Phase Change Cooling System Specification Example for Municipal Fleets: Two-Piece Construction
Phase Change Cooling System Specification Example for Municipal Fleets: Two-Piece Construction
This is a worked specification for phase change cooling system in a two-piece construction 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 two-piece construction 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 warranty claims traced back to a single lot.

Example specification
| Item | Phase Change Cooling System |
|---|---|
| Application | Municipal Fleets |
| Version | Two-Piece Construction |
| Base material | Nylon 66 |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | zinc plated |
| MOQ | 500 pieces per specification |
| Sampling | 7 working days, 5 days per revision |
| Compliance | DOT |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Nylon 66, 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
- rubber vulcanisation
- powder coating
- injection moulding
- gravity casting
- die casting
- laser cutting
Where this example applies
Programmes that run two-piece construction most often specify this build for municipal fleets. Related applications include off-road bikes, three-wheelers, trailer axles, emergency vehicles, scooter fleets.
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 DOT-compliant build instead of a fresh interpretation.
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.
What testing is included?
Standard lots ship with dimensional and hardness reports. DOT documentation is issued with the shipment when your market requires it.
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.
Ask for the current catalogue and the specification sheet for this line.



