"David Lesher" wrote in message ...

We never used dye. The operator has a stainless sink that drains into the
slop tank. In it is a large graduated cylinder. The faucet samples the
incoming line and pours into the cylinder; it oveflows into the sink. He
has an approprite hydrometer bobbing in it.

He "makes the cut" by observing the color change and the specific
gravity. He punches the [explosion-proof, of course!] pushbutton on the
valve panel when it's time.

He may cut early. middle or late; it depends on the two products. The
schedulers try to make adjacent 'tenders' friendly. Say $2 Fuel Oil
followed by Jet-A. That would be an late cut; he waits until he's sure
it's all Jet-A then he swings the valve. A few barrels of Jet-A aka
Kerosene will not hurt 100,000 bbls of #2FO.

If an unfriendly cut, say gas to Jet-A; he'll cut early to the slop
tank, and then ~~5-10 min later to Jet-A.

The slop tank is eventually emptied by being slowly injected into
a Kero/FO incoming stream; the tank is later tested to be sure its
flashpoint remains above 110F.


Specialty fuels may not travel the pipeline, but be shipped some
distances by tanker truck, or barge.

Fuels such as.... AvGas.
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Thanks Dave! Can 87 octane be mixed with ~93 octane to arrive at 90 octane? Seems like a lot of black magic (no pun
intended) in the oil business...