Welch Vacuum 2546 WOB-L Pinston Pump - Manual (Page 6)

6
2.50 INTAKE AND DISCHARGE PROVISIONS
2.51 The Two regulators and two gauges make it easy to meet your vacuum and pressure
requirements. The vacuum regulator and vacuum dial gauge is attached to the intake port.
The vacuum regulator allows the vacuum level to be set between roughly atmospheric
pressure and the maximum vacuum allowed for the pump model. A moisture trap keeps water
from accidentally being drawn into the unit. The pressure regulator and pressure dial gauges
are attached to the discharge port. The pressure regulator allows discharge pressure to be set
between atmospheric and the maximum possible for the pump model. Discharge air is fi ltered
and noise is muffl ed with a fi lter.
PROPERLY IDENTIFY THE INTAKE AND DISCHARGE OF THE PUMP
Intake Discharge
Pressure/Vacuum Pump
2.60 VACUUM CONNECTIONS
All pressure/vacuum pumps come with intake and discharge hose barbs which accept 1/4”
ID rubber pressure/vacuum hose. Hose clamps should be used to hold the hose in place.
Since all three models operate in the viscous fl ow regime, the small diameter of the hose will
generate minimal conductance loss. For best results, Welch recommends the length of the
tubing between the pump and the chamber be kept as small as possible.
2.70 VACUUM AND PRESSURE GAUGES
All models of pressure/vacuum pumps come with dial gauges mounted on the regulator
assemblies. The vacuum gauge gives negative pressure - that is pressure below atmospheric.
The reference point for the vacuum gauge is atmospheric pressure. The pressure gauge
gives pressure above atmospheric. The reference point for the pressure gauge is atmospheric
pressure. Please keep in mind that atmospheric pressure tends to vary from day to day. As a
result of this variability, the dial vacuum gauge will indicate slightly different maximum vacuum
readings from day to day.
Warning
Never Block The Discharge Port. If the exhaust is blocked, pressure
will build- up in the pump above its rated operating pressure. Be sure
to call Welch technical service prior to start-up at (847) 676-8800
if you have any questions.