Valves

Types
Although there are countless valves that can be credited to control the flow of liquids but they are basically divided these categories -

Stop valves - This category of mechanical valves include all those valves that are used to shut off or partially stop the flow of the fluid. They are controlled by the movement of the valve stem and can be further classified.

Globe valves - are the most commonly used valves having features like straight-flow, angle-low, and cross flow. The Gate Valves are used in case of straight line flow of liquids when minimum restriction is required.

Butterfly Valve - As per the name, these valves can be used in a variety of system abroad ship. They are light in weight, small and relatively quick acting. Resilient body, butterfly disk, a stem, packing, a notched positioning plate, and a handle are a few important components of butterfly valves.

Ball Valves - As the name goes, ball valves are installed to stop or start off the flow of liquid. These valves perform the function that are similar to the disk in the globe valve and are quick actiong in nature and methodology.

Check Valves - These are important mechanical valves that aid in allowing the liquid to flow in just one direction. Used generously in chemical process plants, water purification plants, petrochemical industries these valves prevent reverse flow of the fluid and hence avoid contamination.

Poppet Valves - The poppet valves are used to control the flow of exhaust and intake gases in automobiles. This type of valve is controlled by the camshaft and requires to be very accurate and durable over extended use at high temperatures.

Materials
Almost all over the world stainless steel, titanium, Stellite, Hastelloy, brass, or nickel are the most common materials used for the manufacturing pf valves. In addition, different types of plastic, such as ABS, PVC, PP or PVDF too are being used now for the construction of these mechanical valves.

Application
Huge variety of valves having unlimited applications can be found in the world. Ranging from inexpensive simple, disposable valves to items in exotic materials that in some instances cost thousands of dollars, the use of these valves may be found inside common household items including liquid or gel mini-pump dispensers and aerosol spray cans. Mechanical valves are used extensively throughout the engineering plant and other parts of the ship in a variety of systems.