Fuel Auto Filter Specification Example for Municipal Fleets: Sealed Unit
Fuel Auto Filter Specification Example for Municipal Fleets: Sealed Unit
This is a worked specification for fuel auto filter in a sealed unit 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 sealed unit version exists because the duty cycle on municipal fleets 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 | Fuel Auto Filter |
|---|---|
| Application | Municipal Fleets |
| Version | Sealed Unit |
| Base material | Forged Aluminium |
| Controlled dimensions | 5 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | as machined |
| MOQ | 500 pieces per specification |
| Sampling | 10 working days, 3 days per revision |
| Compliance | SGS |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Forged Aluminium, 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
- CNC machining
- cold forging
- rubber vulcanisation
- surface grinding
- die casting
- electroplating
Where this example applies
Programmes that run sealed unit most often specify this build for municipal fleets. Related applications include camper conversions, emergency vehicles, rental motorcycles, construction equipment, workshop replacements.
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
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 10 working days, and each revision round adds about 3 days once you have seen the first piece.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 500 pieces per line.
What is the minimum order quantity?
The standard MOQ is 500 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
Send the specification you are working to and we will confirm what we can match, what we would change and why.



