For safety and trouble-free operation, public works operators should:
The vacuum test
- Drain the pump casing completely to prevent freezing.
- If complete draining is not possible, pour a small amount of anti-freeze into the casing and rotate the pump shaft to mix.
- Seal the suction and discharge ports to prevent debris from entering.
- For oil-lubricated seals, drain the oil from the seal cavity and refill with 30-weight nondetergent motor oil.
- For water-cooled seals, pour ½ pint of lubricating oil through the discharge opening and turn the engine over to prevent excessive corrosion while keeping the mechanical seal lubricated.
After each job, run a simple vacuum test to determine the unit's pumping and priming capabilities. It only takes a few seconds.
Fill the pump case with water and apply a small amount of grease to the rubber face of the vacuum gauge. The discharge port should be open and free of obstruction. After starting the engine and bringing it to the proper rpm, apply the vacuum gauge assembly to the suction opening. A vacuum develops quickly, and the gauge should remain in position during the test.
If the vacuum gauge reads 25 feet, the pump will lift water 25 feet. If the pump has been checked and it pulls 25 feet of vacuum, the problem is elsewhere.
Test each time a pump is sent out to the unit's potential inability to prime.