Applications
Lifting Coated Steel Pipe Without Surface Damage
A pipe coating protects steel against corrosion for decades, but only if it reaches the trench intact. Every lift between the coating plant and the final weld is a chance to scratch, dent or crack it. Vacuum lifting reduces that risk at the source: the lifter holds the pipe on soft rubber seals, without hooks, slings or clamping force on the coated surface.
The short answer
Coating damage comes from contact points, and vacuum removes them
Hooks, slings and clamps all put force on a small area of the pipe or its coating. A vacuum lifter holds the pipe over the full area of its pad, with only the rubber seal touching the coating and no clamping force. That makes it well suited to smooth factory coatings such as FBE and three-layer polyethylene or polypropylene, and to concrete weight-coated pipe within the right capacity class.
Why coating damage matters
A damaged coating is not a cosmetic problem. A scratch or crack that reaches the steel, known as a holiday, becomes a starting point for corrosion once the pipe is buried or submerged. On most pipeline projects the coating is inspected before lowering in, and every defect found has to be repaired. That costs time on the spread, and a defect that is missed costs far more later.
The cheapest coating repair is the one that is never needed. That is why the handling method between the coating plant, the stockyard and the right-of-way matters as much as the coating itself.
Where conventional handling damages coating
End hooks
Hooks lift the pipe by its ends. They put the full weight on a small contact area at the bevel or the inside of the pipe, and they can damage internal linings and the cutback area that has to be welded later.
Slings and belts
Slings wrap around the pipe body. Even soft slings concentrate the weight along a narrow band, and they can slip or drag over the coating while being attached or removed. Steel slings and chains are worse, which is why they are generally kept away from coated pipe altogether. The wider comparison is covered in vacuum lifting vs slings and hooks.
Clamps
Mechanical clamps grip the pipe by squeezing it. That clamping force acts directly on the coating at the contact points, and on thinner or softer coatings it can leave marks.
How vacuum lifting protects the coating
A vacuum lifter places a curved pad on top of the pipe and removes the air between pad and coating. Atmospheric pressure then holds the pipe against the pad. Three things follow from that:
- The weight is spread over the whole pad area instead of a few contact points, so there is no point loading on the coating.
- There is no clamping force. The pipe is held, not squeezed.
- Only the soft rubber seal touches the coating. Nothing is wrapped around the pipe or hooked into its ends, so the bevels and any internal lining stay untouched.
The pad also holds the pipe steady, which limits swinging and contact with other pipes during the lift. For the underlying principle, see how vacuum lifting works.
Common coatings and how they handle
| Coating | Surface | Vacuum handling |
|---|---|---|
| Fusion bonded epoxy (FBE) | Thin, hard and smooth | Seals well. Avoiding point loads and abrasion is the main concern with this thin coating. |
| Three-layer PE or PP (3LPE, 3LPP) | Thicker, smooth outer layer | Seals well. Protecting the outer layer from dents and scoring is the priority. |
| Concrete weight coating | Heavy concrete layer over the corrosion coating | Possible on a sound, sufficiently smooth surface. The weight is much higher, so capacity is the deciding factor. |
| Spirally welded pipe, coated | Raised spiral weld under the coating | Suitable. The pad seals over the weld profile. |
For pipe coaters, handling freshly coated pipe out of the line is one of the main applications. More on that is on the page for pipe coaters.
Single pipes and multiple pipes
On the right-of-way, pipe is usually lifted one length at a time for stringing and lowering in. In coating plants and stockyards, where many lengths move between racks, lifting more than one pipe per cycle saves time. For that work Vlentec offers a multiple pipe lifting attachment, which handles several coated pipes in one lift with the same pad principle.
Weight goes up with coating
Coating adds weight, and a concrete weight coating adds a lot. A pipe that is comfortably within the 12,500 kg class bare can move into a higher class once it is concrete coated. Always size the lifter on the coated weight of the heaviest pipe you handle, at the reach you will work at. For the heaviest concrete-coated pipe, used on many oil and gas pipeline projects, that means the 32,000 kg class.
Keep the contact area clean
The seal protects the coating, but only if nothing hard sits between seal and coating. Grit, gravel or hardened dirt under the pad can both leak air and press into the coating. On a dusty or muddy right-of-way, a quick wipe of the lifting area before picking is part of good practice.
Frequently asked questions
Can a vacuum lifter handle freshly coated pipe?
Yes. Handling coated pipe straight from the coating line is a common application for pipe coaters. The coating must have cured enough to be handled, as with any other lifting method.
Does the rubber seal leave marks on the coating?
The seal is soft and there is no clamping force, so the contact is far gentler than with hooks, slings or clamps. A clean contact area matters: grit trapped under the seal is the main cause of marks.
Can concrete weight-coated pipe be lifted with vacuum?
Yes, on a sound and sufficiently smooth concrete surface. Because concrete coating adds a lot of weight, choose the capacity class on the coated weight. The heaviest pipe calls for the 32,000 kg class.
Is spirally welded pipe a problem?
No. Vacuum lifting works on spirally welded pipe. The pad seals over the weld profile.
Would you like to learn more about vacuum lifting technology?
Brendan Boelema, CEO & Owner
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