Pipe re-rounding tools apply how much hydraulic pressure before pulling an HDPE sewer slip-liner?
Short answer
Pipe re-rounding tools apply between 3,000 and 5,000 PSI of hydraulic system pressure to generate 10 to 40 tons of radial expansion force before pulling a sewer slip-liner. Setting the pressure relief valve between 3,000 and 3,500 PSI reliably restores circular clearance without fracturing brittle host pipe walls. Maintaining this pressure for 60 to 120 seconds stabilizes surrounding soil so the new pipe inserts smoothly.
Hydraulic pipe re-rounding equipment operates at hydraulic system pressures between 3,000 and 5,000 PSI to generate 10 to 40 tons of radial expansion force before pulling a high-density polyethylene sewer slip-liner.
Ovality and localized collapse in aging clay, ductile iron, or concrete sewer pipes routinely reduce internal clearance below allowable tolerances for continuous high-density polyethylene (HDPE) slip-lining. Under ASTM F585 trenchless rehabilitation practices, host pipe cross-sections require uniform clearance within 2% to 5% of nominal bore diameter to prevent liner binding and wall gouging during the insertion pull.
If you only do one thing: Calibrate your hydraulic power unit pressure relief valve between 3,000 and 3,500 pounds per square inch (PSI) to reshape deformed sections without fracturing brittle host pipe walls.
- Host pipe survey: Run a multi-sensor closed-circuit television (CCTV) or laser profiling crawler through the lateral or main to map points where host pipe ovality exceeds 5% deformation.
- Tool configuration: Position a segmented hydraulic re-rounding expander sized 0.50 to 1.00 inch smaller than nominal host pipe inside diameter (ID) at the insertion pit.
- Hydraulic loading: Energize the hydraulic pump to supply 3,000 to 5,000 PSI fluid pressure, driving the internal wedge assembly to deliver 10 to 30 tons of radial thrust against deformed pipe walls.
- Dwell time: Maintain continuous expansion pressure for 60 to 120 seconds per segment to push back surrounding consolidated soil and stabilize the restored circular profile.
- Clearance proofing: Pull a rigid sizing mandrel matched to 105% of the outside diameter (OD) of the selected standard dimension ratio (SDR) 17 or SDR 11 HDPE liner through the entire run.
- Liner insertion: Hook the fused HDPE pipe string to a continuous-pull hydraulic winch running between 10,000 and 30,000 pounds of line pull, using a calibrated load-cell swivel to monitor drag.
- Watch out for: Exceeding 5,000 PSI hydraulic circuit pressure on vitrified clay or unreinforced concrete host pipes, which causes sudden wall shatter and ground voids instead of controlled radial expansion.
- Watch out for: Skipping the pre-pull proofing mandrel check, which risks wedging the HDPE slip-liner midpoint against uncorrected offset joints or sharp aggregate intrusions.
- Watch out for: Pulling SDR 17 or SDR 21 HDPE strings past 50% of the pipe material tensile yield limit when overcoming un-rounded host pipe friction.
Run a preliminary CCTV laser profile across the sewer run; if pipe ovality exceeds 8%, stage a 4,000-PSI hydraulic expander and a matching proof mandrel before fusing the HDPE string.