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SS316 Wafer Type Single Disc Check Valve

Reliable Backflow Protection – Built for Harsh Marine and Industrial Environments

Product Overview

Our SS316 Single Disc Check Valve is designed for high-performance backflow prevention in demanding environments such as marine systems, chemical plants, and water treatment facilities. Made from 316 stainless steel, it offers exceptional resistance to corrosion, even in seawater and aggressive media.

With its compact wafer-type body and single disc design, it ensures fast response, minimal pressure drop, and easy installation between flanges.

Key Features

Material: SS316 Body & Disc – excellent corrosion resistance

Design: Compact wafer type, single disc for fast shut-off

Seal Options: EPDM / NBR / PTFE – compatible with various media

Installation: Horizontal or vertical (upward flow)

Pressure Rating: PN10 / PN16 / ANSI150 available

Sizes: DN40 to DN600 (larger sizes customizable)

Applications

Marine pipelines (ballast systems, cooling water, bilge lines)

Offshore platforms

Chemical and pharmaceutical industries

Water treatment & desalination systems

Pump discharge lines

Why Choose Us

Over 15 years in precision casting and valve component manufacturing

OEM/ODM services available

Fast lead times, reliable quality

Export-ready with international shipping & documentation support

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here:https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/.

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.

We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Connection Standard of Dual Plate Check Valve

The connection standard of a Dual Plate Check Valve primarily refers to the standards governing the face-to-face dimensions, flange compatibility, and pressure ratings. These standards ensure that the valve can be installed easily in various pipeline systems with flanged connections.

Key Connection Standards for Dual Plate Check Valves:

1. API 594 – Check Valve Face-to-Face and End Connection Dimensions

  • Specifies the face-to-face dimensions of wafer, lug, and double-flanged check valves.
  • Ensures interchangeability between different manufacturers’ valves.
  • Widely used in industries such as oil & gas, petrochemical, and water treatment.
  • Applicable pressure classes:
    • Class 150, 300, 600, 900, 1500, 2500

2. ASME B16.5 – Pipe Flanges and Flanged Fittings

  • Defines the dimensions, materials, and pressure ratings for flanges up to 24 inches.
  • Used to ensure flange compatibility when installing the valve.
  • Flange pressure classes:
    • Class 150, 300, 600, 900, 1500, 2500

3. ASME B16.47 – Large Diameter Steel Flanges

  • Covers flange sizes from 26 inches to 60 inches.
  • Used in large-diameter piping systems.

4. EN 558 / ISO 5752 / DIN 3202 – Face-to-Face Dimensions of Valves

  • European and international standards defining face-to-face dimensions for valves.
  • These standards ensure compatibility with flanged connections under PN-rated systems.
  • Pressure ratings: PN 10, 16, 25, 40.

5. EN 1092-1 – Steel Flanges

  • European standard for flange dimensions, materials, and pressure ratings.
  • Common pressure ratings: PN 10, 16, 25, 40, 63, 100.

End Connection Types:

Wafer Type:

  • Designed to fit between two flanges with bolts passing through.
  • Compatible with multiple flange standards (ASME, EN, JIS, etc.).
  • Most compact and lightweight connection type.

Lug Type:

  • Equipped with threaded lugs around the circumference.
  • Allows the valve to be bolted directly to the flanges, enabling installation at the end of a pipeline.

Double Flanged Type:

  • Designed with integral flanges for bolted connections on both sides.
  • Provides more rigid support compared to wafer and lug types.

Summary of Pressure Ratings:

Standard Pressure Class Typical Notation
ASME B16.5 150 – 2500 Class 150, 300, etc.
EN 1092-1 PN 10 – PN 100 PN 10, PN 16, etc.
API 594 150 – 2500 Class 150, 300, etc.
JIS B2220 5K – 63K JIS 10K, 16K, etc.

 

 

Electroplating of Single Plate Check Valves

Electroplating is a surface treatment process for single-plate check valves that aims to enhance their corrosion resistance, wear resistance, and aesthetic appeal. This process is particularly suited for valves operating in corrosive environments for extended periods. Below is an overview of the electroplating process and key considerations for single-plate check valves:

Common Electroplating Types

Zinc Plating

  1. Features: Economical and practical; suitable for low-corrosion environments.
  2. Applications: Commonly used in indoor or mildly corrosive conditions.

Nickel Plating

  1. Features: Excellent corrosion resistance and decorative finish with a smooth surface.
  2. Applications: Ideal for medium-corrosion environments with higher demands.

Chrome Plating

  • Features: High wear resistance, hardness, and surface gloss.
  • Applications: Used in industrial environments with high wear and corrosion.

Zinc-Aluminum Alloy Plating

  • Features: Combines the advantages of zinc and aluminum for superior corrosion resistance.
  • Applications: Suitable for harsh environments, such as marine climates or chemical plants.

Multilayer Composite Plating

  • Features: Combines multiple metal layers to enhance overall performance.
  • Applications: High-demand scenarios, such as aerospace and marine industries.

Electroplating Process

Pre-treatment

  1. Degreasing: Cleans oil and grease from the surface using an alkaline solution.
  2. Rust Removal: Removes surface rust via acid pickling or mechanical methods.
  3. Surface Activation: Improves plating adhesion.

Electroplating Stage

  1. Primary Electroplating: The valve is placed in an electrolyte solution, where a chemical reaction deposits the metal layer.
  2. Post-Plating Treatment: Includes passivation to enhance corrosion resistance.

Inspection and Post-Treatment

  1. Plating Thickness Check: Ensures the layer meets design specifications.
  2. Appearance Check: Inspects for defects such as bubbles or cracks.
  3. Sealing Treatment: Seals the plating layer to improve corrosion resistance.

Key Considerations

Material Selection
The substrate material of the single-plate check valve must be identified before electroplating. Common materials include cast iron, stainless steel, and carbon steel, which may require different plating processes.

Plating Thickness
Determine the plating thickness based on the operating environment, typically ranging from 5 to 25 microns.

Environmental Compliance
Some electroplating processes involve hazardous substances (e.g., hexavalent chromium). Compliance with environmental regulations is essential, and eco-friendly plating options should be prioritized.

Adhesion Testing
Ensure strong adhesion between the plating and substrate to prevent peeling or flaking.

Corrosion Resistance Testing
Validate the plating’s corrosion resistance through salt spray tests and other methods.

Conclusion

Electroplating significantly improves the service life and performance of single-plate check valves. Selecting the appropriate plating process and ensuring stringent quality control are critical. For customized electroplating solutions, consult a professional surface treatment provider or manufacturer.

Corrosion Prevention Methods for WCB Material Valve Bodies in Marine Valves

WCB material (carbon steel castings) is prone to corrosion in certain environments, especially in marine applications. To enhance the service life of WCB valves, effective corrosion prevention methods are necessary. Here are some common approaches:

1. Cathodic Protection

  • Principle:Install sacrificial anodes (e.g., zinc or magnesium blocks) on the valve body to protect it from corrosion through electrochemical reactions.
  • Application:Commonly used in seawater pipelines on ships to prevent salt-induced corrosion.

2. Surface Coating Protection

  • Anti-corrosion Coatings:Apply protective coatings, such as epoxy resin or polyurethane, to the valve surface to create a barrier against corrosive media.
  • Metallic Coatings:Use thermal spraying to apply a corrosion-resistant metal layer (e.g., aluminum or zinc alloys) on the surface.
  • Key Requirement:The coating should be uniform, durable, and provide strong adhesion, especially in areas like threads and internal surfaces.

3. Internal Lining with Corrosion-resistant Materials

  • Method:Line the internal surfaces of the valve with corrosion-resistant materials, such as rubber, fluoroplastics (PTFE), or lead.
  • Advantages:Directly protects the valve from contact with corrosive media, significantly extending its service life.
  • Application:Ideal for systems handling highly acidic or alkaline fluids.

4. Application of Anti-rust Oil or Lubricants

  • Regular Maintenance:Apply anti-rust oil or lubricants to the valve surface, especially for valves that are not in regular use.
  • Application:Effective in humid or salt-laden environments typical in marine settings.

5. Material Modification or Upgrades

If the environment involves severe corrosion (e.g., sulfur gases, acidic water), WCB material can be treated or upgraded:

  • Chromium or Nickel Surface Treatment:Enhances oxidation and corrosion resistance.
  • Use of Alloy Materials:Opt for higher-grade materials like CF8 or CF8M (stainless steel valve bodies) for better performance.

6. Electroplating

  • Methods:Apply zinc, nickel, or chromium plating to the WCB valve body using electroplating techniques.
  • Advantages:Provides a dense, wear-resistant, and corrosion-resistant surface with a polished appearance.

7. Environmental Control

  • Reduce Exposure:Minimize direct contact with high-salinity air or water.
  • Cleaning and Maintenance:Regularly clean salt, dirt, or corrosive deposits from the valve surface to keep it in optimal condition.

8. Combination of Methods

  • Coating + Cathodic Protection:Combining surface coatings with cathodic protection can effectively address different types of corrosion and provide comprehensive protection.

Selection Criteria for Corrosion Prevention

  • Environmental Conditions:Whether the valve is exposed to seawater or acidic/alkaline environments.
  • Media Type:The corrosiveness of the fluids being handled.
  • Valve Type and Parts:Different requirements for internal passages and external valve body protection.
  • Cost-effectiveness:Balancing the cost of corrosion prevention with the expected service life.

In the marine industry, a combination of coatings and cathodic protection is widely used to ensure the durability of WCB material valves. If you have specific application scenarios, the prevention strategy can be further optimized.

Rubber Seats in Marine Butterfly Valves

Rubber seats are widely used in marine butterfly valves, particularly in the design of centerline butterfly valves. These rubber seats offer excellent sealing performance, prevent medium leakage, and resist corrosion and wear in the marine environment. Below are some key characteristics and applications of rubber seats in marine butterfly valves:

marine valve seat

marine valve seat

1. Excellent Sealing Performance

Due to their flexible material, rubber seats can tightly fit the valve disc, ensuring good sealing. Even under low-pressure conditions, they effectively prevent leakage, which is crucial for the safety of ship systems.

2. Corrosion Resistance

As ships operate in marine environments, their piping systems are often exposed to seawater. Rubber seats, typically made from materials such as neoprene (CR), EPDM, and nitrile rubber (NBR), offer excellent corrosion resistance and can withstand exposure to seawater, oils, and other mediums, thereby extending the valve’s service life.

3. Wear Resistance and Aging Resistance

Rubber seats in marine butterfly valves are typically resistant to wear and aging. This allows the valve to maintain good sealing performance over long periods without aging or failure, making them especially suitable for systems with frequent opening and closing operations.

4. Easy Replacement and Maintenance

The design of rubber seats makes them easy to replace, particularly in the maintenance of marine piping systems. Due to the elasticity of the rubber material, installation and removal are relatively simple, reducing maintenance time and cost.

5. Adaptability to Different Temperatures and Pressures

Rubber seats used in marine systems are typically capable of handling a wide range of temperatures and pressures, making them suitable for various ship applications, including cooling water systems, ballast water systems, and firefighting systems.

Common Materials and Applications

  • Neoprene (CR): Suitable for seawater, oils, and other mediums, widely used in seawater cooling and ballast water systems.
  • EPDM: Offers excellent acid, alkali, and heat resistance, making it ideal for freshwater and air systems.
  • Nitrile Rubber (NBR): Has strong oil resistance, suitable for fuel systems.
  • fluororubber (Viton or FKM):typically withstanding temperatures above 200°C, making it suitable for high-temperature piping systems.

Rubber seats are an essential component in marine butterfly valves. Their sealing performance, corrosion resistance, wear resistance, and ease of maintenance make them indispensable in the marine industry.

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here:   https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Disc Materials of Butterfly Check Valve（dual plate check valve)

The disc of a butterfly check valve plays a crucial role in controlling the flow of fluids by pivoting on a central axis to either open or close the valve. Depending on the application, pressure, and the fluid being handled, different materials are used for manufacturing the disc. Below are common materials used for butterfly check valve discs:

1. Stainless Steel

  • Grades: 304, 316, 316L
  • Characteristics: High resistance to corrosion, good mechanical properties, and durability. Suitable for water, steam, chemical, and food-grade applications.
  • Common Uses: Petrochemical, food and beverage, and water treatment industries.

2. Carbon Steel

  • Characteristics: Strong and cost-effective, but less corrosion-resistant than stainless steel. Usually requires coatings for corrosion protection.
  • Common Uses: General-purpose industrial applications where corrosion resistance is not a primary concern.

3. Ductile Iron

  • Characteristics: Combines strength and flexibility, offering good toughness and ductility. Requires coating (e.g., epoxy) for corrosion resistance.
  • Common Uses: Water distribution, wastewater, and low-pressure applications.

4. Aluminum Bronze

  • Characteristics: High corrosion resistance, particularly in seawater and marine environments. Good strength and wear resistance.
  • Common Uses: Marine, seawater handling, and desalination plants.

5. Nylon-Coated Disc

  • Characteristics: Nylon coating provides enhanced wear resistance and some degree of corrosion protection. Suitable for mildly corrosive environments.
  • Common Uses: Low-pressure industrial applications.

6. Elastomer-Lined Disc (Rubber)

  • Materials: EPDM, NBR (Nitrile), FKM (Viton)
  • Characteristics: The disc is typically coated with elastomeric materials to provide a bubble-tight seal and resist specific chemicals. Different elastomers offer various resistances to temperature, chemicals, and abrasives.
  • Common Uses: Applications requiring chemical resistance or sanitary conditions, like food processing and chemical plants.

7. Hastelloy

  • Characteristics: Highly resistant to corrosive and harsh chemical environments, particularly acids and oxidizing agents.
  • Common Uses: Chemical processing, pharmaceuticals, and industries dealing with corrosive fluids.

8. Monel

  • Characteristics: Extremely resistant to corrosion, particularly from acids, alkalis, and seawater. Excellent mechanical strength.
  • Common Uses: Marine, oil & gas, chemical, and heat exchanger applications.

9. Titanium

  • Characteristics: Exceptional resistance to corrosion in seawater, chlorides, and acidic environments. Lightweight and highly durable.
  • Common Uses: Aerospace, marine, chemical, and desalination applications.

The selection of disc material in a butterfly check valve is based on factors like the type of fluid being handled, the operating temperature and pressure, and the desired longevity of the valve.

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here:   https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Body Materials of Butterfly Check Valve

Butterfly check valves, used to prevent backflow in piping systems, are made from various materials depending on the application, fluid type, and operating conditions. The most common body materials for butterfly check valves include:

  1. Cast Iron:

Usage: Often used in general water applications, HVAC, and non-corrosive fluid systems.

Properties: Economical, good strength, and durability, but prone to corrosion if not coated.

2. Ductile Iron:

  • Usage:Preferred in water and sewage systems, oil and gas applications.
  • Properties:Stronger and more flexible than cast iron, offers better corrosion resistance and can handle higher pressures.

3. Carbon Steel:

  • Usage:Suitable for high-pressure and high-temperature applications such as oil, gas, and steam systems.
  • Properties:Strong and durable, but requires corrosion protection (e.g., coatings or linings) when used with corrosive media.

4. Stainless Steel (304, 316):

  • Usage:Common in corrosive environments, such as chemical processing, food, and pharmaceutical industries.
  • Properties:Excellent corrosion resistance, especially in environments involving chemicals or saltwater. More expensive but ideal for long-term durability in harsh conditions.

5. Aluminum Bronze:

  • Usage:Often used in marine applications or systems involving seawater.
  • Properties:High corrosion resistance, particularly in seawater and other saline environments.

6. PVC (Polyvinyl Chloride) / Plastic:

  • Usage:Frequently used in low-pressure systems, particularly in chemical or water treatment applications.
  • Properties:Lightweight, corrosion-resistant, and economical, but limited by temperature and pressure constraints.

7. Titanium:

  • Usage:Used in highly corrosive environments, such as in the chemical industry.
  • Properties:Excellent corrosion resistance and high strength-to-weight ratio, but expensive.

Each material is selected based on the specific application requirements, such as pressure, temperature, fluid type, and environmental conditions.

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here:   https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Feature of Concentric Type Butterfly Valve with Carbon Steel Body

A concentric butterfly valve with a carbon steel body is a common type of valve used in industrial applications for regulating or isolating the flow of fluids. The concentric design means that the valve disc and stem are aligned on the same axis, making it suitable for low-to-moderate pressure applications. Below are the key features of this type of valve:

  1. Concentric Design (Centerlined)

Shaft and Disc Alignment: The shaft (or stem) is centrally located in the valve body, and the disc rotates on the same axis as the shaft. This allows for even pressure distribution on the valve seat.

No Offsets: Unlike offset butterfly valves, concentric valves have no displacement of the shaft relative to the seat and disc, making them simpler and easier to maintain.

  1. Carbon Steel Body

Material Strength: Carbon steel is strong and durable, suitable for applications that involve moderate pressure and temperature.

Corrosion Resistance: Carbon steel provides moderate corrosion resistance but may require external coatings (such as epoxy) or internal linings to protect against aggressive chemicals or moisture.

Temperature Tolerance: Carbon steel can withstand relatively high temperatures (up to approximately 425°C or 800°F), making it appropriate for steam, oil, or gas applications.

Cost-Effective: Carbon steel is less expensive compared to stainless steel, making it a cost-effective solution for many industrial applications.

  1. Soft Seat

Elastomeric Seat: Concentric butterfly valves typically use soft seats made from elastomeric materials like EPDM, Nitrile (Buna-N), or PTFE. These materials provide a bubble-tight seal, especially in low-pressure applications.

Replaceable Seat: The seat is often replaceable, which allows for easy maintenance and longer valve life.

Leakage Protection: Soft seats offer good sealing performance and can achieve zero leakage (Class VI shutoff).

  1. Disc Design

Material: The disc is typically made of stainless steel, ductile iron, or other alloys to provide enhanced corrosion resistance in different environments.

Low Flow Resistance: When the valve is fully open, the disc is parallel to the flow of the fluid, resulting in minimal flow resistance and a low-pressure drop.

Tight Shutoff: The disc is designed to provide tight shutoff, making the valve ideal for applications where leakage prevention is critical.

  1. Bi-Directional Flow

The concentric butterfly valve is capable of controlling the flow of fluids in both directions, enhancing its versatility in piping systems.

  1. Low Torque Requirement

The concentric design requires low torque for operation. This makes the valve easier to operate manually and reduces the power needed for actuation when automated.

  1. Compact and Lightweight

Space-Saving: Butterfly valves are compact and lightweight compared to other valve types like gate or globe valves. This makes installation easier and reduces the weight on piping systems, especially in larger diameter applications.

  1. Wafer or Lug Type Connection

Wafer Type: Designed to fit between two flanges using long bolts that pass through both flanges and the valve body.

Lug Type: Features threaded inserts, allowing the valve to be installed between flanges and secured with bolts on each side. This enables removal of downstream piping without disturbing the upstream piping.

  1. Operation Options

Manual Operation: Operated using a handwheel or lever for simple, on/off control.

Automated Operation: The valve can be equipped with pneumatic, electric, or hydraulic actuators for remote or automated control.

  1. Applications

Suitable for low-to-moderate pressure and temperature applications in industries like:Water Treatment: Used in pipelines for water distribution and wastewater treatment.

HVAC Systems: Applied in heating, ventilation, and air conditioning systems for flow regulation.

Oil & Gas: Used in gas transmission pipelines, oil refineries, and other industrial applications involving non-corrosive fluids.

Chemical Processing: Ideal for handling non-corrosive chemicals, light acids, and alkaline solutions.

Power Generation: Common in cooling water and steam lines.

  1. Easy Maintenance

The simple design of the concentric butterfly valve with fewer moving parts allows for easy maintenance. The seat and disc are generally replaceable, reducing downtime and operational costs.

  1. Pressure and Temperature Range

Pressure Rating: Typically suitable for low to medium pressure applications (up to 300 PSI or higher depending on the design).

Temperature Range: Can handle a wide range of temperatures, especially when paired with appropriate seat materials. However, soft-seated valves are more suitable for moderate temperature ranges.

  1. Cost-Effective Solution

Concentric butterfly valves with carbon steel bodies offer an economical solution for applications where high durability, moderate pressure handling, and cost-efficiency are required, making them popular for general-purpose use in industries like water treatment, HVAC, and oil and gas.

Summary of Key Benefits:

Cost-Effective: Carbon steel is affordable, and concentric valves are simpler in design.

Durable: Withstands moderate temperature and pressure applications.

Compact: Saves space and reduces the overall weight of the piping system.

Easy to Maintain: Simple design with replaceable parts.

Versatile: Suitable for water, gas, steam, and light chemical handling.

 

These features make concentric butterfly valves with carbon steel bodies ideal for a variety of applications that require reliability, cost-efficiency, and easy maintenance.

 

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here:   https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Concentric type Butterfly Valve with Ductile Iron Body and Bronze Disc

A Concentric Type Butterfly Valve with a Ductile Iron Body and Bronze Disc is a reliable and versatile valve used for controlling fluid flow in various applications. Here’s a breakdown of its features:

Key Features:

Body Material: Ductile Iron

Ductile iron is a strong and durable material with excellent mechanical properties, including good tensile strength, flexibility, and resistance to cracking. It is preferred over cast iron due to its enhanced toughness.

Ideal for medium-pressure applications, ductile iron can withstand significant stress and offers long-term durability in harsh environments.

 

Disc Material: Bronze

Bronze is known for its superior corrosion resistance, particularly in water-based systems, and is often chosen for its ability to handle a wide range of fluids, including water, oil, and steam.

A bronze disc ensures smooth operation and longer service life in environments where metal-to-metal wear or corrosion could be a concern.

 

Concentric Design

In a concentric butterfly valve, the disc and the stem are centrally aligned. This provides a uniform sealing surface and is typically used in low- to medium-pressure systems.

The disc is centered within the valve body, and the valve opens and closes by rotating the disc 90 degrees on a shaft.Sealing Mechanism

Concentric butterfly valves typically use a resilient seat (like EPDM or NBR) that presses against the bronze disc to create a tight seal, preventing leaks.

Operation

This valve can be manually operated with a lever or gear mechanism or automated using pneumatic or electric actuators.

Common Applications:

Water Treatment and Distribution: Suitable for potable water, sewage, and wastewater systems.

HVAC Systems: Used for regulating flow in heating and cooling systems.

Irrigation Systems: Controls water flow in agricultural irrigation.

General Industrial Processes: Can be used in chemical, petrochemical, and other industrial applications where corrosion resistance is essential.

Advantages:

Cost-effective: The combination of ductile iron and bronze makes this type of valve both affordable and reliable.

Corrosion Resistance: The bronze disc ensures superior resistance to corrosion, particularly in water and steam applications.

Ease of Maintenance: Simple design allows for easy maintenance and repair.

This valve is a practical choice for a variety of fluid control systems due to its durability, ease of operation, and resistance to harsh environments.

 

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here:   https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

 

Maintenance of the Concentric type Butterfly Valve in Ships

The maintenance of a concentric (centered) butterfly valve in ships is essential to ensure the valve’s optimal performance and longevity, especially in harsh marine environments. Concentric butterfly valves have the disc located in the center of the valve body, with a resilient seat that helps to seal the valve when closed. These valves are commonly used for fluid control in various ship systems, including seawater cooling, ballast systems, and bilge systems. Here’s a guide to maintaining a concentric butterfly valve on ships:

  1. Visual Inspection

External Inspection:Regularly check the valve for any visible signs of corrosion, wear, or damage, especially around the body, stem, and handle or actuator.

Marine environments are prone to corrosion due to saltwater, so special attention should be given to areas exposed to seawater.

Inspect for any salt deposits, marine growth, or other debris that may accumulate around the valve body and flanges.

Seal Inspection:Inspect the valve’s seat (usually made of rubber or elastomer) for wear or damage. The seal is crucial for the valve’s tight closure.

Check for cracks, deformities, or wear in the seal that could lead to leakage. The seal is one of the most critical parts, and its condition directly affects valve performance.

  1. Regular Cleaning

Valve Cleaning:Clean the exterior and interior of the valve regularly to remove any buildup of marine organisms, rust, silt, or debris that may impair its function.

Use approved marine cleaning agents that do not damage the valve’s materials. After cleaning, thoroughly rinse the valve with freshwater to remove any residual chemicals.

Seal and Disc Cleaning:Gently clean the valve’s disc and seat to remove any deposits. Marine organisms, like barnacles or algae, can settle on the disc, potentially impacting valve closure.

  1. Lubrication

Stem and Moving Parts:

Lubricate the stem and other moving parts of the valve as per the manufacturer’s recommendations. Marine-grade lubricants should be used to prevent corrosion and ensure smooth operation.

Avoid over-lubricating, as excess lubricant can attract dirt or debris.

Actuator Lubrication (for automated valves):

If the valve is equipped with an actuator (pneumatic, hydraulic, or electric), ensure that the actuator’s moving parts are adequately lubricated. Regularly check actuator connections to ensure they are secure and functioning smoothly.

  1. Operational Testing

Open and Close Testing:Periodically operate the valve by fully opening and closing it to ensure the disc moves freely. A valve that isn’t operated regularly may become stiff or difficult to operate due to corrosion, buildup, or seal hardening.

Ensure that there are no sticking points, and check the valve handle or actuator for any issues.

Leakage Testing:Perform a hydrostatic or pneumatic test at operating pressure to detect any leaks. If leakage is found, inspect the seat, seal, and disc for damage.

For valves under critical operation (e.g., seawater intake or discharge), this test should be part of routine inspections.

  1. Seal Replacement

Seal and Seat Maintenance:

The resilient seat is a key component that provides a bubble-tight seal in a concentric butterfly valve. Over time, the seat can wear out or become damaged due to constant use or exposure to chemicals, requiring replacement.

Replace the valve seat if you notice signs of cracking, deformation, or excessive wear that could compromise its sealing ability.

Stem Seals:

Inspect the stem seals (o-rings or gaskets) for wear. If these seals fail, it could lead to leakage around the stem area.

  1. Corrosion Protection

Protective Coating:

Apply protective coatings, like marine-grade anti-corrosive paints, to the external parts of the valve that are exposed to saltwater or humid environments.

If the valve is made from a material prone to rust (such as certain grades of cast iron), extra attention should be given to keeping the body protected from corrosion.

Material Compatibility:

Ensure that the valve material (body and disc) is suitable for the specific fluid or gas being handled. Corrosion-resistant materials like stainless steel or bronze should be used for seawater applications.

  1. Actuator and Control System Maintenance

Actuator Inspection:

For automatic valves, inspect the actuator system regularly. Check for signs of wear, corrosion, or malfunction in the actuator.

Ensure the actuator’s control signals are accurate, and the valve opens and closes fully when triggered.

Control System Calibration:

If the valve is part of an automated control system, periodically calibrate the system to ensure it operates at the correct parameters (e.g., pressure or flow settings).

  1. Bolts and Flange Check

Tightness of Flange Bolts:Periodically check the tightness of the bolts securing the valve to the pipe flanges. Marine vibrations can loosen these bolts over time.

Use the manufacturer-recommended torque settings when tightening bolts to avoid over-tightening or damaging the valve body.

  1. Gasket Inspection

Flange Gasket:Check the condition of flange gaskets between the valve and pipe flanges. If leaks are detected, the gasket may need to be replaced.

Gaskets exposed to high pressure, temperature, or aggressive fluids might degrade faster and require more frequent replacement.

Summary of Key Maintenance Practices:

Regular inspection: Visual and operational checks for corrosion, leaks, and damage.

Cleaning: Routine cleaning of valve components to remove marine growth and deposits.

Lubrication: Ensure moving parts are lubricated using marine-grade products.

Seal and gasket maintenance: Inspect and replace the valve seat, stem seals, and flange gaskets as needed.

Operational tests: Open and close the valve to ensure smooth operation.

Corrosion protection: Apply anti-corrosion coatings and ensure material compatibility with seawater.

Maintenance Schedule:

Weekly: Visual inspections, operational testing, and cleaning of external surfaces.

Monthly: Internal cleaning, actuator system checks, and lubrication.

Annually: Comprehensive inspections, including seal, gasket, and bolt checks; perform leakage tests and replace worn-out components.

Maintaining concentric butterfly valves on ships is crucial for ensuring the reliability of fluid systems, preventing leaks, and extending the valve’s service life.

 

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here:   https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

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