Single Knob Water Valve Shower Mixer Types

Cartridge Valves

• Cartridge valves are perhaps the most common type of single-handle shower valve design. Unlike other valves, a cartridge valve is a one-piece design. The valve handle is attached directly to the tip of the valve. Pulling the handle away from the shower wall slides the top half of the valve out of the lower half and allows water to flow to the showerhead. Within the valve are a number of small holes, sometimes referred to as water jackets. Twisting the valve handle changes the alignment of these water jackets and determines how much hot water mixes with the cold water. Cartridges were traditionally made of metal, but most modern designs are made of plastic.

Ball Valves

• Although ball valves are commonly associated with kitchen sinks, they are sometimes used in showers. Ball valves feature several independent components that work together. A metal or plastic ball fits inside of a housing. Within the base of the housing are three holes. One hole directs cold water to the valve and a second hole directs hot water to the valve. The third hole directs the mixed water to the shower head. As the valve handle is rotated, slots cut into the side of the ball align with these three holes to adjust the water temperature.

Disk Valves

• Disk valves look substantially similar to ball valves, but their construction is different. Whereas ball valves feature a ball, disk valves contain a cylinder fitted with two ceramic discs. The disks feature inlet holes for hot and cold water and an outlet hole that directs the mixed water to the showerhead. Lifting the valve handle causes one disk to slide across the other disk. The change in alignment is what determines the water temperature. Because ball valves and disk valves have no distinguishing exterior features, you must remove the valve handle to determine whether the faucet is fitted with a ball or with a cylinder.

Mixer Valve Problems

• Regardless of the type of faucet, problems are an unfortunate inevitability. You can often resolve many problems by replacing one component of the valve, but it some cases you may have to replace the entire valve. It is important to turn the shower’s water supply off before disassembling the valve. If a cartridge faucet leaks, chances are good that the leak is caused by worn O-rings that you can replace. If you notice a decrease in water flow, the valve may be clogged with sediment and require replacement. If a ball faucet leaks, try tightening the metal cap located behind the handle. If the leak persists, the problem is most likely caused by worn-out valve seats, springs, or by a damaged ball. Repair kits are readily available and include all of the necessary parts. If a disk faucet leaks, you can most likely trace the cause of the leak to dirty seals or cylinder openings. Replace the cylinder if the problem persists.