Rubber hose batch records: the questions buyers keep asking

Buyers start here because the tube and cover compounds decide oil, heat and ozone resistance. Your record should name the compound code, the mixing batch and the mill date for both tube and cover.

Hold the cure data too. Press or autoclave temperature, time and the operator on that run show whether the hose was cured as specified. If a compound batch is later found faulty, you need to list every length that used it within minutes.

Never rely on a supplier’s certificate alone. Keep the compound lot you actually weighed out, because bags from two deliveries often sit side by side at the mixer. Mixed up lots are hard to separate afterwards.

Reinforcement is the textile braid, spiral wire or steel cord that carries the pressure. Customers ask for the supplier lot, the spool number and the number of plies or spirals. A weak spool is the classic cause of a burst well below rating.

The mandrel matters for bore size and surface finish. Record the mandrel number and its diameter check, since a worn mandrel gives a rough bore and uneven wall. Link it all to the length number printed or stencilled on the hose.

Wrapped hose adds the fabric or tape lot. Cured hose adds the curing vessel and the wrap tension used. Write them all down.

Each tested length needs a proof pressure, a hold time and a recorded result of pass or fail. Add the gauge number and its calibration date, because an auditor will ask whether the gauge could be trusted. Add the tester’s name and the time.

Burst tests are done on samples, so record which length was sacrificed and what that result says about its neighbours. Be clear in the record about which standard the test followed. Buyers read that line first.

Hydrostatic testing fills the hose with water, applies the specified pressure and checks for leaks, swelling or length change. Record the measured change in length and the outside diameter before and after. Note any visible weeping at the crimp or cuff.

Add the final inspection sheet: inside diameter, wall thickness, length and marking check. Attach a photo of the stencil. Disputes often turn on whether the hose in the field was ever marked the way the buyer expects.

A buyer who finds a leaking cuff wants to know if the hose was tested wet or dry, and at what temperature the water stood. State it. Short answers close complaints quickly, and vague ones open a long email chain.

When a hose fails in the field, the buyer sends a length number or a photo of the marking. You should reach compound, reinforcement, mandrel, cure and test records from that one number without hunting through folders.

Test it on a past order this week. Pick one shipped length and stand over a stopwatch while someone gathers every record. Whatever slows them down is the gap to fix first.