All About Valves In Plumbing Systems
A valve is a device that regulates, controls and directs the flow of fluids passing through a pipe. This mechanical device is used to stop water access, prevent backflow and adjust the water pressure in the system. Valves help in isolating sections of pipelines for repairs or stopping water flow in a water line in case of leak sprouts.
They are widely used in the commercial and industrial sectors, such as chemical plants, wastewater treatment centres, pharmaceutical manufacturers, and automobile production. They all rely on valves to control and direct fluids and gases.
Whether it is a globe valve or a float valve, they operate in a specific way and come in a range of styles designed to meet specific plumbing needs. Let’s look at globe valves and float valves and their applications.
Globe Valves: Working and Applications
A Globe valve is used to regulate the flow of fluids by opening and closing pipes. Unlike gate valves and ball valves, these valves are used to modulate and throttle fluid flow. The spherical part of the valve body constitutes the stationary ring seat. On turning the hand wheel knob, a revolving disc-shaped device is released from the stationary ring seat, spinning upward. It opens a Z-shaped passage that allows water to flow from chamber to chamber. The handle can be fully opened or partially opened and sealed to enable the throttled flow and reduced water pressure.
A Globe valve can be used for isolation, like a gate valve or a ball valve. But globe valves often show a greater pressure drop than the traditional shut-off valves. The curved Z-shaped interior of the globe valves is more flow restrictive compared to the ball valves and gate valves. This feature makes it highly suitable for handling fluids or steams at low pressures. Globe valves can close and open relatively slow to avoid water hammer. Under low pressures, they are not prone to leakages.
They are used in:
1. Cooling water systems.
2. Fuel oil systems.
3. Feed water or chemical feed systems.
4. Boiler and main steam vents and drains.
5. Turbine lube oil system and others.
Float Valves: Working and Applications
The float valve, also known as a ball-cock is used to control the level of water in a tank. This valve opens and closes on its own as the liquid level changes. The valve is mechanically operated with the help of a float. The rise and flow of the ball regulate the flow of water. The float valve controls the main valve with the help of a sub valve. The float valve must be installed in a horizontal position and not in a vertical position.
· They are mainly used in water tanks and in cisterns to maintain the proper water level and prevent excess flow.
· Float valves are used in low-pressure, high-pressure, and medium-pressure applications.
· These liquid level control valves are mostly used in the industrial refrigeration system. Float valves are used as throttling devices in a large refrigeration system. Float valves are used to control the level of the liquids as they are actuated lever valves.
