up....!) I also found a 2015 Practical Sailor study on biocides and lubricity additives - B-JF was top for biocides, but lubricity comments were not encouraging - something else recommended for that, and PS recommended using B-JF and another additive together to address both issues. Lots of info, independent tests are out there if you want to take the time to read those. Biobor JF and Valve-Tect fuel is the combination that I prefer, although Valve-Tect seems to claim that Valve-Tect has adequate microorganism fighters by itself. Entertaining reading for long, gray sky days in the dead of winter.....

 

[JimW]

As long as you have something you are confident in us it, diesel is a bigger challenge for us Trawler Types as we typically don’t burn through a high volume of fuel and turn it over frequently . . . CLASSEA uses Ultra Guard and it works great for her . . .

 

[High Wire]

I worked in a nuke plant 25yrs ago that had four 4000kW diesel gens as emergency backup. I was part of the team in charge of keeping those old beasts alive (Nordberg 16V, 13" bore, 16" stroke). On site we kept enough fuel for 7 days of operation. Something like 150-200,000 gallons of diesel. These things did not run very often, so the fuel just sat.

We had a chemist that was in charge of testing the fuel. I was not involved in that. I don't recall ever seeing the railcars coming in to drain the tanks and reload with new fuel. Or whether they used some sort of special long life fuel. Just know the chemist said the fuel in the tank was good. And she was cute!!!

Curious how hospitals and nuke plants handle this now. Both store a lot of fuel and don't go through much. Did a little little sniffing on the net and kept finding that "six months and it starts to degrade" thing. Sure there might be some degradation then, but I have seen diesel 7-10yrs old do just fine.

Anyone with recent experience in hospitals or nuke plants? They don't mess around with the reliability of their stored fuel, and I don't think they exchange it often, either.

We too had 4- 4430 Kw Colt Pielstik diesel generators. Each gen had two 50,000 gal tanks. Total 300,000+ gals minimum just for the diesels. Each tank was sampled monthly and there was a staggered tank inspection interval of 10 years. When it was time to inspect, the tank was sampled then distributed to the other tanks. The fuel truck when it arrived was also sampled. I forget the standard number for the tests but each sample was always good. The tanks had designed bottom section to capture water and there was also a quarterly surveillance requirement to drain off any accumulated water. In over 20 years we only had a delivery of one tanker that did not meet spec and that was our more conservative admin limit. Rejected fuel went to the house heating boiler Million Gallon Tank.

 

[Ski in NC]

We too had 4- 4430 Kw Colt Pielstik diesel generators. Each gen had two 50,000 gal tanks. Total 300,000+ gals minimum just for the diesels. Each tank was sampled monthly and there was a staggered tank inspection interval of 10 years. When it was time to inspect, the tank was sampled then distributed to the other tanks. The fuel truck when it arrived was also sampled. I forget the standard number for the tests but each sample was always good. The tanks had designed bottom section to capture water and there was also a quarterly surveillance requirement to drain off any accumulated water. In over 20 years we only had a delivery of one tanker that did not meet spec and that was our more conservative admin limit. Rejected fuel went to the house heating boiler Million Gallon Tank.

That seems to mirror my experience, even though I was not involved in the chemistry side.

Periodic sampling, good tank water draining features, and the fuel could be many years old and still be ok.

I also worked earlier on nuke subs, which also had a diesel backup gen. Due to buoyancy requirements, as diesel was used from the tanks, water was allowed to enter the bottom of the tank. This minimized trim effects due to varying fuel quantities. Much bigger deal on the old diesel boats, they really went through some fuel.

But the bottom line from that is that water does not seem to mess up the fuel. Just need to separate the two well before the engines. And the subs certainly had a good system for that.

I have never sent a fuel sample to the Caterpillar fluids lab I use, but I know they do more than just sample lube oil. So if you have several year old fuel, that sample might be a whole lot cheaper that any other option like draining the tank!!

 

[C lectric]

I will second Ski's suggestion of sending a sample to a lab.
I too use the CAT SOS tests.