Types of valves used in plumbing
To control and regulate flow of water, various types of valves used in plumbing system.The pros and cons of each type are identified below.
Ball Valve
As name suggest, ball valve is made up of ball (sphere) with hole in it. In the open position, the hole in the sphere is in line with the pipe. In opposite when ball valve is in close position, the hole is perpendicular to pipe.The lever handle operates the valve, but also serves as an indicator for whether the valve is open or closed. Lever handle parallel to pipe indicates the valve is in open position. The advantage of this valve is we can not have precise control over the flow of water.The advantage is they provide excellent seal when in close position.Gate Valve
Gate valves control water flow by raising or lowering the gate, which is generally a piece of metal. There is a wheel or knob at the top of a gate valve that controls the height of the gate – this, in turn, affects the flow of water. The valve status i.e. whether close or open position can not be judge by the wheel or knob position. Gate valves provide a reasonable seal, but they should not be used to adjust flow – they should be open or closed.Butterfly Valve
Butterfly valves have a disc that is equal in size to the inside diameter of the pipe. This disc is attached to a lever handle that rotates the disc, which adjusts the flow of water. The main drawback to butterfly valves is that the control disc is always present within the flow of water (even when fully open) so there will always be a pressure drop when using them.Butterfly valves allow for fairly precise control of flow. They typically rely on a gasket to provide a full seal, which can become a maintenance issue.It is closed using a wafer or disc that is mounted on a rod that is secured in the middle of the valve.In the open position the disc is parallel to the pipe in the closed position the disc is perpendicular to the pipe closing off flow.Most times the handles are spring loaded and allow you to lock the valve into a certain position.Angle Valve or Stop
Type of globe valve design, having pipe openings at right angles to each other. Usually, one opening is on.Angle stops are named because they are manufactured at a 90degree angle, they are used as shut off valves at the water intake of plumbing fixtures or appliances. The angle valve is not meant for high pressure applications.Globe Valve
Globe valves get their name from the globe-like or ball-like appearance that the body of the valve has.A globe valve can be used to regulate flow in a plumbing line. Globe valves are used to throttle or limit the flow of water. They have a stopper that is raised and lowered by a wheel or knob on a shaft. The stopper seals into a baffle to stop flow. Globe valves are used in situations where the flow needs to be adjusted regularly, but also where the flow doesn’t have to be fully open since the baffle restricts flow.The handle is attached to the stem which raises and lower the disc into place.Check Valve | Non return valve
A check valve is a one way valve in that is has one inlet and one outlet that allows the a liquid to travel in one direction. Check valves are used to keep water flowing in only one direction. They are generally not operational. A back-flow preventer is a type of check valve. A ball-check valve uses a ball to stop the flow of water in the wrong direction. A diaphragm-check valve has a rotating disc or rubber flap that is pushed to seal the opening in the event of flow in the wrong direction.The majority of check valves used in the plumbing industry work automatically meaning when the pressure or direction changes the valve slams shut.A stop-check valve is operational and allows a user to completely stop all flow – even flow in the correct direction. It will not allow backward flow when open.pressure reducing valve
A water pressure reducing valve is a device that is installed on a water service either in a commercial or residential building in order to reduce the buildings water pressure to the desired psi. This mechanical device uses a spring and adjustable diaphragm in order to increase or decrease the water pressure within the water supply service. Pressure reducing valves come in multiple sizes and can be attached to copper pipe or plastic composites.Flush Valve
The diaphragm flush valve remains largely unchanged. The flush valve is comprised of two chambers, the upper and the lower. When the valve is not used both chambers are filled with water and equalized by the water supply pressure and it is kept equalized by the by-pass orifice. More about the by-pass orifice in a second. The handle is attached to a handle assembly, the flat end of the handle is butted up against the flat end of the operating stem. When the handle is depressed it pushes the operating stem which trips the stem of the diaphragm. This stem rocks the diaphragm out of the seat thereby releasing the water from the upper chamber. Because there is now less pressure in the upper chamber the diaphragm is pushed up from the water pressure in the lower chamber and flushing begins. The diaphragm slowly re-seats itself as water from the lower chamber enters through the by-pass orifice equalizing pressure between the two chambers.Air release valves
Air Release Valves function to release air pockets that collect at each high point of a pressured pipeline. Air Release Valves can open against internal pressure, because the internal lever mechanism multiplies the float force to be greater than the internal pressure. This greater force opens the orifice whenever air pockets collect in the valve. Air Release Valves are essential for pipeline efficiency and water hammer protection.