Why doesn't an international oil pipeline not explode when you turn it off?

Question

Aren't these things not like 500 km long freight trains of fluid?

Answer 1

Who says they don't?

Yes, it is a problem shutting down the substainial flow then can amount to a lot of energy that has to be dissapated.  

Typically, the pumps are slowed down gradually letting the friction of the flow disipate the energy.

A central dispatcher orders the pumpstations to slow down until the flow is halted.

Particularly dangerous are down hill segments where static head pressure can sometimes exceed operating pressures.

I've heard, some of the "terrorist attacks" on Iraqi pipelines are called that to avoid admitting to operating errors which caused ruptures and/or explosions.

Answer 2

There would have to be a spark, explosion, or something else to set the fuel off.  Your car doesn't explode when you shut it off, nor does a tanker truck full of jet fuel filling up a plane.  Both of these are just scaled down versions of a pipeline.  Additionally, fuel and oil are not explosive, nor flammable in their pure state.  In fact, you can extinguish a match in jet fuel under the proper conditions.  The reason, unless there is a proper fuel/air mixture there can be no combustion, as combustion of a petrochemical requires oxygen.  After all, an explosion is just a chemical reaction with the ignition source (i.e. flame) acting as the energy source and catalyst for the chemical reaction.

Answer 3

because they don't