Tray design is one of the first questions an engineer settles when sizing a PEV feeder, and it affects not only price but operating conditions, workplace safety requirements and compatibility with downstream equipment.
When an open tray is enough
An open tray is the base, more affordable design. It suits materials that are not toxic, not dust-explosive and where some release to the environment is not critical: crushed stone, sand, gravel, coarse ore on a plant site. An open design is easier to inspect — tray wear and leftover material are visible, and it's easier to clean during downtime.
When a covered tray (PEVU) is needed
The "U"-suffix design (PEVU) applies when at least one of these is true:
- the material creates dust that is a hazard to staff or forms an explosive dust-air mixture (flour, soda ash, fine fertilizer, coke breeze);
- the material is hygroscopic or must stay dry between the hopper and the next process step;
- the process needs a sealed joint to the next piece of equipment (a screw conveyor, elevator, enclosed belt);
- sanitary rules for the plant (food, chemical) do not allow an open transfer point.
See which industries most often need a covered tray in our notes on feeders for the chemical industry and grain handling and food processing.
Comparison by key criteria
| Criterion | Open tray | Covered tray (PEVU) |
|---|---|---|
| Dust containment | No | Yes, sealed housing |
| Weather/moisture protection | Limited | Full with a sealed joint |
| Inspection and maintenance | Quick visual check | Through inspection hatches |
| Typical use | Crushed stone, sand, ore outdoors | Flour, soda ash, fertilizer, food ingredients |
| Cost | Lower | 10–20% higher |
What this changes in price and lead time
A covered tray needs extra housing welding and, where required, seals at the joints — this raises both cost and lead time compared with an open design of the same model size. Check the exact difference for your model when placing a request.
Not sure which design your material needs? Describe your task via the request form and we'll suggest the right option.