Nine Checks Between Raw Material and Finished Hose

Time：2026-10-17 17:13:35

Good compound is necessary and not sufficient. A hose made from the right PVC powder, on a badly controlled line, still leaves the factory out of tolerance — and the buyer finds out at the coupling.

The reasoning behind the process

Our position is simple: in addition to ensuring the quality of raw materials, final product quality can only be guaranteed if the production process itself is strictly controlled. Raw material checks catch a bad batch before it enters the extruder. Process checks catch a drifting line before it produces a kilometre of hose that has to be scrapped.

Both are needed because they fail differently. A raw material problem tends to be sudden and visible. A process problem is gradual and invisible until the finished hose is measured.

The nine checks, and what each one is for

Check	What it catches	What happens if it is skipped
Inner diameter	Bore size against the nominal size	Fittings do not seat; flow rate falls short
Wall thickness	Wall consistency around the circumference	Weak side in the wall; early failure at pressure
Outer diameter	Outside size and ovality	Clamps and reels do not fit; stacking problems
Hardness	Shore A of the finished compound	Hose too stiff to bend, or too soft to hold shape
Tensile strength	How much the material stretches before it breaks	Wall splits instead of stretching under load
Peel strength	Bond between reinforcement and the PVC layer	Delamination: the layer separates before the hose bursts
Burst pressure	Peak pressure at rupture	The rated number is a guess
Permanent pressure	Behaviour under sustained pressure	Hose passes the burst test and creeps in service
UV resistance	Ageing under simulated sunlight	Surface cracks after one or two seasons outdoors

Where the material comes from

The compound is only as good as its inputs, so the supply side is part of the same argument. Our main raw materials come from Qilu Petrochemical, a chemical company under Sinopec, as well as Beiyuan Chemical, Wanhua Chemical and BASF. Our production technology is European in origin, with part of it coming from Italy, Germany and Spain.

Material inspection is documented separately from process inspection: PVC powder and plasticiser are checked on arrival, and PU material from BASF is held to its own incoming record. A process test cannot recover a compound that was wrong at the gate.

What a buyer can reasonably ask for

Which of the nine checks are routine and which are sampling-based. Not every test runs on every metre.
Where the records live, and whether they are tied to a batch number that appears on the packing list.
What the acceptance limits are for the dimensions, not just that the check exists.
What happens to a failed lot. The answer tells you more about a factory than the certificate does.

Why we publish the list at all

Most catalogues show a hose and a pressure rating. The list of checks is less photogenic, but it is the part a technical buyer can actually audit. If a supplier cannot name the tests, the rating on the front of the catalogue is not backed by anything you can verify.

Ask for our QC process sheet — the nine checks, the acceptance limits and the batch record format.