Diesel Engine Fuel System Specification Example for City Buses: Fixed Type
Diesel Engine Fuel System Specification Example for City Buses: Fixed Type
This is a worked specification for diesel engine fuel system in a fixed 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 fixed 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 documentation that arrived after the container shipped.
Example specification
| Item | Diesel Engine Fuel System |
|---|---|
| Application | City Buses |
| Version | Fixed Type |
| Base material | Ceramic Composite |
| Controlled dimensions | 6 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | anodised |
| MOQ | 500 pieces per specification |
| Sampling | 7 working days, 3 days per revision |
| Compliance | SAE J431 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Ceramic Composite, 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
- powder coating
- rubber vulcanisation
- cold forging
- ultrasonic cleaning
- robot welding
- CNC machining
Where this example applies
Programmes that run fixed type most often specify this build for city buses. Related applications include delivery vans, three-wheelers, long-haul trucks, assembly programmes, passenger cars.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 4.0 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
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the SAE J431-compliant build instead of a fresh interpretation.
Can you match an existing sample?
Send a sample and we will reverse-engineer the specification, then produce a counter sample for approval before any bulk starts.
What testing is included?
Standard lots ship with dimensional and hardness reports. SAE J431 documentation is issued with the shipment when your market requires it.
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.
Send the part number, the annual volume and the target market, and we will come back with a specification and a sampling plan.
