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Jet A-1 contamination

Jet A-1 contamination

(OP)
Hi again!

I am researching the possibility of multi-product pipelines, and need to know how much diesel (gasoil) or gasoline (mogas) is alllowed to contaminate Jet A-1. From what I've read, it seems the limiting factor may in fact be the water in the diesel and gasoline, rather than the products themselves (water must be below 30ppm in Jet A-1). Can anyone provide some insight? Thanks!

Gareth

RE: Jet A-1 contamination

No. Absolutely not. Mixing and segregation between grades has nothing to do with water content. Water is a separate issue and it's amount must be carefully held below very specific limits. It is usually settled out and drained off whenever and wherever possible.

Separation between similar products, gasolines, or distilates is always maintained and relatively no mixing is allowed. Gasolines of different octanes that are mixed in between batches producing an interface mixture can be carefully injected into the lower quality fuel. Gasolines of 92 Octane can be injected into gasoline of 87 octane, but not vice versa. Ultra low sulfur diesel can be injected into Low sulfur Diesel. Jet can be injected into diesel. No gasoline can be injected into jet or diesel, or visa versa.

Initial segregation of fuels is normally accomplished by specific gravity. Gasolines are lower than 0.76 Kerosene between 0.76 to 0.82. Jet 0.82 to 0.85, Diesels can range from 0.85 to 0.96

Other limits can apply such as vapor pressures, viscosities, pour point temperatures, freeze temperatures and even color. Vapor pressures are different between summer and winter grade gasoline mixes in many countries. It may not be a good idea to mix those at all.

you must get smarter than the software you're using.

RE: Jet A-1 contamination

Other contamination limits, such as sulfur content, zinc may also apply. Some countries still allow leaded gasoline. There are multiple grades of aviation gasoline colored red, green, purple and vary from 86 octane to 145. Jet fuels; jet, jet A1, JP4, 5, 6, 7 and 8. These can have special antifreeze and anti-icing properties and flash point (flammability) suppressors.

There are numerous and extensive specific ASTM specs that can be applied in each case.

you must get smarter than the software you're using.

RE: Jet A-1 contamination

(OP)
Thanks so much BigInch - I thought there might be a bit of contamination allowed (since Jet A1 and Diesel have overlapping carbon chain lengths, I figured that only C16-C21 would be contaminants). Seems it is a lot more complicated than that!

Thanks for the info! You seems to always have the information that I need :)

RE: Jet A-1 contamination

I fully agree. It's been a while since I was involved in MP pipelines to that extent, but normally Jet A1 was treated as the god of fluids and NO mixing was permitted at all. Jet A1 undertakes a number of tests before it ever gets on an airplane and any contamination could take it off spec and then you have a BIG PROBLEM if you've got thousands of m3 of fluid you can't use taking up valuable space at or close to an airport.

There was sometimes mixing of gasoline into diesel, and jet a1 into diesel, but as refining limits have got tighter, the allowable percent mix of contamination has reduced over the years. Each shipper has different allowances but you're generally into fractions of a percent of the total parcel or tank volume.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

RE: Jet A-1 contamination

(OP)
I never said thanks for your feedback BigInch and LittleInch, so thanks :)

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