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Although proper pump selection, system design and installation are vital steps in establishing a successful self-serve carwash, a thorough, planned maintenance program is the key to optimum performance and extending the life of your carwash pump.The important parts
There are several important factors to consider when establishing a maintenance program, but seals, valves and oil are the three most important parts.
All components of a carwash system should be inspected at regular intervals, and particular attention should be given to these three areas.
1. Seals: These are wear items and a pump manufacturer can only give a guideline as to the life of a seal.
The duty-cycle of a carwash, the hardness of the water, the soaps and other chemicals, the water supply, and filtration all contribute to the wear of the pump seals.
A maintenance cycle should be established for a pump and system based upon the inspection of the pump at its initial 1000 to 2000 hours, or if changes are made to the carwash.
Consistently perform service on this schedule to keep the pump in optimum form. Running the pump with worn seals only encourages other components to fail.
2. Valves: These are also wear items, but because they are metal parts, they typically last a bit longer than seals, so they may not require changing each time the seals are replaced.
However, pump valves should be inspected each time the seals are replaced, until their life cycle can be established.
3. Oil: Metal moving parts need lubrication for optimum performance and life.
It is easy to skip an oil change when a pump appears to be running well, but delaying an oil change can put the pump in jeopardy and can ultimately shorten the life of the carwash pump.
The pump will maintain a trouble-free performance for a longer timeframe if the maintenance called for by the manufacturer is performed on a regular basis.System components
Each time the seals and valves are replaced, the entire system should be reviewed for potential problems. Primary and secondary pressure relief valves should be examined. O-rings, seals and valves in these valves also need periodic replacement.
Some system accessories need to be considered on a more frequent basis. Some suggestions to keep a carwash pump and system in optimum form include:
Daily — Clean the inlet supply line filters. Check the pump oil level and quality. Inspect for any oil or water leaks.
Weekly — Inspect and adjust the belts or pulleys. Inspect the plumbing for any loose fittings, worn hoses or other problems and correct them immediately.
300 - 500 hours — Change the oil. If you are using oil specially formulated for the pump, change it every 500 hours or as indicated. Otherwise, a more frequent change every 300 hours might be advisable.
1500 hours — Initially inspect the seals and replace them if they are worn. If there is no evidence of wear at this time interval, recheck the seals at 500 hour intervals, until wear is observed.
This interval will become the regular seal maintenance cycle. Each pump is different, so it is best not to rely solely on the experience of another carwash.
3000 hours — Typically, the valves do not need to be serviced as often as the seals, but time can be saved if they are inspected on the same schedule as the seals.
If the valves do not need replacing immediately, continue inspecting the valves at 500-hour intervals until wear is observed.Knowing why to service
If during the course of day-to-day operations a difference in pump performance or appearance is observed, the operator will need to investigate the cause of the condition.
The site manager or owner should document all conditions with date, condition, and cause and solution because this history will be useful for future pump or system maintenance.
If there is no diagnosis chart provided, contact the manufacturer or representative for recommendations before proceeding.
A few items to consider before performing maintenance include:
- Determine the exact model number of the pump;
- Decide if you are capable and have the proper information to perform the service;
- Do you have an updated service manual showing the current parts?
- Do you know the torque requirements for all the bolts, screws, retainers, plugs and gauges?
- Are there any technical updates from the manufacturer for the pump?
- Is this a repeat repair, and do you need to look at adjusting your maintenance time cycle or making changes to your system?
When a problem is observed with a self-serve carwash system, the operator may need to look outside the pump to find the actual cause.
The following are a few examples of what could be contributing factors.
Example A: Pump runs extremely rough — There are two parts within the pump that are worth checking: seals, which may have worn or valves that are worn or stuck.
If the seals or valves are wearing out prematurely, the operator should test the water supply to see if it contains abrasive particles that will cause the seals and valves to fail.
A stuck valve may be caused by foreign matter in the pumped liquid.
Clean the valve and inspect for a smooth seating surface. Find out where the debris is originating and eliminate the problem.
Open supply tanks are generally the culprit. Check the water-line feeding the pump. Inlet restrictions or air entering the line can cause severe cavitation.
The pump will run rough or lose pressure and the valves will become pitted and seals will wear quickly.
Correct the problem by increasing the size of the plumbing to the pump inlet, removing any restricting fittings or elbows, and checking for an air tight seal on all valves and fittings.
Example B: Pulsation — Some pulsation is inherent in a triplex pump design. A triplex (three piston/plunger) pump design reduces the pressure variation to one-seventh the level of a two-piston pump.
Excessive pulsation is generally a result of no pulsation dampener installed in the system, a faulty bladder, damaged pulsation dampener, or foreign material trapped in the inlet or discharge valves of the pump.
If not corrected, excessive pulsation causes damage to the pump, couplings, valves and other components that are forced to absorb this excess energy.
Check the pre-charge on the dampener and, if low, recharge it or replace it. Check the valves, clean or install a new valve assembly.
Example C: Premature seal failure — There are a number of possible causes for seals to wear prematurely including:
- Abrasive material in the liquid being pumped;
- Excessive pressure and/or temperature of the pumped liquid;
- Running the pump dry;
- Starving the pump of adequate inlet liquid;
- Misalignment of the plungers; or
- An eroded manifold.
There are a few solutions to consider such as raising or lowering inlet pressures, setting up a proper inlet filtration system, and adjusting the temperature of the liquid.
If the manifold is eroding, check for compatibility between the manifold material and the liquid being pumped.
Whether the two are compatible or not, you will still need to replace the eroded manifold, but you may be able to upgrade to a different material that will last longer.
Darla Jean Thompson has been with CAT PUMPS, a maker of industrial, reciprocating, high-pressure, triplex pumps, for 35 years. For more information on this topic, email firstname.lastname@example.org.