Inspection Tests – What’s the Condition of Your Waterous Pump
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Inspection Tests – What’s the Condition of Your Wateorus Pump
A regular testing program offers the best means of determining the actual condition of a pump and its accessories, and permits locating problems before they cause trouble. At a fire, it is usually difficult for the pump operator to observe the pump closely enough to determine its true condition.
Conduct these tests either every month or annually, as outlined below.
Vacuum Test — Remove all caps except openings without valves. Close all discharge, intake, drain valves and other similar openings. Operate priming device to create a vacuum of about 22 in. Hg/.735 atmospheres in pump, then stop primer and engine.
Watch pressure gage; if vacuum drops more than 10 in. Hg/.334 atmospheres in five minutes, listen for air leaks around packing glands, gaskets, valves, etc. Replace gaskets, repack or otherwise repair source of trouble.
Pressure Test (Hydrostatic) — Connect pump to a hydrant or other pressurized water source. Remove all caps except openings without valves. Close all discharge, intake, drain valves and other similar openings. Turn on inlet valve and “crack” highest discharge valve on pump to expel air from pump. Close discharge valve. Carefully examine pump and accessories for leaks. Replace gaskets, tighten joints, repair valves, adjust packing if so equipped, to eliminate leaks.
Running Test — Run pump for at least 15 minutes from draft, if possible. Drafting is best because the pump is then more sensitive to defects than when connected to a pressurized water source. Check the following:
Priming Ability — If pump does not prime readily (30 seconds for 1,250 GPM [4,731 l/min] or less; 45 seconds for 1,500-2,000 GPM [5,678 to 7,570 l/min] pumps) stop pump and deter-mine cause. An additional 15 seconds may be required if the pump is equipped with a 4-inch or larger front or rear intake.
Shaft Seal — Packing: Packing should leak a small amount to keep it cool and lubricated. Refer to the operation and maintenance manual for the specific pump for leakage rate and packing adjustment.
Mechanical Seals — Mechanical seals should not leak. Refer to the operation and maintenance manual for the specific pump for maintenance.
Transfer Valve (series/parallel pumps only) — With the pump running at idle speed, switch valve from one position to the other several times to make sure it operates properly. If the transfer valve is equipped with a grease fitting, lubricate it in accordance with maintenance instructions for the pump involved.
Shift — Check shift mechanism to make sure it is working properly.
Performance — Check pump speed at rated pressure and capacity.
Accessories — Operate all discharge and intake valves, relief valves, drain valve and similar accessories to make sure that they all function correctly. If any power accessories are installed, be sure to operate the manual overrides (if connected) to make sure they operate properly.
Indicating Lights — Check to make sure they are working properly.
At least once a year, test the pumper to determine if it is capable of meeting the requirements outlined in NFPA 1911, Tests of Pumps on F.D. Apparatus. Compare the pump and engine speeds observed in these tests with those in the acceptance and other previous tests. If the speeds observed in the latest tests are much higher, the pump probably requires some repairs.
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