On Thu, 28 Jun 2007 00:15:25 +0000 (UTC), David Lesher
wrote:

"Morgans" writes:


The pipeline people send many various grades of gas, all through the same
pipeline. They may send 95 octane straight gas for 4 hours, then switch to
82 octane for 2 hours, and so on, with the right storage facilities along
the way intercepting it, and putting it into separate tanks. I believe how
they know how to switch over, is to first know how long the switch in types
to get to them, then the senders put a dye package into the fuel to alert
the storage and distribution people that it is time to switch some valves,
and send the next fuel into a different tank.

Pretty close.

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.

Over 20 years ago I had the chance to tour the pumping and fuel
distribution control facility at a refinery. *Everything* was
controlled from that room. They measured flow rates
Vs time and claimed they could control the flow to the remote storage
facilities hundreds of miles away within several gallons. the system
was automated. The operator told it how many gallons of what to go
where. Different mixes and fuels were sent through the same pipeline
with no one on the other end to either make the switch or to monitor
it.