Lifting HDPE and PVC Flexible Pipe Safely

HDPE and PVC pipe are light compared to steel or concrete, but that does not make them easy to lift. Long plastic pipe bends under its own weight, swings easily and scratches more readily than steel. Vacuum lifting equipment handles it well, provided the lift is set up for a load that flexes. This article explains what changes when the pipe is plastic.

Why plastic pipe behaves differently

Steel pipe is stiff. Lift it at its centre and it stays straight, and the main concern is protecting its coating, as covered in lifting coated steel pipe. HDPE and PVC are far more flexible, so a long length lifted at one point droops at both ends. The longer the pipe, the more it sags, and the ends can drag on the ground, hit obstacles or swing as the carrier moves.

Plastic pipe is also softer on the outside. Scratches and gouges from contact with the ground, rigging or other pipes weaken the wall, and on pressure pipe many specifications limit how deep such damage may be before a length has to be rejected. And PVC becomes more brittle in cold weather, so impacts that would do nothing in summer can crack it in winter.

Where slings and single-point lifts fall short

The conventional approach is one or two slings around the pipe body. On a long plastic pipe that gives two problems. First, the pipe hangs in an arc between and beyond the slings, so the lift is never fully under control. Second, slings can slip on the smooth plastic surface, and dragging them into place or pulling them out from under a pipe in a trench is exactly the kind of contact that leaves scratches.

Lifting by the ends is not an option for long flexible pipe at all: the middle simply sags.

How vacuum lifting handles flexible pipe

A vacuum lifter holds the pipe from above with suction pads, so nothing goes around or under it. For long plastic pipe the key is to use several pads spread along the length. Vlentec's flexible pipe lifting attachment is built for this.

Pads that follow the bend

The attachment places the suction pads on an extension beam. With the Flex-Connect System, the pads can move with the pipe's bend and shift in any direction. A flexible pipe never hangs perfectly straight, and pads that follow its curve keep their seal where rigid pads would lift off at the edges.

Seals for welds and joints

HDPE is often joined by butt fusion, which leaves a weld bead on the outside, and pipe surfaces are not always perfectly smooth. The attachment uses thick seals that maintain the vacuum over slightly rough surfaces, welds and pipe joints.

Guided positioning

A guide wheel kit helps position the pads on the pipe, so the operator can line up the lift quickly without anyone guiding the pads by hand.

Water and sewage work

HDPE, PE and PVC are standard materials for drinking water mains and parts of sewer and drainage networks. Much of that work happens in trenches in built-up areas, where space is tight and people should stay out of the trench while pipe is lowered in. Lifting from above with a vacuum lifter keeps the crew clear, and the same carrier can also handle the heavier concrete and ductile iron components on the same project. More on these applications is on the water and sewage page.

In urban areas, emissions and noise are often restricted. The electric ED125N runs with zero emissions in operation and a silent pump, which suits work close to homes and offices.

Capacity

Plastic pipe is light per metre, but long lengths and multiple-pipe lifts still add up. The flexible pipe lifting attachment has a standard lifting capacity of 7,500 kg. For heavier or unusual loads, Vlentec engineers custom made solutions.

Frequently asked questions