What Are Valves?
Valves are essential parts of water supply systems, wastewater treatment plants, and chemical plants in homes and businesses. The uses are to direct water flow, shut off water access, stop water from flowing backward, and change the water pressure within a system. Valves are used to connect pipes and control how much water flows through them.
Ball valves are made with a sphere with a hole that can turn. When the valve is open, the pipe goes through the hole in the globe. The hole is straight across from the pipe when the sphere is closed.
The lever handle turns the valve on and off, showing whether the valve is open or closed. The valve opens when the lever is in the middle of the pipe.
|Nominal Pressure||2.5 MPa (25 bar)|
|Max. Working Temperature||100°C|
|Working Media||Water (water supply systems and central heating)|
|Ball Finish||Chrome Plated, Polished|
Most ball valves have hard stops at 0, 45, and 90 degrees, making it hard to control the flow precisely.
The gate, usually made of metal, can be raised or lowered to control how much water flows through the valve. At the top of a gate valve is a wheel or knob that changes how high the gate is.
This, in turn, changes how the water flows. Unfortunately, the wheel doesn’t show whether the valve is open or closed or how much it is open or closed.
|Nominal Size||11/2inch to 14inch|
|Working Temperature||10℃ – 50℃ (15°F – 120°F)|
|Max. Working Pressure||150 PSI|
|End Connectors||Flanged End|
Gate valves make a good seal, but they shouldn’t be used to change how much flow goes through them. Instead, they should either be open or closed. Gate valves may not be solid, and corrosion can cause them to get stuck in either the open or closed position.
Globe valves are used to stop the flow of water or slow it down. They have a stopper moved up and down by a wheel or knob on a shaft. The flow stops when the plug seals into a baffle.
|Nominal Size||1/2″ to 2″ BSP|
|Max. Working Temperature||180°C|
|Nominal Pressure||13 BAR|
|Threaded Type||NPT spec ANSI B2.1|
|Body Material||Brass or Stainless Steel|
Globe valves are used when the flow is often changed, but the flow doesn’t need to be completely open because the baffle slows it down.
Globe valves are called that because the valve’s body looks like a globe or a ball.
With a check valve, water can only flow in one direction. Most of the time, they don’t work. A type of check valve is a back-flow preventer. A ball-check valve stops water from going in the wrong direction using a ball. A diaphragm-check valve has a rotating disc or rubber flap that can be pushed to seal the opening if flow goes in the wrong direction.
|Size||1/2 inch－4 inch|
|Working Temperature||Up to 350° F|
|Pressure||Up to 6000 psi|
|Threaded Type||NPT spec ANSI B2.1|
|End Connection||Duolok, Griplok, and Unilok tube ends male and female NPT and BSPT|
|End Connection Size||1/8 to 1/2 inch|
|Body Material||UPVC, Brass, Stainless Steel|
A stop-check valve works, and it’s possible to stop all flow, even flow in the right direction. When open, it won’t let anything go backward.
Fixture Shutoff Valve
Fixture shutoff valves let you turn off the water to your sink or other fittings without using your home’s main shutoff. These cheap little valves aren’t used very often, but when they are, they sometimes leak. A leaking shutoff valve is easy to fix with a new part that is the same as the old one. Home supply shutoff valves come in several different styles:
- Straight Shutoff Valve
- Angle Stop Valve
- Three-Way Stop Valve
- Compression Shutoff Valve
- Copper Sweat Stop Valve
- Iron Pipe Stop
- CPVC Shutoff Valve
- PEX Shutoff Valve
- Push-Fit Shutoff Valve
Here are four types of valves you might find on a modern bathroom faucet.
Compression valve type:
Faucets with compression valves have been around the longest and cost the least. Most bathroom faucets have separate handles for hot and cold water. To stop the flow of water, you must tighten the handles. Rubber or plastic washers inside the bathroom faucet valve can rust or crack, breaking the seal and letting water out. Washers are cheap and easy to change, which is a good thing. Just remove the valve assembly for the bathroom faucet and put it in a new washer.
Cartridge valve type:
Cartridge faucets have a stem cartridge that moves up and down to control how much water flows. The cartridge valves on bathroom faucets are very durable.
Ceramic disc valves type:
Ceramic disc valves are very durable. Bathroom faucets with ceramic disk valves have one handle on a vast, cylinder-shaped body. Two ceramic discs overlapping in a broad cartridge control the water flow and temperature. Hardened ceramic is a rigid material that doesn’t rust or wear down quickly. Like cartridge valves, ceramic valves can be changed.
The words “ball,” “cartridge,” and “disc” are also used to describe other kinds of valves that aren’t just on faucets. Because of this, the words are put together with the word “faucet” to set these valves apart from the more general valve styles. If you ask for a “ball valve,” you’ll probably get the available kind, not one for a faucet.
Pressure Reducing Valve
The Pressure Reducing Valve (PRV) keeps your home safe from water pressure that is too high for your plumbing fixtures to handle. Your house’s water pressure should be between 40 and 80 pounds per square inch (psi). This is standard. If the water pressure from your water provider is more than that, a pressure-reducing valve is put on the home’s main water line to lower it to a safe level.
The Pressure Reducing Valves are made with rubber parts and springs that will wear out or get clogged with things in the water over time. Most PRVs break down slowly over time.
|Size||3/8″, 1/2″3/4″ 1″|
|Orifice||Up to 3.6 Cv|
|Max. Pressure||400 psi|
|Reduced pressure ranges||15psi to 75ps|
|End Connection||Standard – NPT/BSP Female|
|Application||Air, Gas, Water, Steam|
Pressure Reducing Valves are installed in heating systems, appliances, and buildings to protect them from damage caused by high inlet pressures from the mains water supply. This is accomplished by lowering the outlet pressure to a more manageable level.