A valve works by regulating and controlling the flow of liquids within a process. This is the primary step where there is a direct flow of liquid. Various characteristics of valves can help determine the ideal application.

People always look to control the flow to give safety to the system. Whether you are piping liquids, gases, or solids, or any other thing, stainless steel valves are always helpful with several benefits.

There are different methods of valve opening. However, they usually differ mechanically. The closing and opening of the valves do not directly impact the overall performance of the valve system. However, it usually enquires how much control is there on the flow and how quickly the valves can operate.

Here are the valve functions:

• The valve can be used to start or stop flow based on its state.
• Within a piping system, it is regulating flow and pressure.
• A pipe system can be redirected to flow in the correct direction.
• It is possible to lower the flow rate of fluid in a piping system.
• By relieving pressure or vacuum, piping systems can be made safer.

Types of material used in valves:  Download Valve Material Specifications

The materials from which the industrial values are made are very much important things to consider. It depends on your intended use that the materials for valves must ensure safe operations. High-quality material will ultimately result in less maintenance and a lower replacement cost over its life.

Stainless steel is the best material to be used as it gives you different options in a range of processing environments. Stainless steel material is an incredible one in competing for corrosive media such as acid, saltwater, or chemicals.

In some environments that require strict sanitation standards, such as food and beverage industries and pharmaceutical industries, stainless steel valves are also widely used. Stainless steel is also the best option in those processes which involve high temperatures and high pressures.

However, to process different solvents, fuels, volatile organic compounds, you can also use non-sparking material such as bronze, brass, copper, or even plastic materials.

Chemical compatibility of internal trim parts should be considered, along with choosing the suitable body material. You must reject chemical compatibility if the valves contain elastomer. You must also limit pressure and temperature limitations to account for those industrial valves.

Here we will introduce the valve types, pros and cons of different types of valves, and valve applications.

1. Ball valve

A ball valve uses a ball-shaped disk to stop or start fluid flow. It is part of the quarter-turn valve family. The ball valve is usually equipped with 90-degree turn handles, which are very fast.

Advantages

• Great shut off/on capability
• Minimal leakage through wear and tear if properly used
• Low maintenance cost
• Minimal pressure drop
• Time and labour effective to operate

Disadvantages

• Not suitable as control or throttling valve
• Not suitable for thicker media as sedimentation could occur and damage the valve disc and seat
• Surge pressure can occur due to rapid opening and closing

Applications

Ball valves are made for fluid, gaseous, and vapor applications that need bubble-tight closing. They are primarily designed for low-pressure uses; high pressure and high-temperature applications will apply to ball valves with metal seats.

2. Butterfly valve

A butterfly valve is used to stop, regulate, and start fluid flow. They are easily and quickly operated because a 90° rotation of the handle moves the disk from a fully closed to a fully opened position. They are also part of the quarter-turn valve family. It has a concave disc attached to the valve system, distinct from the other valves.

Advantages

• Compact design
• Lightweight
• Minimal pressure drop
• Easy to install

Disadvantages

•  Limited throttling capabilities
• Strong pressure may affect disc movement

Applications

Butterfly valves are used in water and gas applications where there is a need to isolate or interrupt media flow. They are perfect for processes that use large diameter pipes. They can also handle slurries, cryogenic, and vacuum services.

3. Check valve

Check valves prevent the reverse flow in a piping system. The flowing material in the pipeline activates these valves. The pressure of flowing fluid opens the valve while any reversal of flow will close the valve. They rely on internal pressure for opening and closing rather than the outside action. Prevention of backflow is the main purpose of this valve.

Advantages

• Simple design
• No need for human intervention
• Effectively prevent backflow.
• It can be used as a backup system.

Disadvantages

• Not suitable for throttling
• The disc may potentially stick in the opening position

Applications

Check valves are used in appliances that need backflow prevention, such as pumps and compressors. Feed pumps also use check valves. Chemical and power plants have numerous processes that use check valves. They are also used when there is a combination of gases in one pipeline.

4. Gate valve

Gate valve is the linear motion valve used to start or stop fluid flow. It does not regulate or throttle flow. The valve gets its name from the appearance of the disk inflow system. Gate valve is a member of the shut-off/on valve family. This valve is primarily suited for isolation.

Advantages

• No media flow resistance because gate does not obstruct flow hen fully opened.
• It can be used as bi-directional flows
• Simple design
• Suitable for pipes with large diameter

Disadvantages

• Not good for throttle
• The intensity of media flow can damage the gate or disc when used for throttling.

Applications

Gate valves are great valves for any shut-off/on applications. They are suitable for wastewater and neutral liquid applications. They can endure – 200C and 700C with a maximum 16 bar pressure, so the applications with temperature and pressure within this range can use gate valves. Typical uses of knife gate valves are in slurries and powder media.

5. Globe valve

A globe valve is used to regulate, start, and stop fluid flow. The perpendicular movement of the disk from the seat is the essential principle of the globe valve. This causes the ring shape space between the disk and seat ring to close as the valve is closed. The Globe valve looks like a globe with plug type disc. Globe valves come in three types of body, including the Y-pattern, the T-body, and the angle body.

Advantages

• Better shutting mechanism compared to gate valve.
• Wear and tear is not an issue even with long-term use
• Easy to repair

Disadvantages

• Not great for high-pressure applications
• The high-pressure loss could occur from obstructions of the media flow path

Applications

Globe valves work perfectly when there is a need to prevent leakage. High point vents, low point drains, cooling water systems, feedwater systems, chemical feed systems, extraction drain systems all use globe valves.

6. Needle valves

As the name depicts, needle valves are typically used in small diameter piping systems. They are required in situations where accurate flow control is needed. They get their name from the narrow point in the conical disc used within.

7. Pinch Valve

Slurries, liquids containing suspended solids, or solids in suspension are handled by pinch valves. While flowing, linear motion is used in these pinch valves. Additionally, these valves contain internal sleeves that isolate the media.

8. Plug valve

Typically, plug valves control the flow of fluid by utilizing cylindrical or tapered plugs. To maintain the flow, they use a quick-acting quarter-turn valve handle. They are mainly famous for giving tight shutoff and also very effective in high-temperature or high-pressure environments.

9. Pressure Relief Valve

As the name depicts, pressure relief valves are used in those areas where there are overpressure events. So they are accommodating in increasing safety by using automated spring valves. By decreasing the pressure, they will therefore return the system to the desired pressure.

Valve Classification (by Functions)

• Isolation valves

There are many types of valves in isolation valves, such as pinch valves, Gate valves, diaphragm valves, ball valves, butterfly valves, Piston valves, and plug valves.

• Regulation valves

Regulation valves include diaphragm valve, needle valve, Ball valve, butterfly valve, globe valves, pinch valves, and plug valves.

• Safety relief valves

Safety relief valves include vacuum relief valves and pressure relief valves.

• Non-return valves

Check valves for lifting and swinging are among them.

• Special purpose valves

These include float valves, foot valves, multiport valves, the line behind the valve, and the knife Gate valve.

An industrial valve is an essential part of the industrial system. Every pipeline is incomplete without valves. The safety and lifetime service of the pipeline process depends on the quality of industrial valves. So, it is pivotal for an industrial valve manufacturer to deliver high-quality valves. But how to make a high-functioning industrial valve? What is the secret of a good quality industrial valve? Does the performance of the industrial valve depend on its material? You need to understand the manufacturing process of industrial valves to know how good quality valves can be made.

What are industrial valves?

A valve is a device or an object that regulates, directs, or governs the flow of fluids by opening, shutting, or partially obstructing passageways. Valves are mechanical devices that manage the fluid’s flow and pressure. Industrial valves are designed to handle high pressures of liquids or gases, and they can last years in this harsh environment. Any piping system will not survive without a valve. So now you know the importance of industrial valves, let’s dig into their processing and production process.

Industrial Valve Manufacturing Process

Before starting the manufacturing process, you have to determine the type of industrial valve you want to make. You should know customer’s demand and manufacture industrial valve according to it. The valve or its raw materials have to undergo various processes. Here is the complete series of procedures.

Order and design of industrial valve

First, you need to get an order from a customer. Ask the customer what type of valve he needs and in which appliance he will use the valve. You can show the customer the list of already available designs. A customer can pick a design from that list or demands a customized design. After the selection of design, the sales representative puts order and notify the company. The customer will also provide the company with a pre-defined deposit.

Inventory

A single industrial valve has various parts. Following are the main parts of an industrial valve.

1. Stem
2. Body
3. Spool
4. Bonnet
5. Actuator
6. Valve trim
7. Valve member

The company will gather all the raw materials required to produce various parts of an industrial valve. If there is insufficient material present in the company’s inventory, the industrial valve company will contact the supplier and demand the material.

Checking the checklist

Once you have all the materials, the manufacturing team will go over the list again to make sure all materials are present. At this point, the approval of the final draft of the design also happens. Moreover, the management team will call the quality assurance team to ensure that all the raw materials are top-quality.

Production process

The majority of the procedures occur in this process. The raw materials will undergo different phases to give the final shape of the industrial valve. All the major components of industrial valves will be made individually. Some companies have a checklist at this point also. The list entails all the names of the spare parts and the raw material to use for each piece.

The team leader will provide the company with the paperwork for the actual manufacturing, from the start of the manufacturing to the completion date of the production process. Commonly, there are two important methods of industrial valve manufacturing.

1: Cast method

The casting method uses the liquid form of metal to create industrial valves. The metal from the raw material is melted at high heat and then poured into the mold. This metal is allowed to cool and solidifies, and once the metal cools and hardens, we will eject it from the mold. Here is a detailed description of the whole process.

• Body

The initial pre-shaped material is cleaned before the turning process. Turning is the process of removing surplus material from the mold by cutting away the unwanted material. You have to attach the pre-shaped body to the amount and turning machine. The machine rotates at high speed. During rotation, it cuts the body into a desired and specific shape.

In the next step, a plating metal, usually copper, is added to the different sections of the body. Copper plating ensures proper and complete sealing of the body. After the plating is done, the body will undergo polishing. After it, the technician will attach the body to other parts of the valve. Valves need holes for this purpose, so the holing is done at this point. This is because each industrial valve has a unique hole size depending upon the requirements.

After this step, workers paint the industrial valves with Teflon or any other elastomer. Baking of the valve follows its painting. Teflon binds with the body during baking.

• Seat

The same process used to manufacture the body is used for the manufacturing of seats. But the seat needs better sealing and perfect attachment because it is mostly present inside the body. For this purpose, the seat has rubber wrapping in addition to the Teflon to ensure tight fitness.

• Stem

The manufacturing of stem is not very detailed. Only cutters are used to cut the material in the right dimensions for stem manufacturing.

2: Forged method

As the name suggests, the solid metals are forged to make the valve. Here are the highlights of the forged method.

• Cutting and forging

Firstly, select the right raw material. In the next step, cut the material into desired length and width. After this, the next step is to forge the material by slightly heating them to a certain degree.

• Trimming

The next step is trimming after cutting and forging. Here, the excess material is removed, and the body is flashed to mould it in the right industrial valve shape.

• Sandblasting

Sandblasting is the next step after trimming. Examine the industrial valves and remove the defective ones. Sandblasting is done to make ample valves smooth and clean. The size of the sand particles used depends upon the customer’s requirements or standards.

• Machining

Machining is done to enhance further the sizes and shapes of threads and holes. It ensures whether the product reaches its standard quality or not.

• Surface treatment

The industrial valve undergoes some treatment of the surface by the use of acid or alike. This ensures that the valve will not harm the environment in any way.

Assembly

Assembly is the step where all spare parts of the valve are aligned to give the final shape to the industrial valve.

Pressure test

As the name suggests, the pressure test valve has to undergo actual high-pressure testing for leakage. In some instances, air with 6 to 8 bar pressure fills the closed valve for a certain number of hours. If the leakage is reported after some time of testing, the company will repair the valve. If there is no leakage, it will move onto the next phase. The same test can also be done by use of water pressure.

Inspection and quality control

In this step, the quality assurance team will inspect the valve for any leakage or production error. If no defect is found, the industrial valve will move further into the line.

Packaging and transportation

The finished industrial valve is packed and sent to the warehouse for delivery.

Conclusion

The manufacturing of an industrial valve is a complex process. It is not just a simple creation of valves. Many factors contribute to its efficiency and quality. All the steps mentioned above are needed to perform professionally to produce a good quality valve. Moreover, industrial valves should undergo rigorous testing before handing them over to the customer. If during testing, industrial valves started to leak, then they should not be delivered to the customer. If there is internal leakage in the valve during testing, the manufacturing methods employed are not within the standard.

DBV is a leading industrial valve manufacturer and supplier in China, we can manufacturer industrial-grade butterfly, ball, gate, globe, check, plug valves with the highest standards in different countries.

Usually, the working fluid’s pressure and temperature are the two main factors on which the choice of end connections depends. They form the relationship between the valve and its pipework. Moreover, it is dependent upon the frequency of the removal of the valve from the pipeline. Following are the types of end connections in general use.

1. Screwed

In screwed-end valves, female pipe threads are common, although male threads are helpful for other purposes. Tapered female threads on these pipes make them suitable for joining together taper threaded pipes. It also connects parallel to tapered or parallel threaded pipes for assembly.

The pressure-tight Joint is very much necessary for tight connections. Pressure-tight connections are made for this purpose on threads for taper-to-taper connections and parallel taper connections. In parallel-to-parallel connections, a gasket or grommet is compressed against the valve’s end face to ensure that the joint is pressurized.

Keep in mind that screwed ends are widely used for bronze valves. They are also used for Iron and Steel valves but to a smaller extent. Screwed ends are usually connected to pipe sizes of 150 mm or smaller.

2. Flanged

These individuals are straightforward to install and also easier to remove from the pipeline. Flanged-end-valves are then bolted to the mating pipe flanges. Gaskets are usually used to ensure tight sealing between the machined facing of the flanges. Keep in mind that gaskets are of different types, such as non-metallic, metallic, or the combination of metallic and non-metallic.

Typically, the gasket type varies with service conditions and flange facing employed. Valve components made of bronze and iron are generally supplied with plain facings (flat facings). Stainless steel valves are available plain, raised, or male-faced. Female, tongue-and-groove, and ring-joint types of joints are also available. An end valve with a flanged tip can be manufactured up to 15mm in diameter.

3. Socket-weld

This type is equipped with sockets at the ends, which receive plain-ended pipe. Our circumferential welding keeps weld spatter and ‘icicles’ from entering the pipeline. We are only permitted to use socket weld on steel valves. Their size is also limited to 50 mm and smaller. So these are used for high pressure-temperature applications in Pipelines that do not require frequent dismantling.

4. Butt-weld

As seen in this case, the valve’s edges match the wall thickness, leaving a machinable bevel on the end of a matching pipe. An adjacent mating bevel has a circumferential weld. We now need to figure out just what the backing rings are. It consists of sleeves attached to the pipe.

In alignment with the pipe, these backing rings serve as securing devices. Pipeline valve bores to ensure that weld spatters and icicles cannot enter the pipeline. Butt-weld ends are primarily used on steel valves of size 50 mm or above. They are usually used for high pressure-temperature applications in those pipelines which do not need any frequent dismantling.

5. Compression

The socket in this type of valve end receives the pipe and is plugged with a union nut. The compression makes this Joint of a ring or sleeve outside the plain end pipe.

However, the Joint also compressed a performed portion of the pipe end. In general, compression ends are used with copper tubing and steel tubing up to 65mm in diameter. In low-pressure situations or those where a pipe may have to be frequently dismantled, they can be used.

6. Capillary

This valve is connected to a pipe by soldering. A socket is machined into the end of the valve to accept a plain-end pipe. An annular space creates the capillary path for the solder flow between the socket and the pipe’s outside.

Copper tubing ends are typically used with capillary ends that are 65mm and smaller. Because capillary end valves have low melting points, their use at high temperatures is inherently limited.

7. Socket

An end of the valve has a receptacle that receives a plain spigot end of the pipe. The embedding makes this seal of around yarn ring and its intersection with a lead cork. Another type of socket end uses a rubber ring to facilitate cleaning.

These ends are either flanged, or socket ends for bolting to flanged ends of valves. A valve can have them incorporated into it. Cast iron valves typically have socket ends, which come in sizes 50mm and upwards.

8. Spigot

Different couplings have different types of sockets that determine how the spigot ends appear. An elevated band is provided on the end of lead joints in cast iron pipe. The end of the spigot is prepared to suit the joint for screwed and bolted glands and other mechanical joints.

The spigot end of an asbestos cement connection is finished plain in a similar way as the pipe. Typically, the ends of cast iron valves are attached to water spigots in the 50mm and up range.

There are different methods of valve opening. However, they usually differ mechanically. The closing and opening of the valves do not directly impact the overall performance of the valve system. However, it usually enquires how much control is there on the flow and how quickly the valves can operate.

Mostly the valves fit into one of the two categories:

• Multi-turn valves

Think about these valves as if they were screws or pistons. By cranking the handle, you control the plug, plate, membrane, or other control obstruction. It prevents access to the pipe. These pipes have broader or narrower differentials, depending on the valve. They are then able to be opened or closed at various speeds.

• Quarter turn valves:

It is effortless to get the full range of motion with a 90-degree turn of the angle with the help of a quarter-turn valve. Consequently, they are ideal for rapid action situations where precision might not be as important. Furthermore, it facilitates opening or closing.

In addition to the mechanical movement involved in the valve, the valve actuation method must also be considered. Valves are usually divided into three categories in most cases.

• Manual valve

Manual valves are usually controlled by the hand, where they use hand levels, handwheels, chains, or gear wheels to actuate.

• Actuated Valves

They are usually attached to electric motors or air or pneumatic systems. They also connect to solenoids or hydraulic systems. Actuated valves are generally used in large-scale applications where high precision is required. It can be possible with the help of automation or remote control.

• Automatic Valves

When the particular flow condition is met, then automatic valves are activated. Check valves are an example of automatic valves. These check valves are usually closed during backflow. Others are pressure release valves which activate when an over-pressure situation is detected.

Your valves might have to meet particular standards depending on your intended use. Those standards are maintained to meet the regulatory requirements of safety, health, and sanitation. Besides, there are many standard organizations and potential regulations to meet the criteria.

ASME B31.1:

• ASME B16.34, valve: flange, thread, and weld end
• MSS SP67- Butterfly valves
• MSS SP68 high-pressure butterfly valve with offset design

ASME B31.3:

• ASME B16.34, valves-flanged, threaded, and welded
• MSS SP72-flanged or welded ball valves for general services
• API 608-with flanges, threads, and butt-welded ends Metal ball valve
• API 6D: Pipeline and Piping Valve Specification

ASME B31.4:

• ASME B16.34, Threaded, Valves–Flanged, and Welding End
• MSS SP68–High-Pressure Butterfly Valves with Offset Design
• MSS SP72–Ball Valves with Flanged or Butt-Welding Ends for General Service
• API 600–Steel Gate Valves-Flanged and Butt-Welding Ends, Bolted Bonnets, Twelfth Edition
• API 602–Steel Gate, Globe and Check Valves for Sizes DN 100 and Smaller for the Petroleum and Natural Gas Industries
• API 603–Corrosion-resistant, Bolted Bonnet Gate Valves-Flanged and Butt-Welding Ends
• API 6D–Specification for Pipeline and Piping Valves
• API 6A–Specification for Wellhead and Christmas Tree Equipment

ASME B31.8:

• ASME B16.33–Manually Operated Metallic Gas Valves for Use in Gas pipeline Systems up to 175 psi (Sizes NPS1/2 Through NPS 2);
• ASME B16.34 Valves–Flanged, Threaded and Welding End;
• ASME B16.38–Large Metallic Control Valves for Gas Distribution: Manually Operated, NPS 21 .2 (DN 65) to NPS 12 (DN 300), 125 psi (8.6 bar) Maximum;
• API 6D–Specification for Pipeline and Piping Valves;
• API 6A–Specification for Wellhead and Christmas Tree Equipment.