PE Liner Pull Force at Expansion Loop / Curve Portions?

[ram0608]

We use polyethylene (HDPE-100 Grade)pipes as internal corrossion protection for carbon steel pipes in water injection and crude oil applications. I would like to know what will be pull force at expansion loops / curves while pulling PE Liner from one end to other end. Is Capstan Effect formula can be used for such type of pulling where theta value is 90 Degree (Pipe line bend angle)? Seeking experts openion in this regard? Thanks in advance - RAM

 

[bimr]

You are not going to be able to pull HDPE pipe through expansion loops.

Bends are usually so long in radius as to be within the flexural bending capability HDPE pipe which can be cold bent to 25 times its nominal OD (example: for a 12” SDR 11 PE pipe, the radius of curvature could be from infinity down to the minimum of 25 feet, i.e., a 50-foot diameter circle).

Here is a reference:

http://plasticpipe.org/pdf/chapter12.pdf