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Bronze Disc for Butterfly Valve

Product Description

The bronze disc is one of the key components of a butterfly valve, mounted inside the valve body and connected with the stem and seat to control on-off and flow regulation. Manufactured from high-quality bronze alloys, the disc provides excellent corrosion resistance and mechanical strength, making it especially suitable for seawater, brine, and mildly corrosive environments.

1，Materials

C95400，C95500，C95800，C83600，RG102，Typical materials include:

C95400 Aluminum Bronze，C95500/C95800 Nickel Aluminum Bronze

C83600 Cast Bronze，RG10 Naval Bronze

3，Features & Advantages

Excellent corrosion resistance for seawater and saline environments

High strength and toughness for reliable long-term operation

Wear resistance for extended valve service life

Precision casting ensures perfect sealing with the valve seat

4，Applications

Marine piping systems (ballast water, cooling water, fire-fighting lines)

Desalination plants

Offshore engineering platforms

Brine and chemical pipelines

Concentric Type Butterfly Valve with Pin and Pinless

Concentric Butterfly Valve with Pin

Structure: The disc is fixed to the stem by pins, ensuring direct and reliable connection.

Advantages:

Simple manufacturing process and easy assembly.

Reliable torque transmission between the disc and the stem, not easy to slip.

Suitable for larger torque and frequent open/close operations.

Disadvantages:

Pin holes may become corrosion points, especially in seawater or corrosive media.

Possible leakage through pin holes.

Not as precise or tight as pinless design in high sealing requirements.

Concentric Butterfly Valve without Pin (Pinless)

Structure: The disc is fixed to the stem by interference fit, keyway, or integral casting, without using pins.

Advantages:

Eliminates pin holes, reducing leakage risk.

Better corrosion resistance, especially suitable for marine, seawater desalination, and offshore applications.

Stronger integrity between disc and stem, cleaner appearance.

Disadvantages:

Higher manufacturing and assembly precision required.

Maintenance is more complex if the connection loosens.

Generally higher cost than pinned design.

 

With Pin → Traditional design, lower cost, suitable for general conditions.

Pinless → Better corrosion resistance and sealing performance, more suitable for marine use and high-end markets.

Installation Locations of Dual-Plate Check Valves on Ships

Dual-plate check valves are mainly installed in pipelines where the medium flows in one direction, preventing backflow and reducing water hammer impact. On ships, typical installation locations include:

1. Engine Room Systems

Main Seawater Cooling System
Installed between the sea chest valve and the seawater pump, or between the pump outlet and the cooler, to prevent seawater from flowing back when the pump stops.

Freshwater Cooling System
Located at the outlet of the cooler to prevent backflow of cooling water to the equipment.

Fuel and Lube Oil Cooling Systems
Installed at the cooler or pump outlet to prevent oil from flowing back after the pump stops.

2. Ballast and Tank Systems

Ballast Water System
Between the ballast pump outlet and the ballast tanks to prevent water from flowing back, especially in systems with multiple pumps or tanks where each branch line needs a check valve.

Tank Drain Systems
To prevent liquid from one tank from flowing into another.

3. Firefighting and Emergency Systems

Firefighting System
At the outlet of the fire pump or branch lines to prevent backflow to the pump or other systems.

Emergency Pump Systems
To prevent cross-flow between the emergency pump and the main pump.

Installation Notes:

Can be installed horizontally (shaft vertical) or vertically (flow upward).

Should be located close to the pump outlet to minimize backflow and water hammer.

The arrow on the valve body must align with the flow direction of the pipeline.

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!

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