Safe Pulling Strength for HDPE Pipe
Estimated Safe Pull Force, lbs
|Size||Nominal OD||SDR 9||SDR 11||SDR 13.5|
12 hour Pull IPS Size
The above table represents safe pull strength under perfect conditions. Consideration should be given to variables such as type of soil, ground conditions, length of run and operator experience.
Regardless of the installation method, mechanical stress is of great concern during conduit placement. Exceeding the maximum allowable pulling tension or the minimum allowable bending radii can damage conduit. Consult the conduit supplier for allowable pulling tensions.
During conduit pulling placement, attention should be given to the number of sweeps, bends or offsets and their distribution over the pull. Tail loading is the tension in the cable caused by the mass of the conduit on the reel and reel brakes. Tail loading is controlled by two methods. Using minimal braking during the pay-off of the conduit from the reel at times can minimize tension; no braking is preferred. Rotating the reel in the direction of pay-off can also minimize tail loading. Breakaway swivels should be placed on the conduit to ensure that the maximum allowable tension for that specific conduit type is not exceeded. The swivel is placed between the winch line and pulling grip. A breakaway swivel is required for each conduit.