"Camel" Liquid Ring Medical Vacuum
Medical Systems
3-4
3.6 Vacuum Check Valve
Vacuum check valves are designed and engineered for the unique problems of the vacuum field. Featuring
extremely low pressure drop, they open on less than 1/10” W.C. Special design permits a lightweight, stamped
stainless steel disc to open fully, providing full flow with minimum resistance. A non-scuffing disc mechanism has
free action at all times. Positive shut-off even at minimum flow is assured by unique elastomeric permanently
molded facing (Viton or Ethylene Propylene - EPEM, or Teflon) on a specially designed stainless steel disc.
Noiseless, ruggedly constructed vacuum valves have a high safety factor. Each valve is individually tested before
shipment over a range from 0 to 50 psi backpressure and must show zero leakage at all pressures. All internal trim
is stainless steel.
3.7 Emergency Shutdown / Alarms
The following conditions may arise during operation.
3.7.1 Motor Overload Shutdown
This will shut down the pump in question and will not re-start until the reset button on the starter inside the main
control cabinet is reset. See Section 5 for troubleshooting information.
3.7.2 Lag Unit Running Alarm
This alarm will activate if the last available vacuum pump comes on. In the case of a duplex system, it will activate
when the second pump turns on or the lag vacuum switch (VS-2) closes. In the case of a multiplex system, the lag
alarm will activate when the last available unit is required to come on. For example, in a quadruplex system, if all
four (4) H-O-A switches are set to “Auto”, then the lag alarm will trigger when the fourth unit comes on. If on the
same system, three (3) of the four (4) H-O-A switches are set to “Auto” and the other to “Off” or “Hand”, then the
lag alarm will activate when the third unit comes on. To silence the alarm, press the "Horn Silence" push button. In
the event the lag alarm is persistent, check to see if any leaks or valves are open downstream or reduce the system
load. To reset the Lag Alarm, push the "Lag Alarm Reset" pushbutton.
Please note that the lag alarm may be reset even if the lag pump is still running. This can happen due to the
minimum run timer not having expired, but the lag vacuum switch itself may be open.
