Trusted Plug Valve Manufacturer
NTVAL provides durable Plug Valves for heavy-duty industrial applications. Known for tight sealing, easy maintenance, and reliable performance, our precision-engineered valves excel in demanding environments. Choose NTVAL for strength, efficiency, and long-lasting service.
Reliable Plug Valve
Plug valves are valves that use cylindrical “plugs” to control the flow of fluid. These plugs can be rotated inside the valve body to either allow or block the flow. The plugs have one or more hollow passageways running sideways, enabling fluid to pass through when the plug is in the open position.
Quality Control
Plug valves undergo a PMI test to confirm metal composition, ensuring each valve meets exact specifications. This step helps prevent contamination risks.
PMI Test
The sealing test checks each plug valve for leaks under pressure. This quality control step keeps the valve reliable for controlling fluid flow.
Sealing Test
A low emission test verifies that plug valves release minimal emissions. This test makes them a safer choice for environmentally-sensitive applications.
Low Emission Test
During the impact test, plug valves are tested for strength. This process checks their durability, making them resilient under harsh working conditions.
Impact Test
Dimension inspection ensures plug valves match specified sizes. Accurate sizing supports proper fit and functionality, essential for consistent performance in pipelines.
Dimension Inspection
The painting thickness test verifies protective coating levels. A thick enough coating protects the plug valve against rust and environmental damage.
Painting Thickness Test
PT testing detects surface cracks in plug valves. This step ensures smooth operation by identifying any flaws that could weaken the valve.
PT
Material inspection confirms the plug valve’s materials meet quality standards. It guarantees each valve’s durability and compatibility with different industrial applications.
Material Inspection
Our Valve Applications in Key Industries
Discover how our advanced valve solutions improve flow control, delivering enhanced efficiency, safety, and strict quality assurance.
A plug valve offers reliable flow control, making it ideal for the chemical industry. Its simple design prevents leaks, which is crucial when managing corrosive or hazardous substances.
Chemical Processing
In petrochemical operations, plug valves handle high pressures and temperatures with ease. This makes them suitable for managing volatile fluids and gases effectively.
Petrol Chemical
Plug valves work well in O.P.G. and nuclear applications, providing consistent, safe flow management. Their durability supports safety in these high-stakes environments.
O.P.G & Nuclear
Plug valves resist pulp buildup and can control thick fluids easily. They maintain steady flow, critical in handling viscous substances common in pulp processing.
Pulp
Mining operations require durable valves, and plug valves meet the demand. Their strength and resilience make them suitable for abrasive slurries and harsh conditions.
Mining
Plug valves provide effective flow control for water and sewage systems. Their straightforward design minimizes blockages, ensuring smooth and continuous operations without leaks.
Water & Sewage
In steam systems, plug valves manage high temperatures efficiently. Their secure sealing capabilities make them essential for controlling steam flow without risking leaks.
Steam System
Plug valves perform well in boiling systems, where heat is intense. They withstand temperature variations, ensuring stable, safe operation through reliable flow control.
Boiling System
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All You Need to Know About Plug Valves
Considered one of the oldest types of valves, plug valves are also known as cock or stop cock valves. They belong to the rotary control valve family and are often classified as quarter-turn valves.
As the name suggests, plug valves have a disc shaped like a plug. While they are primarily used as isolation valves, they can also function as throttle valves, though they are better suited for isolation purposes.
What Are Plug Valves Used For?
Plug valves are widely used across commercial, industrial, and light applications for reliable flow control. They handle both corrosive and neutral liquids, steam, gas, and liquid fuels, as well as fluids with suspended solids like slurries. Their design makes them ideal for low-pressure, low-temperature services, ensuring smooth, leak-tight performance with minimal flow resistance. Plug valves are also available in multi-port configurations, supporting multi-directional flow and simplifying inline maintenance. These qualities make them versatile solutions across various systems and sectors.
Plug Valve Parts
Plug valves have the typical components found in most valves, including the stem, body, disc, and bonnet. What sets plug valves apart is their unique plug disc design.
Another distinctive feature of plug valves is the absence of a bonnet or packing. Typically, the plug is directly connected to a short stem, which is then linked to the handle or actuator. Often, the upper end of the disc and the handle are exposed, making them easily accessible.
The Plug Valve Body
The valve body encloses all the internal components of the valve and connects directly to the pipes through a specific end connection.
The Plug Valve Stem
The stem links the disc to the handle or actuator, transferring the movement from the actuator to the plug disc. This action causes the plug disc to open or close. In a plug valve, a short stem connects directly to the disc.
The Plug Valve Disc
The plug disc in a plug valve is a tapered piece that serves as the plug, setting it apart from other valves like the globe valve. While plug valves, ball valves, and globe valves share some similarities, the key difference lies in the design of the disc. In a globe valve, the disc is cylindrical, whereas, in a plug valve, it is a solid metal piece with tapered ends that fit into grease grooves at the bottom of the valve.
The plug disc also shares some resemblance with the ball valve disc, as both are hollow. A quarter turn of the plug disc allows the media to flow through the valve, and turning it in the opposite direction closes it, blocking the flow. This opening and closing mechanism is similar to that of a ball valve.
Plug discs have ports, which are openings in the disc that allow media to pass through. The most common plug discs have two ports located on opposite ends of the disc. When the plug disc is turned a quarter turn, it opens the ports and allows the media to flow through. Turning the disc another quarter turn in the opposite direction closes the ports, stopping the flow of media, much like the operation of a ball valve.
Plug Valve Port
Plug ports are the openings in the solid plug disc of a plug valve. When the port is open, it allows media to flow through; when it’s closed, it blocks the passage of the media. There are three main types of plug ports:
The Diamond Port
The diamond-shaped port, one of three plug port types, is ideal for throttling. Its design creates a Venturi effect, reducing fluid pressure as it passes through the constricted section, making it effective for controlling flow rates.
The Rectangular Port
The rectangular port is the most common type of plug valve port. It typically covers at least 70% of the cross-sectional area of the plug disc, allowing a substantial flow of media through the valve.
The Round Port
A round port matches the pipe’s diameter for unrestricted flow, ideal when full flow is essential. A reduced port has a smaller diameter, allowing minor restriction, suitable for applications where it’s not a concern.
Types of Plug Valves
Plug valves are available in either lubricated or non-lubricated designs. The options become even more varied when considering the different types of ports that can be incorporated into these designs.
Non-Lubricated Plug Valve
Non-lubricated valves do not rely on lubrication for protection. Instead, they are designed with different features or materials to minimize friction and wear. There are three sub-types of non-lubricated valves, each categorized based on its design or the material used.
Elastomer Sleeved Non-Lubricated Plug Valve
Some non-lubricated plug valves use an elastomeric sleeve to protect the valve components. This sleeve is non-metallic and also serves as an additional sealant for the valve. When the plug disc pushes against the sleeve, it creates a tight seal.
Lift Type Non-Lubricated Valve
This type of non-lubricated valve utilizes a spring or lever mechanism to mechanically lift the plug, unsealing it from the valve seat. In other designs, line pressure is used to unseat the plug from the valve seat. These features help to reduce friction and make it easier to operate the valve.
Lubricated Plug Valve
Friction in metal valves can cause leaks, especially at the packing, stem, and disc. Lubricated plug valves reduce friction to prevent the disc from sticking and extend valve life. Grooves in the disc channel lubricant from an injection pump, while a chamber catches excess, and a check valve prevents backflow.
Ideal for high-pressure applications, these valves resist corrosion, though contamination risks require compatible lubricants. Regular maintenance ensures reliable performance and long service life, making them a dependable choice for demanding conditions.
Fully-Lined Non-Lubricated Plug Valve
Fully-lined plug valves have both the plug disc and the valve body covered with an elastomeric material, often Teflon. Other materials used for lining include perfluoroalkoxy copolymer resin (PFA) or tetrafluoroethylene (TFE).
The full lining provides enhanced resistance to corrosion, making the valve more durable and suitable for handling aggressive chemicals. The valve body is typically made of iron, offering structural strength, while this design is particularly well-suited for vacuum services and applications requiring minimal contamination.
Eccentric Plug Valve
Design and Function
Eccentric plug valves have a unique design where the plug disc is cut in half. This design improves the valve’s ability to tightly seal, reducing friction when opening and closing, which makes the valve easier to operate, more efficient, longer-lasting, and low-maintenance.
NTVAL eccentric plug valves are versatile and suitable for both isolation/shutoff and throttling/control services. They are capable of handling a wide range of fluids, including:
- Clean and dirty liquids
- Sludge
- Slurries
- Gases
- Viscous and abrasive materials
Plug and Seat Options
- Resilient Plug Facings: Provide drip-tight, bi-directional shutoff.
- Metal Plugs: Offer shutoff according to ANSI/FCI 70-2 Class IV standards.
- Welded Nickel Seat: Protects against corrosion and prevents damage to the plug face, ensuring a reliable seal.
- Raised Seat Design: Pushes solids away to improve closure reliability.
Size and Temperature Range
These valves come in a variety of sizes, ranging from 0.5 to 72 inches (15-1800 mm), and can operate in temperatures up to 300°F (150°C).
Pressure Ratings
- Cast Iron Valves: Rated to 175 psi CWP for sizes 0.5 to 12 inches, and 150 psi for sizes 14 inches and larger.
- Ductile Iron Valves: Rated to 285 psi for sizes 12 inches and smaller, and 250 psi for sizes 14 inches and larger.
- Special NTVAL valves are available for pressures up to 450 psi CWP.
Applications
Eccentric plug valves are used in a variety of industries, including:
- Water and wastewater (sewage) treatment
- Pulp and paper
- Chemical and petrochemical processing
- Power generation
- Mining
- Steel production
- Other process industries
3-Way and 4-Way Plug Valves
Design and Function
- Designed for throttling and diverting fluid flow
- Feature a multiple-port design
- Available with single or double-tapered plug styles
- Allow for flexible flow combinations
- Provide reliable operation in both on/off and flow control applications
Size and Pressure Ratings
- Available in sizes ranging from 3 to 16 inches
- Pressure-rated to 125 psi CWP
- Temperature tolerance up to 400°F
- Suitable for both low and high-pressure systems
- Compatible with various industrial fluid applications
Material Options
Standard body materials include:
- Cast Iron
- Aluminum
- Carbon Steel
- 316 Stainless Steel
Plug and Seat Options
- Resilient-Seated Plugs: For applications requiring dead-tight shutoff, resilient-seated plugs are available. These can be operated using either a lever or double-handwheel actuator.
- All-Metal Plugs: For high-temperature applications where a dead-tight shutoff is not required, all-metal plugs are an option.
Applications
3-way and 4-way plug valves are versatile and can handle a wide range of media, including:
- Clean and dirty liquids
- Viscous and corrosive fluids
- Sludge
- Abrasive and fibrous slurries
- Clean and dirty gases
Pump Check Valves
Pump check valves are designed to protect pumps from issues like water hammer, reverse flow, and backspin in pump flow control systems. NTVAL Pump Check Valves carefully manage the opening and closing speeds, preventing pressure surges and ensuring smooth operation.
Key Features
- Prevents Water Hammer: Controls valve movement to avoid sudden pressure surges.
- Prevents Reverse Flow and Backspin: Ensures that fluid does not flow backward, protecting the pump.
- Custom Designs: NTVAL offers custom PEC or PEF Eccentric Plug Valves and BAW AWWA Butterfly Valves tailored for specific pump control needs.
Applications
NTVAL Pump Check Valves are ideal for:
- Municipal Installations: Especially effective in systems with long pipelines, hilly terrains, or significant elevation changes.
- Industrial Process Systems: Commonly used in primary cooling towers for power generation and other industrial applications where pump protection is essential.
Balancing Valves for HVAC
Balancing valves are crucial components in heating and air conditioning systems, particularly in multi-story commercial buildings. They allow precise control and measurement of flow in condenser, hot water, or chilled water systems, ensuring the desired flow rate, balance point, and temperature are maintained throughout the building.
½” – 2” Plug Valve Design
- Available in sizes from 1 to 24 inches (25 to 600 mm).
- Uses the proven PEC Eccentric Plug Valve design.
- Equipped with upstream and downstream flow taps for easy flow measurement and optimal valve positioning.
Body:
- Material: ASTM A536 65-45-12 ductile iron with high-pressure molding techniques.
- Connection Options: Threaded connections for sizes ½” to 2″; flanged connections for 2″ size.
- Standards: Flange dimensions conform to ANSI B16.1 Class 125 standards.
Seat:
- Material: Corrosion- and abrasion-resistant epoxy coating for long-lasting durability.
Plug:
- Design: Encapsulated with elastomers molded to the casting, supported on integral trunnions.
- Sealing: Abrasion-resistant elastomers provide tight shut-off, even under vacuum conditions, and prevent abrasive materials from entering the bearings.
Expanding Plug Valve
Expanding plug valves are ideal for applications where avoiding contamination is critical. These valves feature a unique mechanical expansion mechanism, similar to a block-and-bleed manifold, isolating the media from the upstream side and preventing it from reaching downstream components.
Key Features
- Dual Seating Surfaces: In the closed position, the valve uses two seating surfaces to block both ends, ensuring effective isolation and preventing any flow through the valve.
- Contamination Prevention: The design keeps media isolated, making these valves perfect for systems where contamination must be strictly avoided.
- Mechanical Expansion Mechanism: Ensures reliable sealing and isolation by expanding the plug inside the valve body.
- Ideal for Critical Applications: Suitable for industries requiring strict contamination control and system integrity.
Multiport Plug Valve
Multiport plug valves have more than two ports, making them a cost-effective solution for diverting media in multiple directions. With additional ports, these valves can shut off specific pathways, reducing the need for extra valves in the piping system.
Key Features:
- Multi-Entry Capability: A 4-port valve can handle the tasks of four separate gate valves, offering added flexibility and convenience.
Considerations:
- Leakage Risk: Due to friction, multiport plug valves may not always completely shut off, leading to potential leaks.
- Maintenance Needs: These valves require more frequent maintenance to ensure reliable operation and proper sealing.
Multiport plug valves are a practical choice for simplifying piping systems, but their design necessitates regular upkeep to prevent issues.
Applications for Plug Valves
Plug valves are versatile and widely used across industries, handling gases, liquids, non-abrasive slurries, and more. They are essential for applications such as:
- Fuel Gas Piping Systems
- Chemical Industries
- Fly Ash Applications
- Vacuum to High-Pressure Systems
Key features of plug valves include:
- Quarter-turn manual operation for quick flow control
- On-off, diverting, and moderate throttling services
- Multi-port configurations for flexible flow direction
- Minimal flow resistance for efficient operation
- Reliable performance in hydraulic and gas systems
- Corrosion-resistant options for harsh environments
- Durability and adaptability across various conditions
- Ease of use and maintenance for reduced downtime
Whether in vacuum or high-pressure environments, plug valves offer dependable fluid control, making them indispensable for diverse industrial applications.
Advantages of Using Plug Valves
Versatility
Can be used with large flow rates.
Leak-Tight Capability
The plug valve offers excellent leak-tight performance.
Flow Regulation
Provides tight shut-off, quick opening, and low-pressure drop.
Cost-Effective Operation
The rotational opening and closing mechanism makes plug valves very cost-effective.
Minimal Internal Parts
It has fewer internal parts compared to other valves, enhancing reliability and ease of maintenance.
Low-Pressure Drop
The plug valve features a low-pressure drop because there is no obstruction to the flow of media.
Clog-Resistant Design
One of the advantages of the plug valve is that it does not clog.
Multi-Port Design
A key advantage of the plug valve is its ability to have several ports, reducing the number of valves needed in a piping system.
Fire-Safety and Durability
Reduced likelihood of corrosion or erosion as the actual plug and body seating surface do not get exposed to the line fluid.
Compact Design
Besides being compact and using up less space, gas plug valves offer several advantages.
Versatile Flow Direction
As a multi-port valve, it allows flow media to move in several directions, depending on the pipe system’s requirements.
Suitability for Corrosive Materials
Due to its rotational style, the plug valve is excellent for handling corrosive materials.
Disadvantages of Using Plug Valves
Unsuitability for Throttling Applications
- They are not suitable for throttling applications.
High Actuation Force
- Requires greater force for actuation due to inherently high friction levels.
Risk of Galling
- Presents the possibility of galling under high loads or temperatures.
Reduced Port Design
- The tapered plug design typically leads to a reduced port.
How Does a Plug Valve Work?
A plug valve operates using a plug with a hollow passage inside the valve body. When the valve is in the open position, a quarter-turn motion aligns the passage in the plug with the pipe, allowing fluid to flow through. Turning the valve 90 degrees from the open position moves the plug to block the pipe, putting the valve in the closed state.
Plug valves come in various styles and port configurations:
- Two-Way Plug Valves: These valves have a closure element in the middle, consisting of a plug and a sleeve, and offer a straight-through, two-way service for opening and closing the valve.
- Three-Way Plug Valves: These valves include a third port, usually positioned at a right angle to the inlet. They can be used to divert flow (directing fluid from an inlet to one or both outlets) or combine flow (merging fluid from two inlets into a single outlet).
For a better understanding, you can watch the animated video below, which explains how a plug valve works.
Main Parameter of the Plug Valve
Parameter | Details |
ANSI Plug valve | Class 150LB-2500LB SIZE 1/2″~14″ |
DIN Plug valve | DN50-DN350, PN16~PN40 |
JIS Plug valve | DN50-DN350 10K~63K |
BS Plug valve | DN50 -DN350, PN16~PN40 |
Material | WCB, LCB, WC6, WC9, C12, C5, CF8, CF3, CF3M, CF8M, A105, LF2, F11, F22, F5, F304, F316, F304L, F316L(1/2″-2″), F316L(2″~14″) |
Design & Manufacture Std | API600, API 6D, ASME B16.34, JISB2071, JISB2073, JISB2083, BS 1873, BS1414 |
Face to Face Std | ASME B16.10, DIN 3202, BS2080, API 6D, JISB2002 |
End Connection Std | ASME B16.11, ASME B1.20.1, ASME B16.5, DIN2543-2550, JISB2212-JISB2214 |
Test Standard | ISO5208, BS 6755, API598, API 6D, JISB2003, DIN3230 |
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Additional General Insights Here
Specs of Plug Valve
Material
Plug valves are crafted from materials like stainless steel, cast iron, and bronze, selected for strength, durability, and corrosion resistance. The right material choice depends on the fluid, pressure, and operating conditions, helping extend valve life and boost efficiency.
Sizes and Pressure Ratings
Plug Valves come in a range of sizes, typically from 1/2 inch to 36 inches in diameter. They can handle different pressure ratings, often up to 600 PSI or more. This variety allows for flexibility in matching the right valve to specific project needs, making them versatile for many industrial uses.
Connection Types
Plug Valves comes with different connection types, such as flanged, threaded, and welded ends, allowing for easy integration into existing systems. NTVAL offers a comprehensive range of sizes and connections to meet the specific needs of your projects.
Features of Plug Valve
Compact Design
Plug Valves have a compact design, which makes them space-efficient and easy to install in tight spaces. This design feature allows for flexible installation in various industrial settings, making it a practical choice for complex systems.
Tight Sealing
One of the standout features of Plug Valves is their ability to provide a tight seal. This is achieved through precise engineering and quality materials that prevent leaks and maintain system integrity. The tight sealing capability makes them ideal for applications requiring reliable performance.
Easy Operation
Plug Valves are known for their simple and easy operation. They can be quickly opened or closed with minimal effort, which is beneficial for systems that require frequent adjustments. This ease of operation helps in maintaining efficient flow control in industrial processes.
Benefits of Plug Valve
Reliable Performance
Plug valves deliver reliable performance with sturdy construction and tight sealing, minimizing leaks, failures, and maintenance needs. This consistency ensures smooth, efficient operations in demanding industrial environments.
Cost-Effective Maintenance
Plug valves offer low maintenance, saving time and money. Their durable materials and simple design reduce the need for frequent repairs or part replacements, making them ideal for cost-effective operation in large industrial projects.
Versatile Application
The versatility of Plug Valves means they can be used in various industrial settings, providing flexible solutions for different needs. NTVAL's Plug Valves are built to handle diverse applications, making them a valuable asset in any project.
Applications of Plug Valve
Oil and Gas Industry
Plug Valves are widely used in the oil and gas industry for controlling the flow of crude oil, natural gas, and other hydrocarbons. They are suitable for both upstream and downstream applications, providing reliable performance in drilling, refining, and distribution processes. The bottom line is this – their ability to handle high pressure and temperatures makes them an ideal choice for this demanding industry.
Water Treatment
Plug Valves play a crucial role in water treatment plants, where they are used to control the flow of water and other treatment chemicals. They are effective in both clean and dirty water systems, providing dependable service in filtration, purification, and distribution processes. Their durable construction and easy maintenance make them ideal for the rigorous demands of water treatment facilities.
Chemical Processing
In chemical plants, Plug Valves are essential for managing the flow of various chemicals and fluids. They offer excellent resistance to corrosion and can handle aggressive substances, supporting safe and efficient operations. NTVAL Plug Valves are designed to meet the stringent requirements of chemical processing, making them a trusted choice for these applications.
Mining Operations
In mining operations, Plug Valves are essential for managing the flow of slurries, abrasive fluids, and other mining-related substances. Their sturdy design withstands harsh conditions, including high-pressure environments and the presence of solid particles. These valves help maintain steady operation by preventing blockages and reducing wear in pipelines.
3 Considerations When Buying Plug Valve
01
Environmental Factors
The environment in which the valve will be used can impact its performance. Factors such as exposure to chemicals, humidity, pressure, and temperature variations should be considered. For instance, if the valve is to be used in a corrosive environment, a stainless steel valve might be the best choice. Proper material selection ensures long-term reliability, safety, and optimal functionality.
02
ANSI or API Standards
Make sure the Plug Valve meets relevant industry standards and certifications. Compliance with these standards indicates the valve’s quality and performance. This helps in assuring that the valve will perform reliably under specified conditions. NTVAL’s Plug Valves adhere to these stringent standards, offering reliability and peace of mind. Amazing right?
03
Application Requirements
Finally, consider the specific requirements of your application, such as the type of fluid, flow direction, and control needs. Understanding the demands of your project helps in selecting a Plug Valve that will perform effectively and reliably. For instance, 3-way Plug Valves are useful for applications needing multiple flow paths, while eccentric Plug Valves are better for handling slurries.
Types of Plug Valve
Lubricated Plug Valve
Lubricated Plug Valves use a special lubricant to reduce friction between the plug and the body. This makes them easier to operate and helps them last longer, even in tough conditions. They are ideal for applications that involve high-pressure systems and require a strong seal to prevent leaks.
Sleeve Plug Valve
Sleeve Plug Valves have a non-metallic sleeve that surrounds the plug. This design helps to provide a tight seal and reduces wear on the valve. These valves are suitable for various fluids and gases, offering reliable performance in a range of industrial settings. No doubt about it, these valves are versatile and efficient.
3-Way Plug Valve
3-Way Plug Valves are designed to connect 3 different ports, allowing for multiple flow paths. They are commonly used to switch the flow direction or mix different fluids. NTVAL offers high-quality 3-way Plug Valves that are built to handle complex flow requirements with ease.
Eccentric Plug Valve
Eccentric Plug Valves feature an offset plug, which helps to reduce wear and provide a tight shut-off. This design is particularly useful for handling slurries and fluids with solid particles. They offer durability and reliability, making them a valuable addition to any industrial project.
Dive Deeper Into Our Resources
Looking for more diverse product options? Browse through our handpicked selections:
For some insightful reads, we’ve curated a list of recommended articles just for you:
- 4 Different Types of Plug Valves
- The Essential Guide to Gas Plug Valves
- Top 9 Plug Valve Manufacturers
- 8 Maintenance Tips for Plug Valves
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