Short for mechanical pump, the name US lab and fab techs give the oil-sealed rotary vane pump that roughs and backs a system. The term separates it from the hi-vac pump (turbo, cryo or diffusion pump) further up the stack. Mech pump care is a routine chore: check oil level and colour in the sight glass, run gas ballast after wet loads and change the oil on a schedule.
Mech pump's gurgling, it's pulling on a leak somewhere, go check the foreline clamps.
A rotary vane pump that gurgles or blows oil mist out of the exhaust is moving far more gas than it should, so look for an open valve or a gross leak before blaming the pump.
Also heard as
- mechanical pump
Related terms
Rotary vane pump
Oil-sealed positive displacement pump in which sliding vanes sweep gas around an off-centre rotor.
Roughing pump
Pump that takes a chamber from atmosphere down to the pressure where the high vacuum pump can take over.
Backing pump
Pump that keeps the exhaust of a turbo, diffusion or Roots pump below its maximum allowed pressure.
Stack
Shop name for the whole column of high vacuum pump, valves, trap and backing line that pumps a chamber.