Environmental Aspects

Troubleshooting - Water Treatment Systems

By Stan Royal |

04/01/20

Water is the lifeblood of the car wash. The systems to treat and supply this valuable resource must be understood and properly maintained. In this article, we will discuss maintaining and troubleshooting some of the most widely used water systems in the car wash process.

Pump Performance Curve.

Before we get into troubleshooting already installed systems, we need to address the most common problems associated with these systems. It is imperative that you know how much water and pressure you need for the job. Most equipment providers do this for you, and you should follow their specifications. But if you are adding ancillary equipment and you don’t know, find out, don’t guess. It is not your equipment provider’s fault if you add another arch and don’t tell them.

If your system uses pumps, sizing the pumps for flow and pressure is key. A pump that is supposed to do 50 gpm at 40 psi may only do 10 gpm at 60 psi. The pump/motor combo determines flow and pressure, not just the horsepower of the motor. If you are replacing a pump, use the one your equipment provider has spec’d for the unit. A pump with too much pressure can lead to problems such as water hammer, constant cycling on/off, and possible dead heading which can shorten the life of the pump and wreak havoc on your plumbing.

If the pump is too weak, you won’t get the results you need and could risk starving pumps on other equipment down the line. The chain reaction of not sizing pumping systems properly can be detrimental.

PLUMBING

You’ve done your homework, talked to your equipment provider, selected a pump, put it in, and you still have issues. Why? Plumbing! Plumbing is tricky in equipment rooms, and it is always best to leave it to professionals. Equipment manufacturers 

The check valve from a reclaim unit.
The customer thought the pump was bad.

take into consideration all of the elbows, etc. on their units, but often the owner is responsible for connecting to and from the unit at the specifications of the equipment provider. Follow these guidelines. If it says 2” sch 80 PVC, use 2” sch 80 PVC. Always make plumbing runs as short and direct as possible, and make sure they are airtight connections. This goes for inlets and outlets on the pumps. Many times, pumping systems use “trunk lines” that spur off and feed smaller lines. If you are adding something to the trunk line that your equipment provider has already set up, this will affect the performance of the system. When in doubt, consult a licensed plumber or your equipment provider.

Sizing units like water softeners is just as important as pumping systems. Water softeners can handle a specific flow of water at a pre-determined pressure loss across the system. If not sized properly, you can experience pressure drops and flow restrictions, which will affect everything downstream. It is a lot easier for 50 gpm to run through a 1-1/2” pipe than though a 3/4” pipe. Overflowing a softener can also cause the softener not to work. The amount of resin in a softener and the quality of the water determines how much water can flow through the system and effectively be softened. Therefore, it is just as important to know your water quality as well as the flow needed. Paying a couple hundred dollars for a water analysis is more than worth it. This will help your equipment provider size the softener properly and be able to give you a cushion for growth as well as those busy days. Remember: every function that you add after your original setup will affect the softener’s performance.

I have spent a lot of time here discussing the set up of water treatment systems instead of troubleshooting them. There is a method to my madness. If the systems are installed correctly, and to manufacturers’ specifications, that is 99 percent of the battle. Things go wrong with machinery. However, the better a system is set up, the easier it is to troubleshoot.

RECLAIM SYSTEMS

If the plumbing was done according to the manufacturer’s guidelines, many troubles will never occur. Remember when troubleshooting to look at the entire setup and not focus solely on the system. Consider, for instance, a system pump that is not priming correctly. The first thing to check would be the vacuum gauge (if supplied with unit). The vacuum gauge is usually located on the inlet strainer basket. This gauge indicates if there is an air leak or problem with the inlet plumbing such as a broken pipe or a joint that was not glued in properly (low vacuum) or a blockage in the line (high vacuum). Another cause of high vacuum is that the inlet suction line was not installed in a straight and direct manner. The downsides of these issues are the following: Low vacuum allows air to be introduced into the pumps on the system. This will damage pump seals and the system will not deliver the amount of water it is designed to provide. The system may never reach the required pressure to operate correctly. High vacuum indicates that the pump has to work harder to provide the water needed. This causes a strain on the pump and shortens its lifespan. It also will expand and contract other pieces of equipment on the machine.

Familiarize yourself with the gauges, prompts, and alarms of your unit. Read your manual. Each one of these can tell you a lot about what is going on. Start at the beginning of the system, and work forward. Here’s an example of what I am talking about:

Problem: The unit is running but very little water is coming out. However, my priming tank is full of water.

Troubleshooting: You have already determined that the pump is getting water, so look on the outlet side of the pump and move forward. First check your gauges. Use all of your gauges to determine where the restriction or loss of flow is showing up. Then, work between the gauges to pinpoint the issue.

Fouled RO system pre-filters.

For instance, if you have higher than normal pressure on both your filter inlet and outlet, you know your filter is not clogged and the issue would be after the filter. If inlet pressure is higher than outlet pressure, your filter is clogged, or a bypass valve/back flush valve is open past the filter. If you have low pressure on your filter, a bypass valve/back flush valve is open or the pump is clogged. If the valve is shut, the pump is clogged or the problem is between your pump and filter. If your breaker trips, you now know for sure that your pump is jammed or the motor is bad.

This scenario is true for any pumping system in the wash. When you go about the problem systematically, you can typically find the issue quickly. Do not just check the easiest things. Find the problem and fix it. It will cost you a lot less time and money moving forward.

Leaking pump seals are a common issue with reclaim systems. Reclaim pumps are quite powerful and will draw what is available up the line, be it mud, water, or air. Leaking pump seals are caused by the issues mentioned above as well as a couple other factors. If pit maintenance is not kept up, the pump may be pulling more sediment into the system. These sediments will eventually destroy the pump seals. Deadhead is when the pump is operating but the water is not being delivered, therefore causing the water to overheat and destroy the pump seal. Adjusting the pressure switch can solve deadhead issues.

Problem: System never shuts down.

Troubleshooting: About twice a week we get a call stating that the machine will never turn off and is always running. The reason a primary pump may always be running could be that there is a leak in the reclaim line after the system — maybe a stuck open solenoid or hung-up float switch. Once it is determined what is causing the issue and it is repaired, the pressure switch can be adjusted to the correct cutout point.

Problem: Cannot get the system to turn on properly.

Troubleshooting: Generally, this is chalked up to user error or not reading the instruction manual provided with the equipment. First make sure that the power has been correctly installed to the unit. Some systems need three-phase voltage and single-phase voltage to operate.

Systems should be started up in accordance to the manufacturer instructions. There may be a button you are pushing out of sequence or the priming process is being ignored.

REVERSE OSMOSIS SYSTEMS

The main issue we see with reverse osmosis (RO) systems is the water supply to the unit. Check with your manufacturer’s representative and find out the flow and pressure needed to operate the system. This type of system requires a consistent supply of water to operate properly. The main thing to consider is that you will need this pressure and flow in addition to covering the water needs of the other equipment. If there is only sufficient pressure when the other equipment is not operating, the RO system may not be operable during the busiest times. Sometimes a pressure boosting system is needed to keep the RO running consistently if pressure is the issue.

Failure to change the sediment pre-filter can also show up as a pressure fault on the RO system. The sediment pre-filter should be changed monthly to ensure proper flow for the RO system. If the filter is not changed on a regular basis it can hinder the operation of the RO unit.

Water Supply

Lack of a good water supply is generally the cause of pump failures on RO system. These high-pressure pumps rely on having the correct amount of clean water and pressure to operate. If there is less available than needed, the impellers will disintegrate due to overheating. The pump will not build enough pressure afterwards and will not allow the RO system to produce quality water.

Another factor that will cause pump failure is using a water source that is not properly treated before entering the RO system. If you are using a well to supply the RO, there may be several items that will need to be removed from the water before it can be sent to the RO. Since well water is usually not chlorinated, it brings other factors into the mix. Bio fouling from something in the well water can wreak havoc on an RO system, so can iron, hardness, magnesium, etc. All of the issues must be addressed when considering using a well. It may be the case that the cost of pre-treatment and the added maintenance it comes with make it more economical to run this system on utility-provided water.

The quality of the water being fed to the RO system is responsible for most RO issues. Remember that just because RO reject water appears to be of good quality, it may not always be the case. It is not advisable to feed the RO with reject water unless you have done a water analysis and discussed it with a certified water specialist. Use the reject somewhere else, and give the RO a fighting chance to do what is was designed to do.

Most RO systems have carbon tanks, and you may have a water softener as well. Although these systems can last as long as five to seven years if spec’d properly, they need to be checked. The carbon tank removes chlorine/chloramines from the water so the RO membranes do not get damaged. It is a good idea to check chlorine levels after your carbon tank every year. There should be no chlorine in the water. Use low-level test kits to get accurate readings. If there is chlorine present, have your service technician re-bed your tank. In the same fashion, check for hardness after your softener every year. If the unit is drawing brine and backwashing correctly, it may be time for a re-bed on this unit also.

Pumps and Membranes

If you do incur a pump failure on the RO system and have to replace the pump, there is one other very important step that needs to be taken. The damaged impeller stack may have distributed shreds of plastic into the top of the first membrane. This must be removed before restarting the system. If it is not removed the high-pressure pump will force the plastics shards into the membrane and cause irreparable damage.

After pump failure we must consider the membranes. Over-fluxing of the membrane (making it provide more permeate water than it is designed to put out) significantly reduces its lifespan. For some this is the only choice, and replacing membranes is accepted as the cost of doing business. For the rest of us, setting the RO correctly can add years of life to the system. We must remember that the outputs advertised on the membrane sheets are best-case-scenario numbers, and take note of the parameters mentioned on the spec sheet. In a real-world scenario, we have found that RO membranes will supply between 1,500 and 1,800 gallons per day per membrane. Therefore, when sizing an RO, go by this factor instead of what the unit claims to provide. You will get the amount of water needed to operate the site and not put any undue stress on the system.

Electrical Issues

The final thing common to all water treatment systems is electrical issues. Most pumping systems, including reclaims, are manufactured to run on voltages specified by the customer. This means, that by code, these systems have protective devices to shut down the pumps and controls when there is an electrical issue. If you are blowing fuses and/or tripping motor overloads, there is a reason. Typically, it starts with the power being supplied to the unit. Have a qualified technician check this at the first sign of trouble. Just replacing fuses and resetting overloads will cost you a lot more in the long run. Electrical protection devices are telling you there is a problem and resetting them is not the fix. Eventually you will burn up motors and start a chain reaction of issues that could be prevented from the start.

We hope this article has at least given you some perspective on the workings and troubleshooting of your water treatment systems. In closing, I would like to leave you with the most important bit of advice that I can give you. When it comes to electricity and high-pressure applications, always hire a certified technician to help you. If you familiarize yourself with your equipment and do preventative maintenance, your service calls will be less expensive and more productive. Trust me, it will not save you money to wait until the last minute to address the issue.

 

Stan Royal is president of Lakeland, FL-based Con-Serv Manufacturing.
You can visit the company on the web at www.con-servwater.com.

 



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