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Maximize Chemical-Injector Pump Performance (Carwash Industry)  06-02-2002 There are two primary pump classifications that spawn a multitude of  subgroups, or branches. Displacement and dynamic are both essential  pumps that are used throughout the carwash industry. Displacement pumps include two important categories,  and further sub-categories: 1.) Reciprocating Diaphragm Piston 2.) Rotary Peristaltic Screw Vane Dynamic pumps also include two categories: 1.) Centrifugal Axial flow (impeller) Radial 2.) Special effect Jet Gas Hydraulic Carwashes today use the majority of these pumps.  Centrifugal pumps, which are an essential asset in low water pressure  areas, are used for pumping large amounts of water. Piston pumps are important in water reclamation  and reverse osmosis systems. Displacement style pumps, or more specifically  reciprocating diaphragm, are the preferred way to pump carwash  chemicals; rotary peristaltic pumps are also used for pumping specific  chemicals. Delivery pumps These pumps are properly called displacement pumps.  Remember, both reciprocating diaphragm and rotary peristaltic are often  referred to, in the industry, as chemical dispensers, injectors,  metering pumps, diaphragm pumps or chem-feeds. The rotary peristaltic is often referred to as a  tube or squeeze-tube pump. Most modern carwashes come equipped with chemical  injector pumps as standard equipment. These diaphragm pumps inject  precise amounts of carwash chemical into the wash line. The chemicals  used vary; they could be soaps or various waxes, drying agents or  under-car cleaners.   Displacement style pumps, being made here, are the preferred way  to pump carwash chemicals. These diaphragm injector  pumps are not standard off-the-shelf pumps — they are a hybrid variety.  These special injector pumps are required to start and stop, in some  cases, hundreds of times per day. They are also required to: Handle a wide variety of chemicals Be completely adjustable Handle wet environments Be field serviceable. Chemical injectors require periodic maintenance, with  the amount of maintenance depending on the level of activity at the  wash.   Get better performance To maximizing your chemical-injector pump  performance: Avoid running chemical containers dry. While  the pump may not be mechanically harmed, pumping air will cause the  valves to build up a residue of dried chemical.   After changing out chemical containers, make  sure the pump is primed and most air is purged out of the pump head.   Inspect and, if necessary, replace your  diaphragm at least every six months. Also inspect the top and bottom  valves -- clean or replace as necessary.   Keep spare liquid ends (assembled pump head  kits) handy. It's far easier to replace a diaphragm and pump head  complete with valves (usually just four screws) than it is to detail  every o-ring and ball seat. Time is money.   Inspect your foot-valve strainer quarterly.   Chemical injectors are easy to prime when the  discharge (pressure) line is removed or vented. After the pump is  primed, reattach the discharge line to the top pump-head valve or  close the vent relief.   Always wear eye protection when working on  chemical injectors or when changing out containers.   Avoid changing chemical brands without  researching the compatibility on your injector pumps.   A flow indicator installed on the suction  tubing of your injector is an outstanding diagnostic tool. At a  glance, you can see if the pump is working properly.