PVC valves are primarily used for regulating or shutting off flow in a plumbing system and selecting the correct valve can be quite a task if understanding of the different types of valves is poor. This is as a result of the similar tasks that most of them perform. To know the correct valve to use requires an understanding of these valves, the best use of them and uniqueness of each one.
Plumbing problems remain a major issue faced by facilities managers and users of buildings. An additional problem is finding a competent plumber to deal successfully with a problem when such occurs. Often times, a plumber recommends the wrong valve due to a lack of full understanding of the various valves and their uses in a plumbing system.
There are many PVC valves notably ball valve, gate valve, check valve, butterfly valve and diaphragm valve.
Ball valve: It is possibly one of the best examples of a shut off valve. It utilizes a spherical seating as a means to allow or stop flow. A hole is located in the center of the ball which allows fluid to pass through it whenever the handle is turned on. If the handle is turned off at 90 degrees, the fluid will hit the side of the ball (the solid side) and the fluid stop. It also utilizes rubber O-rings in order to make the seal tight. These O-rings can be made from many different types of rubber, depending on what temperatures and chemicals they will come in contact with.
Check valve: Check valve is a regulatory valve because it controls the direction of flow. Common types of check valve are ball check valve and swing check valve. Ball check valve utilizes a ball to prevent backflow. A swing check valve utilizes a swing function to prevent backflow. Instead of using handles to open or close, check valve is activated by water flowing either with or against it.
Gate valve: Gate valve can function as regulatory valve and shut off valve. The valve utilizes a “gate” that controls flow. Whenever the gate is opened, it goes up into the upper section of the valve. A gate valve also utilizes hand wheel which makes it much easier to precisely control flow. Gate valve is easy to separate from a pipeline for repairs, cleaning, or maintenance.
Diaphragm valve: A diaphragm valve is likely the least popular available but serves a unique purpose for flow control. It is categorized a regulatory valve because of its best value to limit pressure. This valve controls flow with a diaphragm that either rises or lowers for a small amount of fluid to pass through.
Butterfly valve: A butterfly valve can perform as a regulatory or shut off valve. It has the ability to limit flow rather than being turned on or off if that is the objective. It can also perform the task of turning on or off a flow. However, the ball valve is a better shut-off valve than butterfly valve.
The role of facilities managers is to ensure the proper type of valve is selected for a plumbing system that requires repair or maintenance. To do this, correct valve size should be known. The measurement will depend on pipe size, material and operating flow. A larger valve will be necessary if the target is a zero pressure drop. Understanding the function of each valve will help to determine which valve meets the requirement.
