Troubleshooting Chemical Metering Pump Feed Problems - by Montana Prominent Rep., Able Wright

www.ablewright.com

It is critical that chemical feed systems function properly. When a formerly good system goes bad it can be frustrating to determine the cause, as there can be many issues involved. In the following we provide some repair and troubleshooting tips for operators…

1) Electrical – Check for proper power supply voltage and grounding. Test switching circuits to be sure they are operating correctly. Be sure to disconnect the pump power and close isolating valves when doing service work on chemical feed systems.

2) Diaphragms and Valves – Check for diaphragm damage and properly torque the liquid end screws. Diaphragm and valve service life is dependent upon proper system backpressure, operating temperature, and compatibility with the chemical being pumped. Chemical deposits on the valve ball/seat can cause poor valve actuation – clean or replace the valve. Pump suction and discharge valves are usually different; confirm that you have the correct part number and direction of flow.

3) Low Discharge Rate or Concentration – Check for leak free suction and discharge connections, O-rings, clogged inlet screen, cracked tubing, etc. Small suction leaks are hard to detect and can cause severe problems. Use a calibration column to determine the actual pump discharge rate. Check for adequate chemical tank levels and solution strength. Remember that some chemicals, such as sodium hypochlorite, off-gas and will degrade over time.

4) Control Valves – Be sure that backpressure and pressure relief valves are correctly adjusted. Backpressure valves aid by maintaining a consistent discharge pressure against the pump, and providing anti-siphon protection. Pressure relief valves will protect the pump and the downstream piping system in the event of an overpressure event. A backpressure valve and a vent valve are helpful during pump priming. Multi-function valves combine some, or all, of these features.

5) Maintenance & Cleaning - System components (inlet screens, valves, injectors, etc.) can become clogged, degraded, or worn. Tubing can become brittle with age, chemical contact, or UV exposure. It is recommended that all operators keep preventative maintenance / rebuild kits and spare components on hand. Replace worn components when necessary – nothing lasts forever. It is important to confirm the materials compatibility of your system components with the chemical being pumped – call us, if we can assist you with this.

6) Safety – Most chemical metering pumps are of the "positive displacement" type. Watch out for inadvertently closed valves or clogged discharge lines. The pump discharge pressure will rise rapidly and, unless protected with a pressure relief valve, can cause serious damage or personal injury. Wear eye protection and gloves when working with chemical feed equipment. For additional safety information, consult your equipment manufacturer´s recommendations. Read your chemical MSDS sheets and follow the guidelines carefully. Be Safe - Safety Pays.

Able Wright, Inc. is the Montana and northern Wyoming distributor for ProMinent Fluid Controls. Able Wright is a provider of water treatment equipment and technical services, specializing in disinfection and chemical feed for Montana, Wyoming, Idaho, and Washington.

www.ablewright.com

ProMinent Fluid Controls, Inc. manufacturers high quality, precision equipment used in chemical metering, measurement, and control for municipal and industrial applications. Products include chemical metering pumps, analyzers, sensors, controllers, transmitters, and engineered package systems.