Posi-Trap Vacuum Trap
Single-stage vacuum pump inlet trap with sealed elements
The Posi-Trap is Mass-Vac’s single-stage vacuum pump inlet trap. Its filter elements are sealed at both the inlet and the exhaust ends, which stops gas bypassing the element: everything that comes down the line has to pass through the filter media.
Sizes and connections
The 4″ Posi-Trap takes one 4.5″ element and the 8″ takes four. Both come straight-through or right-angle, with hose terminations or NW flanges: NW25 or NW40 on the 4″, NW40 or NW50 on the 8″. The body is stainless steel with Buna-N O-ring seals.
| 4″ straight-through | 4″ right-angle | 8″ straight-through | 8″ right-angle | |
|---|---|---|---|---|
| Hose terminations | 330000 | 335000 | 340000 | 345000 |
| NW25 | 330025 | 335025 | – | – |
| NW40 | 330040 | 335040 | 340040 | 345040 |
| NW50 | – | – | 340050 | 345050 |
Choosing the element
- Stainless steel or copper gauze for condensable particles and oil vapour; stainless where corrosion is a concern.
- Molecular sieve to cut oil backstreaming from a mechanical pump and trap water vapour.
- Soda lime to neutralise acidic vapours.
- Activated charcoal for organic vapours.
- Polypropylene, 0.1 to 20 micron, for high volumes of solids and fine particles.
Sorbents for mercury, ammonia, hydrogen sulphide, chlorine and hydrogen peroxide vapours are on the filter elements page. Elements change quickly and the trap is easy to clean.
What we need for a quote
The part number if you’re replacing a Posi-Trap, or the pump, the line size and what you’re trapping if it’s a new one.
