what is the material of pipeline in ngv?

Question

for academic purposes. thanks a lot

Answer 1

Like anything that burns, methane and the minority ethane of the natural gas don't oxidize the inside of the pipes so the 1000 psi pressure is the primary factor for a suitable pipeline material.

Cast iron is the cheapest and used for long spanning. But it cannot be welded and suffers graphitization, so steel may be preferable. Iron and steel pipes suffer external corrosion and hence must be coated with a damage resistant ductile cathodic protection layer: something like an aramid polyester resin.

An all-plastic pipe may be used on stepped-down pressure sections, but it may suffer electrostatic pinhole leak over time.

For lighter vehicle weight smaller-diameter reinforced aluminum core tanks are also used even at near the 3600 psi full-charged pressure.