Tight-lining?

[camfink]

Im sure this is probably a pretty easy question for you guys. But what does it mean when somebody uses the phrase "tight-lining" in the piping industry?

Thanks,

 

[SNORGY]

I am thinking it might have to do with pulling a PVC or HDPE liner as a corrosion barrier into a steel carrier, with the space between the OD of the liner and the ID of the carrier pipe of such close tolerance that when pressurized or commissioned it actually becomes an interference fit.

Regards,

SNORGY.

 

[JLSeagull]

http://eng-tips.com/viewthread.cfm?qid=257493&page=1

I do instrumentation so my explanation could be completely bogus. See the Slack Line Flow thread in Petroleum Production. Let's pump crude through line NPS 36 from a valley over a 14,000 foot mountain range to the coast. The inertia of the crude flowing down the mountain can pull apart or flash with segment of non liquid full piping. This is a slack line. A tight line maintains control over the flow to maintain a liquid full pipe or tight line.

 

[rneill]

snorgy has it correct. You stretch the plastic liner out or squeeze it down so that it's diameter is reduced when pulled into a existing (or new) steel pipeline. Eventually the material relaxes and when it does you get a very tight interference fit with the steel casing. The steel casing provides the strength and the plastic liner the corrosion resistance.

Two excellent references (available freely online):

“Handbook of Polyethylene Pipe”

http://plasticpipe.org/publications/pe_handbook.html

“Tite Liner® Engineering and Construction Guide”

http://www.unitedpipeline.com/mm/files/Web Eng Guide.pdf