See the below linked files for information on the vacuum pump used with 6270A, 7250, 7252, 3990, PPC3 and PPC4 pressure controllers to control pressures below and atmosphere (e.g. negative gauge mode). This vacuum pump is connected to the EXHAUST port of these controllers. A different vacuum pump is used when you need to connect a vacuum pump to the REFERENCE port of 7250 or 7252 controllers.
Fluke Calibration Part Number: 3584473
Description: VACUUM PUMP PACKAGE,110V
Fluke Calibration Part Number: 3584486
Description: VACUUM PUMP PACKAGE,220V
The VA-PPC/MPC OEM part number is DV-85N but if the pump is not purchased from Fluke Calibration the pump does not include the automatic solenoid valve.
The automatic solenoid valve vents the vacuum pump inlet to atmosphere when the vacuum pump is off and provides two benefits:
1. It's safe to use the pressure controller with the vacuum pump off. Without this valve, using the controller with the vacuum pump off would put positive pressure (from the controller's EXHAUST) to the vacuum pump and potentially damage the controller and the vacuum pump.
2. No vacuum remains in the controller's EXHAUST port that might pull oil from the vacuum pump into the EXHAUST port of the controller. This would contaminate the pressure controller and lead to a costly repair.
Some users like to add an exhaust filter to catch any oil vapor coming from the exhaust at the end of the handle. The exhaust threads on the end of handle are 1/2 inch NPT-M as of 2009, or 3/8 inch NPT-M prior to 2009. A NPT elbow would be used with most exhaust filters to connect them to the exhaust. NPT elbows are typically available at your local hardware store and could be any material that is compatible with vacuum pump oil. See the attached files for a couple of options for exhaust filters. Note that Fluke Calibration does not sell exhaust filters for these vacuum pumps.
Here is an exhaust filter that is sold by the pump manufacturer,
There are other inlet and outlet traps and filters available (but not sold by Fluke Calibration). Do an internet search for "Oerlikon RST" or see this link,
Vacuum pump with exhaust filter with NPT threads.