Self-Priming High Pressure Washer Specification Example for City Buses: Sealed Unit
Self-Priming High Pressure Washer Specification Example for City Buses: Sealed Unit
This is a worked specification for self-priming high pressure washer 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 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 | Self-Priming High Pressure Washer |
|---|---|
| Application | City Buses |
| Version | Sealed Unit |
| Base material | High Density Foam |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | anodised |
| MOQ | 1,000 pieces per specification |
| Sampling | 14 working days, 5 days per revision |
| Compliance | ECE R90 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — High Density Foam, 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
- surface grinding
- sintering
- rubber vulcanisation
- laser cutting
- electroplating
- powder coating
Where this example applies
Programmes that run sealed unit most often specify this build for city buses. Related applications include camper conversions, export programmes, fleet maintenance, rental motorcycles, scooter fleets.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 1.5 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
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 is the minimum order quantity?
The standard MOQ is 1000 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
What testing is included?
Standard lots ship with dimensional and hardness reports. ECE R90 documentation is issued with the shipment when your market requires it.
How long does sampling take?
Samples leave the factory in 14 working days, and each revision round adds about 5 days once you have seen the first piece.
Send the specification you are working to and we will confirm what we can match, what we would change and why.



