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Industries · 04

PVC pipe

The highest-volume pipe category of all — weight, wall and diameter, none of them can drift.

Sealion's systems cover the extrusion process and quality control of plastic pipe: gravimetric control at the feed throat holds weight-per-metre, ultrasonic gauging watches wall and outer diameter, and end-of-line inspection stops what fails.

But PVC pipe is really two products on the extrusion line: ordinary PVC-U pipe, and PVC-O pipe, made by biaxially stretching a formed PVC-U pipe blank (GB/T 18998). Same material, but the gauging call on the two lines is not the same — they are treated separately below.

The exact configuration depends on your diameter, formulation and line cycle — an engineer will work that out against your actual line.

PVC-O pipe

The gauging call has to be made on site

PVC-O is made by stretching a formed PVC-U pipe both axially and radially. After orientation the wall is markedly thinner, and measuring and controlling that wall is the critical step of the process; ordinary ultrasonic in-line gauging cannot give a stable reading on the oriented layer, so the gauging package on a PVC-O line cannot simply be copied from ordinary pipe.

Everything upstream of the stretching is settled: gravimetric and dosing control hold the material used per metre. The wall-gauging step has to be confirmed on site against diameter, orientation ratio and melt temperature, with a sample trial first where needed — this is one thing we do not promise in general.

Tell an engineer about your line

Diameter, material, line cycle, the parameter you need held — with those, we can propose the right configuration.