1 reply to this topic

[go-fish]

Hi,

The generally accepted maximum velocicty to prevent static electricity (important for hydrocarbons) is 15ft/sec or 4.6 m/s.

My question is when there is a significant slope along with vertical drop in a long(7-8 kms) pipeline, does it effect the line sizing or I can simply select my line size using Flow rate = Pipe inside area X Velocity.

Thanks

[ankur2061]

Hi,

The generally accepted maximum velocicty to prevent static electricity (important for hydrocarbons) is 15ft/sec or 4.6 m/s.

My question is when there is a significant slope along with vertical drop in a long(7-8 kms) pipeline, does it effect the line sizing or I can simply select my line size using Flow rate = Pipe inside area X Velocity.

Thanks

go-fish,

Most commercial hydrocarbons handled on large volume basis through pipelines and road/rail tank cars such as ATF, Kerosene, MoGas contain anti-static additives in order to increase their conductivity thereby making their handling and transportation safe. If anti-static additives are present and the liquid is no longer classified as a 'static accumulating liquid' then I don't see the reason for restriction of velocity due to of static charge. The more applicable criteria for restricting velocity would be the erosional velocity.

However for liquid pipelines with continuous operation, as a general rule, velocities above 4 m/s should be avoided. An important criteria for pipelines transporting liquids is surge and higher pipeline velocities tend to magnify the issue of surge.

Hope this helps.

Regards,
Ankur.