Injection Valves Specification Example for City Buses: Adjustable Type
Injection Valves Specification Example for City Buses: Adjustable Type
This is a worked specification for injection valves in a adjustable type programme. It is the document we would send a buyer who asks what exactly they are getting: the material, the dimensions that are actually controlled, the finish, and the checks that happen before anything is packed.
The adjustable type version exists because the duty cycle on city buses is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually a fitment that looked right on paper and failed on the bench.

Example specification
| Item | Injection Valves |
|---|---|
| Application | City Buses |
| Version | Adjustable Type |
| Base material | Natural Rubber |
| Controlled dimensions | 5 key dimensions, recorded per lot |
| Tolerance band | ±0.05 mm |
| Finish | zinc plated |
| MOQ | 2,000 pieces per specification |
| Sampling | 14 working days, 3 days per revision |
| Compliance | REACH |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Natural Rubber, in this example.
- List the dimensions that are actually controlled and the tolerance on each.
- Name the finish and what it has to survive.
- State the inspection level and who pays when a lot fails.

Processes involved
- shot blasting
- robot welding
- sintering
- rubber vulcanisation
- cold forging
- anodising
Where this example applies
Programmes that run adjustable type most often specify this build for city buses. Related applications include workshop replacements, city buses, trailer axles, long-haul trucks, boat trailers.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 2.5 sampling on the finished lot.
- Finish inspection under agreed lighting.
- Carton drop test on the first lot of a new packing specification.
Questions buyers ask
What happens if a lot fails inspection?
The lot is re-inspected against the golden sample, and replacement pieces ship on the next available booking at our cost.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the REACH-compliant build instead of a fresh interpretation.
How is packing specified?
Individual packing, inner box quantity and carton marking are confirmed at quotation stage so the cartons arrive ready for your warehouse.
How long does sampling take?
Samples leave the factory in 14 working days, and each revision round adds about 3 days once you have seen the first piece.
Ask for the current catalogue and the specification sheet for this line.



