What Are Valves?

Valves are ubiquitous in our homes, although their presence often goes unnoticed until a plumbing issue arises. Their primary purpose is to regulate, direct, or control the flow of liquids or gases by opening, closing, or partially obstructing various passageways. Here’s a comprehensive guide to the different types of household valves and their applications.

Normal Valve Types

Ball Valves

• Description: Ball valves feature a rotating sphere (ball) with a hole through the middle. It allows passage when aligned with the flow, but when turned, it blocks it.
• Usage: Commonly used as shutoff valves for water main lines, appliances, and outdoor hose bibbs.
• Advantages: Offers a durable seal, is quick to open or close, and is reliable over long periods without use.

Gate Valves

• Description: These valves employ a gate-like disc and a threaded stem to regulate flow. By turning the handle, the gate either rises or lowers.
• Usage: Used primarily as shutoff valves in larger home plumbing systems.
• Advantages: Provide a full flow of water and a robust seal when closed. However, they can become difficult to turn over time.

Globe Valves

• Description: Characterized by a spherical body and an internal baffle. The valve’s stem and handle control a plug which can be raised or lowered over an opening.
• Usage: Commonly found in homes for regulating flow in faucets or showers.
• Advantages: Precise flow control is generally not used as a full shutoff.

Check Valves

• Description: These valves allow flow in one direction and automatically prevent flow in the opposite direction.
• Usage: Often used in sump pump applications to prevent backflow of water.
• Advantages: Automatic function, vital for preventing backflow, which can be damaging or contaminating.

Pressure Reducing Valves

• Description: Adjusts the incoming high-pressure water to a consistent and lower pressure.
• Usage: Installed in homes with high municipal water supply pressure.
• Advantages: Protects plumbing fixtures from excessive pressure, which can cause damage or leaks.

Butterfly Valves

• Description: Uses a disc positioned in the center of the pipe. The disc rotates with the valve stem to control flow.
• Usage: Found in larger plumbing systems, not typically in standard homes.
• Advantages: Compact and can handle large flows of water.

Solenoid Valves

• Description: Electrically operated valves where an electric current controls the flow.
• Usage is often found in sprinkler systems or appliances that need to control water flow automatically.
• Advantages: Quick response time and can be controlled remotely.

Thermostatic Mixing Valves

• Description: Mixes hot and cold water to achieve desired temperature water output.
• Usage: Often used in showers and tubs to prevent scalding and burns.
• Advantages: Provides safety against temperature spikes.

Standard Valves and Specifications

Gate Valve

Gate valves are linear valves having a place with the shutoff valve family. Distinct by its wedge-like circle, the gate valve separates media because it can control the media. This valve is used in applications where tight fixing is needed. A blade gate valve is excellent in thicker and viscous media.

Gate valves give little strain drops since no problem comes in the method of the media stream. The gate works by the gate disc moving upwards to open the valve. It closes by moving the disc downwards to meet with the seats.

Advantages:

• Because the gate within the valve retracts entirely into the body, the valve does not impede water passage.
• Due to the gradual opening and closing of the valve, the water pressure is altered progressively, thereby protecting the pipe from the water hammer noise.

Size

Between Gate Valve and Globe Valve

Globe valves are designed for regulating or throttling flow, offering more precise control with a globe-shaped obstruction in the flow path. Gate valves, on the other hand, are primarily used for on/off flow control, providing a straight-through flow path when fully open.

Pressure Relief Valve (PRV)

A pressure relief valve is a safety valve that automatically releases excess pressure from a system to prevent damage or rupture. It opens when the pressure exceeds a pre-set limit and reseals when the pressure returns to a safe level.

Types

• Direct-acting action pressure release valve
• Electric pressure relief valve
• Balanced pilot-operated pressure relief valve
• Remotely actuated pressure relief valve

Pressure Relief Valve Applications

Cooling and heating circuits

Flows can change a lot when there are irregular loads or when starting up or shutting down. Reactions from boilers or reactors linked to each other can cause the pressure to rise or fall more than the amount that user-controlled equipment (like pumps and heat exchangers) adds. Pressure relief valves help ensure that the pressure in heating systems doesn’t change for no reason.

Systems with sensitive equipment 

Similarly, too much pressure may damage equipment in pneumatic systems with multiple parts. A pressure relief valve may prevent premature failure of the machine and can be part of a scheduled upkeep schedule.

Avoiding cavitation

When the pressure in a liquid drops quickly below the gas pressure, this is called cavitation. If a centrifugal pump works against a closed system, the excess pressure must escape from the pump housing. This makes places with low pressure, which could lead to cavitation. Relief valves avoid the housing by opening when the pressure gets too high. This takes the extra pressure out slowly. And because it keeps the pump from cavitating, it lasts longer.

Selection Standards

Consider the following criteria when purchasing a pressure relief valve. For more information, consult our guide on selecting relief and safety valves.

Body and seal materials: Make sure that the components of the relief valve are well-suited to the media.

The flow of discharge: Make sure that the relief valve is of sufficient capacity to discharge adequately under extreme conditions.

Minimum/maximum operating pressure: Ensure that the relief valve is compatible with the pressure limits of the system.

Adjustable versus non-adjustable: A flexible relief valve is helpful when the intended set pressure is unknown or subject to change over the valve’s lifetime.

Ball Valve

A ball valve uses a spherical closure element (the ball) to control fluid flow. It comprises a hollowed-out ball with a hole or port in the center. The ball has a bore through which the fluid can pass when the valve is open, and it can be rotated within the valve body to block or allow the flow.

Uses

Ball valves provide a full bore for unrestricted flow and minimal pressure drop. They are commonly employed in various industries for on/off and throttling applications, offering reliable shutoff capabilities.

Size

Ball Valve Vs. Gate Valve: What is the Difference

Ball and gate valves work for the same purpose. However, their structural qualities differ significantly. Commonly referred to as “rotational” valves, ball valves consist of a stem and ball that rotates horizontally. Applications need on/off control without pressure drop that best suits these valves.

Gate valves are opened by removing a round or rectangular gate (or wedge) from the fluid’s path. Since the sealing area between the gate and seats is flat, gate valves are frequently used when a fluid stream in a straight line with minimal restriction is required.

Ball Valve Vs. Gate Valve: Which One is Better?

As a result of their design, ball valves can perform an almost instantaneous shutoff, whereas gate valves cannot. This makes ball valves the superior option for rapid cycle speed applications. The 90° operation of ball valves makes them easier to manually and automatically cycle.

Solenoid Valve

Solenoid valves are electromechanical devices that use an electric current to maintain the flow of fluids or gases. It consists of a coil of wire called a solenoid, which generates a magnetic field when an electric current is passed through it. This magnetic field acts upon a movable plunger or valve disc, opening or closing the valve depending on the direction of the current.

How Does the Solenoid Valve Work?

An electromagnetic field is produced by bypassing the electric current through the coil. This electromagnetic field makes the actuator ascend or descend. Solenoid valves use this mechanism to open or close the valve.

Features of Solenoid Valves

• They can be easily integrated into automated systems, allowing for remote operation and control.
• Solenoid valves open and close rapidly, providing quick response times. They are recognized for their reliability and long service life, making them suitable for various applications.

Solenoid Valve Applications

Typical applications for domestic and industrial solenoid valves include:

• Reversing the passageway of refrigerants, solenoid valves are utilized in refrigeration systems. This contributes to chilling in the summer and heating in the winter.
• Automatically controlled solenoid valves are utilized in irrigation systems.
• Solenoid valves control water flow in dishwashers and laundry machines.
• Air conditioning systems regulate air pressure with solenoid valves.
• Medical and dental equipment utilize solenoid valves to regulate the fluid’s flow, direction, and pressure.
• Solenoid valves and a float switch regulate water’s inner flow and outflow in water containers.

Globe Valve

A globe valve controls fluid flow through a disc’s linear motion or plugs against a stationary ring seat. It is known for its spherical shape, which resembles a globe. Here are its advantages, disadvantages, and main applications:

Advantages of Globe Valves:

• Globe valves offer excellent control over the flow rate and can provide precise throttling and regulation of fluid.
• When fully closed, globe valves provide a tight seal, minimizing leakage.

Disadvantages of Globe Valves:

• Globe valves introduce more pressure drop compared to other valve types due to the flow path being diverted around the disc.
• The flow path in a globe valve is not straight, which can result in turbulence and energy losses.
• Globe valves require multiple turns to fully open or close, leading to slower operation than other valve types.

Size

What Is the Primary Difference Between Globe Valve and Ball Valve?

The globe valve has a disc that travels vertically through the valve stem, whereas the ball valve has a hollow ball that rotates within the valve.

Globe Valves Vs. Ball Valves: Which One Is Better?

This depends upon the intended application. Globe valves perform better in applications requiring throttling, whereas ball valves perform better as shutoff valves.

Check Valve

A check valve, a non-return valve, or a one-way valve is a valve that permits fluid to stream in one direction and prevents backflow in the opposite direction. It is designed to open and close based on the flow direction automatically. Here’s some information about check valves:

Working Principle

It consists of a movable disc, called the check valve disc or flap, that opens when the fluid flows in the desired direction and closes to prevent reverse flow. The disc is typically hinged or mounted on a spring mechanism. When the flow is in the correct order, the fluid pushes the disc open against the spring or hinge, allowing it to pass through the valve. However, if there is backflow or reverse flow, the disc is forced back into its closed position, sealing off the valve and preventing the fluid from flowing backward.

Types of Check Valve

• Swing Check Valve
• Spring check valve
• Lift check Valve
• Ball check Valve

Advantages of Check Valves:

• The main aim of a check valve is to stop the backward flow of fluid, ensuring the flow goes in one direction only.
• Check valves operate automatically based on the fluid flow, eliminating the need for external control or actuation.

Disadvantages of Check Valves:

• Check valves introduce a slight pressure drop due to the flow restrictions caused by the disc and seat design.
• Check valves may have limitations on flow capacity compared to other valve types, which can restrict their use in high-flow applications.

Needle Valve

The needle valve is the pressure and flow regulator. Occasionally, it is also called the plunger valve. However, it aids in regulating fluid volume and pressure within the tube lines. This valve’s actuation and change cycle is excellent. Despite this, it provides precise control over the fluid stream. However, the needle valve applies to high pressure and moderate flow rate. The working mechanism is comparable to that of a piston check valve. The only dissimilarity is the size of the piston used in the needle valve, which is smaller.

Material

The needle valve construction

• Bronze
• Stainless steel
• Brass

Nevertheless, the valve seat design of

• CPVC
• PTFE
• PVC

Pressure Rating of Needle Valves

Dimension of Needle Valves

Plug Valve

A plug valve uses a cylindrical or tapered plug to control fluid flow through a pipe or pipeline. The plug has a through-hole or port that can be aligned with the pipe to allow flow or rotated to block the flow. Here are the main features of a plug valve

• Plug valves typically consist of a cylindrical or tapered plug, a body, and an actuator for rotating the plug. The plug can be solid or hollow, depending on the application.
• By rotating the plug, the flow can be fully open, fully closed, or anywhere in between, providing precise flow control capabilities.
• Plug valves have low operating torque due to their streamlined flow path, allowing easy operation even in high-pressure applications.

Plug Valves Applications

It is used in oil and gas, petrochemical, water treatment, and wastewater management. They are well-suited for applications that require on/off control or frequent cycling and can handle abrasive or corrosive fluids.

Pinch Valve

A pinch valve is a kind of valve that controls the flow of fluid by pinching or compressing a flexible tube or sleeve. It is designed to provide a tight shutoff by directly squeezing the tube to stop the flow. Here’s some information about pinch valves and their applications:

How it Works

A pinch valve consists of a housing or body, a flexible tube or sleeve, and a mechanism to pinch or compress the tube. When the valve opens, the tube is uncompressed, allowing fluid flow. To close the valve, the mechanism pinches or compresses the tube, effectively shutting off the flow.

Applications of Pinch Valves:

• Pinch valves are commonly used in industries that handle slurries, such as mining and chemical processing. They effectively control the flow of abrasive or solid-laden fluids without clogging or damaging the valve.
• It is employed in the oil and gas industry to maintain the flow of corrosive or abrasive fluids, including drilling muds, slurries, and crude oil.

Advantages

The distinctive design of pinch valves affords them the following benefits:

• Excellent for use with corrosive and abrasive media
• Protects media from contamination
• Simple replacement and minimal maintenance costs
• Outstanding sealing properties
• Rapid opening and closing duration

Disadvantages

There are a few disadvantages to pinch valves:

• Due to the elastomeric nature of the pinch valve sleeve, the valve cannot be used in high-temperature environments.
• High-pressure differentials can cause the rubber sheath to collapse or deform, preventing the valve from opening completely.
• The valve is inappropriate for vacuum applications because internal suction may cause the sleeve to collapse.

Angle Valve

An angle valve has an angled body, typically at a 90-degree angle, with an inlet and an outlet forming an “L” shape. It is also known as a corner valve or angle stop valve. Angle valves are commonly used to control water flow in plumbing systems. Here are some key features and applications of angle valves:

Features of Angle Valves

• Angle valves have a 90-degree bend in their body, allowing the inlet and outlet to be at right angles to each other. This design makes them suitable for installations in tight spaces or at corners.
• Angle valves are available with compression or threaded connections, allowing them to be connected to pipes or fittings using appropriate adapters or couplings.

Why do we use Angle valves?

If you are upgrading or renewing your faucet or other fixtures in your home, or if you need to repair them, you can use the angle stop valve to close off the water to the devices or fixture that requires repair rather than turning off the water to the entire plumbing system.

During a water leak or even a complete pipe burst, you can use the angle stop to turn off the primary water supply to the appliance or fixture until necessary repairs are made.

Material Variety

Copper is considered the best material for angle valves. Yet, It has a longer lifespan and provides superior service. Zinc alloy is susceptible to oxidation and has a reduced service life compared to copper. Plastic or PVC is not attractive and has a reduced lifespan. In addition, metal alloys have an improved sheen and luster.

Angle Valves Applications at Home

Generally, four locations in the home require angle stop valves: the cold water angle stop valve on the toilet water nozzle, the cold and hot angle stop valves on the wash basin and wash basin on the nozzle, the cold and hot angle stop valves on the sump on the sink, and the two cold valves on the water heater on the water nozzle. In addition, if a water purifier is present, an angle valve for cold water must be installed.

Technical Data

• Size: 3/8 inches, ¾ inches, ½ inches
• Thread Connection: NPT, BSPT, BSP
• Working Pressure: 12 bar
• Temperature: -10 ˚C-100˚C

Buying Guide to Valves

Application: Determine the specific application and the conditions in which the valve will be used. Consider factors such as the kind of fluid (liquid, gas, or slurry), temperature, pressure, flow rate, and any special requirements or environmental considerations.

Material of Construction: Consider the compatibility of the valve materials with the fluid being handled. Valves are accessible in different materials such as brass, stainless steel, cast iron, PVC, and exotic alloys. Ensure the materials suit the fluid’s chemical composition, temperature, and pressure.

Valve Type: Select the appropriate valve type based on the application requirements. Common types include ball valves, gate valves, check valves, globe valves, butterfly valves, and plug valves. Each class has advantages and limitations, so choose one that suits your needs.

Size and Connection: Determine the required valve size based on the pipe or system specifications. Consider the connection type, such as threaded, flanged, or welded, and ensure it matches the existing piping or fittings.

Standards and Certifications: Check if the valve meets relevant industry standards and certifications, such as ANSI, API, ISO, or specific safety or regulatory requirements for your application.

Sealing and Leakage: Evaluate the valve’s sealing mechanism and capacity to give a tight seal when closed. Consider factors such as leakage rates, sealing materials, and the valve’s ability to prevent backflow or leakage in both directions.

Material for Manufacturing the Valves

Here are some commonly used materials for valve construction and their typical applications:

• Stainless Steel
• Brass
• Cast Iron
• Bronze
• Carbon Steel

Conclusion

Knowing the various household valves and their functions can give homeowners a better understanding of their plumbing system. This knowledge is invaluable, especially when troubleshooting issues or planning renovations. While some valves offer a simple open-close mechanism, others play pivotal roles in safety, conservation, and appliance protection.

A valve is a very useful device for different applications. It controls, regulates, and directs the stream of liquids and gases in the pipe by opening, closing, or partially opening the passageways for the pipeline stream. There are many types of valves, and every valve has its application. Valves are used for different purposes, including residential, industrial, agriculture, transport, mining, power, oil and gas, and all sectors.