Valves

Valves are hardware used in regulating the flow, pressure or direction of fluids which can be liquids or gases in a system. They control the flow of these fluids through pipes or channels by either allowing them to pass through freely, partially or blocking them. There are various types of valves which are used in different fields such as plumbing, automotive industries, industrial processes etc. , which helps in controlling the flow of fluids and hence the operations are safe and efficient.

Different types of Valves

There are different types of valves and each is made for specific use and purpose. Common types include:

Gate Valve: These valves are employed for opening or closing of the flow of the fluid. It works by the opening or closing of a gate that is present in the valve. Gate valves are most suitable for use where there is the need to open or close a valve fully but not for controlling the rate of flow.
Ball Valve: These valves employs the use of a spherical ball that has a passage through its centre to regulate the flow of fluids. Turning the ball positions the hole with reference to the flow path or repositions it. Ball valves can be used for quick and tight shut off and are used where the valve will be operated frequently.
Butterfly Valve: It has a disc or vane that turns to control the flow of the liquid. The disc rotates to open or close the valve and offers control in a small package. Butterfly valves are used in applications where a light weight and compact design is necessary.
Check Valve: It is used to prevent backflow because it enables the fluid to flow in one direction only. The check valves are used to prevent the back flow of the fluid which can cause damage to the pumps and other related equipment.
Globe Valve: Controls flow by either opening or closing a plug or disc in the flow path. Globe valves are best suited for throttling services and for applications where a close control of the flow rate is necessary.
Pressure Relief Valve: Recieves and releases pressure from a system at a predetermined level in order to avoid damaging pressure levels. They are very important in safety applications to ensure the integrity of the system.
Solenoid Valve: Valve that is operated electrically by an electromagnetic solenoid that opens and closes the valve. Solenoid valves are widely employed in automation and control applications.
Needle Valve: Affords accurate flow control since the needle is long and thin, allowing the user to adjust the flow rate easily. Needle valves are used where there is a need to control the rate of flow and measure the amount of flow.
Swing Check Valve: Operates by a disc or flap that opens to permit flow in one direction and shuts when the flow is in the opposite direction. Swing check valves are most appropriate where there is need to prevent back flow.

Every type of valve is chosen depending on the application demands such as flow, pressure, and safety.

Different Valves Materials

Valves are made of a number of metals and these metals are selected based on their characteristics that are appropriate for use in the particular application. Common materials for valves include:

Stainless Steel: Being a material that is highly resistant to corrosion and has high tensile strength, stainless steel is widely used in valves particularly in applications that involve water, steam, chemicals and corrosive atmospheres.
Carbon Steel: Carbon steel valves are used in general industrial applications, where high strength is required. They are used for low to moderate temperature and pressure and applied in oil and gas transportation.
Brass: Brass valves are easy to machine and resistant to corrosion; they are used in plumbing, heating, ventilation, and air conditioning, and low pressure systems. They are commonly applied in water and air systems.
Bronze: Bronze valves are employed due to their ability to withstand wear and tear as well as corrosion especially in marine applications. They are widely employed in the systems where there is interaction with sea water and other aggressive media.
Aluminum: Aluminum valves are light in weight and do not corrode easily; they are used where weight is a major consideration such as in aerospace and automotive applications.
Monel: Monel is a nickel-copper alloy and is used in conditions which require high strength and heat resistance such as marine and chemical industries.
Inconel: It is a high-performance nickel-chromium alloy for extreme temperature and corrosive service application like aerospace and high-temperature industrial valves.
Hastelloy: Hastelloy valves are made from a nickel-based alloy that has high-temperature and corrosion-resistant properties, which makes it ideal for chemical processing and aerospace industries.
Titanium: Titanium valves are strong and resistant to corrosion and therefore can be used in applications that are more challenging such as in aerospace, chemical, and marine industries.
Nickel: Nickel valves are employed in applications where there is high resistance to corrosion and high temperatures as in the chemical processing industries and where there is high stress.

These materials are chosen depending on their ability to withstand corrosion, their strength, their heat capacity and their application in a given environment.

Features of Valves

Valves have several key features which include:

Flow Control: Valves control the flow of fluids in a system by either fully or partially opening or closing the flow passage, in order to control the flow of the fluids.
Pressure Regulation: Some valves are used to control pressure in a system such as pressure relief valves which prevent over pressure and protect the system.
Leak Prevention: Valves are designed in such a way that they are able to minimize or even eliminate leakage between the various parts of the valve so that fluids do not find their way out of the system.
Durability: Valves are designed and made of different material to suit different environmental conditions such as high temperature, pressure and corrosive fluids.
Actuation: Valves can be operated by hand or can be actuated by various types of actuators such as electric, pneumatic or hydraulic to operate the valve remotely or automatically.
Response Time: Depending on the type of the valve, the response time of opening or closing is different and this might be important in some applications where the change should be made quickly or with high accuracy.
Versatility: Valves are available in many categories and in various sizes and designs to perform various tasks such as on/off control, flow control and direction control.

Such features make it possible for valves to operate and control fluid systems in various sectors of the economy.

Applications of Valves

Valves are present in many industries and are used in many different ways. Some common uses include:

Water Supply Systems: They regulate the flow of water in municipal supply systems, irrigation systems, and home plumbing systems as well as pressure regulation.
Oil and Gas Industry: Control valves control the flow and pressure of oil and gas in pipelines, refineries and processing plants to perform functions such as opening and closing, pressure release and flow control.
Chemical Processing: Valves in chemical plants are applied as a means of regulating the flow of chemicals and other corrosive materials, pressure control in reactors, pipelines and storage tanks.
HVAC Systems: They control the flow of heating and cooling fluids in heating ventilation and air conditioning systems, which are used in energy efficiency and temperature regulation.
Automotive Applications: Valves are applied in engines, transmissions, and exhaust systems to control the flow of fluids, maintain pressure, and reduce emissions to meet the requirements of emissions standards.
Aerospace: Valves are used in aircrafts and space crafts for the regulation of fluids like fuels, hydraulic fluids and air and thus plays a vital role in the safety and operation of aerospace system.
Marine Industry: Valves are employed in ship construction and offshore platforms for controlling the flow of fluids and ballast systems besides controlling the operation of marine and naval equipment.

These applications demonstrate the importance of valves in controlling fluid systems particularly in various industries.