Harwil has manufactured low-cost, highly-reliable flow and level switches for over 50 years. Our mission is to help companies succeed by providing them with extremely cost effective and reliable products with the quickest shipments in the industry. Our products are very versatile, giving us the ability to cover many different industries. We currently supply the Pool and Spa, Water Heating/Cooling, Irrigation, Pump and Tank Manufacturing, Water Treatment, Carpet Cleaning, Geothermal, Heavy Equipment, and Pressure Washer Industries, with many more on the way. The materials utilized in the manufacturing of our products allow us to be used in virtually any fluid, with temperature ranges up to and including 250°F (121°C); as well as pressures reaching 300psig. Simply tell us the type of environment your system contains, and we will work with you in deciding what materials are most suitable.

Chillers & Boilers
When chilling or heating liquids in high input / output systems, you need to ensure that the liquid (usually water or glycol) is flowing or it could freeze, boil or vaporize. Many manufactures of these types of equipment use the Harwil Flow Switches to verify that there is sufficient liquid flow. Harwil switches don't just indicate flow, but can actually indicate a specific minimum or maximum flow rate. Multiple switches can be used to indicate a range of flow rates. Virtually all of our flow switches are used by chiller and heater manufacturers depending on their individual requirements. Our flow switches are Noryl, Fortron, Brass or Stainless Steel.

Commercial Cleaning
Just about every carpet cleaning trunk in the world relies on Harwil Liquid Level switches. The L-21N Level Switch has been the industry standard level switch for years because; 1) it has no seals, so it can't leak; 2) it has up to a 5 inch hysteresis so pumps don't cycle too often and the water motion does not make it switch when it shouldn't; 3) it's super durable and can bounce around in the back of the cleaning truck for years. In many of these cleaning systems the water is heated and our flow switches are used to detect sufficient water flow so the heater can turn on without overheating. The levels of the soaps and chemicals are monitored and controlled with our level switches.

Irrigation
Harwil switches are used in irrigation to insure against pumps running dry, control chemical feeders, and indicate when a water line has broken. Often fertilizers are injected into the flowing water, but it must only be done when the water is flowing. The Harwil Flow Switch "proves" water flow, allowing the chemical feed system to run. Harwil flow switches can indicate that water is flowing when it should not be flowing, warning that a line is broken or when water isn't flowing when it should be. Harwil Level switches can be used in storage tanks to maintain liquid level or show when the level is too high or too low. We have all sizes and shapes of Level Switches made from stainless steel to brass to engineered resins for using in just about any fluid. Harwil's Wireless System has Pump-Up and Pump-Down control build-in, just hook up the level switches. This Wireless System can keep your elevated water storage tank filled that is way up there on the hill, from the pump in the pond that is way down here, and you don't have run a signal wire between them. No trenches, not overhead wires, no animals eating the wires or humans damaging the wires.

Municipal & Waste Water
Locations that process waste water need to determine if water is flowing at the correct minimum rate to ensure that the water treatment processes function correctly. The Harwil Q-5 and Q-16 Flow Switches in Brass, or Q-5SS Flow Switch in 316 stainless steel, are used for these applications. This model is robust and will function without fail for years and years. The Harwil Wireless Switch Control is also popular in these environments. Often the maze of wires and pipes makes adding more wires difficult. The Wireless Sending Unit is attached directly to the Q-5 Flow Switch and the Wireless Receiving Unit is installed at the controlled device location. The switch's position is transmitted which operates a 15 amp relay at controlled device location. Harwil's Harwil Wireless Switch Control can actually work with any kind of switch, not just Flow and Level Switches.

Pool & Spa
Harwil Flow Switches are used by almost all of the major pool equipment and spa manufacturers in the world. Harwil Flow Switches are a critical part of the new generation of salt water chlorine generators which are used to replace adding chlorine to a swimming pool. The titanium plates in the generator must have water flowing across them when operating. The Harwil switch ensures that the proper amount of water is flowing eliminating potential damage to these expensive plates or chlorine gas build-up. Harwil flow switches are also used with pool and spa water heaters. If the heater started without sufficient water flow the heating system would quickly be damaged. Only the Harwil Flow Switch ensures that there is exactly the right water flow as specified by the heater manufacturer.

Water Treatment
Harwil's Flow and Level Switches are ideal for water treatment and all of the resins used are NSF listed for drinking water applications. The most common use is for chlorinating or conditioning drinking water from a well or a storage tank. A Flow Switch is used to detect the water flow, usually when a faucet in the home is opened, which turns on a chemical feed system or some other type of water treatment. Harwil has created a full line of Chemical Feed Controllers (CF112, CF-12, CF-8) that are very easy to install and use. These just are installed on the main water line and they turn the Chemical Feed Pump on and off as water is used in the house. Harwil has models for any application and pipe size.