Water-level Control Valves
Water-level control valves automatically maintain the level of water in livestock waterers or storage tanks. There are two major types of valves: diaphragm and mechanical (lever operated) valves. Note: photos of various valves described in this section can be found in the photo gallery pages.
The flow rate is a major consideration when selecting a water-level control valve. The valve flow rate should match or exceed flow rate needed during the period of the highest livestock water demand, which is based on the type and number of animals along with the season of the year the tank will be used. Please review the “Daily Water Requirements for Livestock” section of this handbook for instructions on how to calculate the maximum water demand.
The incoming water pressure is another major factor when selecting the water-level control valve. Gravity-flow valves are designed for low pressures of 0 to 30 pounds per square inch. These valves are designed with larger orifices than higher pressure valves so the desired flow rate can be achieved. When the water pressure is higher than the design value, the valve may fail to completely turn off the water, causing tiny flow seeps not noticeable when the waterer is in use, but the seep can cut a groove in the orifice or rubber seat over time.
An additional consideration is the valve placement. Many livestock waterers or tanks are controlled with valves that are placed at or above the surface of the full tank, while other valves are designed to be placed under the water surface or at the bottom of the tank. Public water supply organizations often require all livestock water valves on their systems be “anti-siphoning,” which means there must be air space between the water discharge point and the pool of water in the livestock tank. This keeps water in the livestock tank from contaminating the public water supply.
Water-level control valves come in two major types: diaphragm operated or lever operated.
Diaphragm-Operated Valves
Diaphragm-operated valves tend to have full-flow water flow to the selected water level, when the diaphragm then completely closes. These valves are usually enclosed in a plastic case. Diaphragm valves have a more complicated system including two tiny passages that sense and activate the diaphragm action. These tiny passages can be cleaned and then reinstalled by the producer, but the information that accompanies the valve may not discuss this maintenance or repair.
Diaphragm-operated valves tend to have an operating range of 5 to 150 pounds per square inch and may not be suited for gravity-flow systems.
Examples of diaphragm valves are:
- Jobe Mega flow
- Jobe Topaz
- Jobe Vortex
- Apex Xtraflo
- Hudson — must be used vertically and cannot be used in a submerged placement.
Lever-Operated Valves
Franklin, Mirico, and similar valves found in many different brands of commercial waterers use a single plunger rubber seat (Photo 4). These can have orifices of three different sizes for different pressures and flow rates.
DURAPRIDE Pride of the Farm and Hawkey\Brower valves use one diaphragm seat and one “O” ring to create a seal (Photo 5).
Richie uses a plunger seat to seal and has three orifices for flow rates and pressure ranges up to 80 pounds per square inch.
Roberts and Watts valves are similar and are typical of brass valves used in agriculture. These often use threaded brass rods to attach the valve lever to the brass or plastic float. They come in a range of sizes which can be used to meet the desired flow requirements. A replaceable plunger rubber fits into a seat to shut off the valve.
Brass Valves
Watson valves are available in a wide range of sizes and flow rates (Photo 6). They are frequently used in tire tanks but are also ideal for gravity-flow and other waterer applications. The valve consists of an aluminum float attached by a chain to the lever.