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Marine Butterfly Valve Certifications Explained: ABS, DNV, CCS, and LR

Marine butterfly valves used in shipbuilding and offshore applications must comply with the rules and requirements of recognized marine classification societies. Certifications issued by these organizations ensure safety, reliability, and regulatory acceptance throughout a vessel’s service life.

What Are Marine Classification Societies?

Marine classification societies are independent organizations that establish technical standards for the design, manufacture, and inspection of marine equipment. Valves installed on board ships must meet these standards to be accepted by shipowners, shipyards, and marine authorities.

Among the most widely recognized classification societies are:

ABS – American Bureau of Shipping/DNV – Det Norske Veritas

CCS – China Classification Society/LR – Lloyd’s Register

Why Certifications Are Important for Marine Butterfly Valves

Marine butterfly valves are critical components in seawater, ballast, fire-fighting, and general service systems. Certification ensures that valves:

Meet approved design and material requirements

Are manufactured under controlled quality systems

Have been inspected and tested according to marine standards

For shipowners, certified valves reduce operational risk and simplify approval during vessel construction or maintenance.

Scope of Certification for Butterfly Valves

Marine butterfly valve certification may cover:

Valve design and pressure rating/Body, disc, and shaft materials

Manufacturing process and quality control/Pressure and functional testing

Traceability and inspection records

Certification can be applied on a project basis or through type approval, depending on the classification society and application.

Project Certification vs Type Approval

Project Certification:
Valves are inspected and certified for a specific vessel or project. This approach is commonly used for customized or special marine applications.

Type Approval:
A valve design is tested and approved for repeated use across multiple projects, reducing approval time and simplifying procurement.

Both approaches are accepted by classification societies such as ABS, DNV, CCS, and LR.

Conclusion

Marine butterfly valve certifications play a vital role in ensuring safety, performance, and regulatory compliance in shipbuilding projects. Selecting a manufacturer capable of supplying valves in accordance with ABS, DNV, CCS, and LR requirements is essential for shipowners and shipyards.

Tianjin Tanghai Dongyang Valve Co., Ltd. supplies marine butterfly valves that can be manufactured and inspected in accordance with the requirements of ABS, DNV, CCS, and LR for global shipbuilding and marine applications.

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/u-type-flange-butterfly-valve-th-btv-utf/

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!

Soft Seated vs Metal Seated Butterfly Valves for Marine Use

Choosing the right butterfly valve type is critical for reliable operation in marine systems. Among the most common options, soft seated and metal seated butterfly valves each offer distinct advantages depending on the application and operating conditions.

What Is a Soft Seated Butterfly Valve?

A soft seated butterfly valve uses an elastomer or polymer seat, such as EPDM, NBR, or PTFE, to achieve tight shut-off performance.

Key advantages of soft seated butterfly valves:

Excellent sealing performance/Bubble-tight shut-off/Lower operating torque

Suitable for low to medium temperature and pressure

In marine applications, soft seated butterfly valves are commonly used in:

Seawater cooling systems/Ballast water systems/General service piping

They are preferred where reliable sealing and ease of operation are priorities.

high performance-double eccentric-butterlfy valve-wafer-lug-flanged (5)

What Is a Metal Seated Butterfly Valve?

A metal seated butterfly valve uses metal-to-metal contact between the disc and seat. This design is intended for harsher operating conditions.

Key advantages of metal seated butterfly valves:

Higher temperature resistance/Better performance under abrasive conditions

Longer service life in demanding environments

Metal seated butterfly valves are typically applied in:

High-temperature marine systems/Systems with suspended particles

Special-duty marine applications

Key Differences for Marine Applications

When selecting between soft seated and metal seated butterfly valves for marine use, the following factors should be considered:

Sealing performance:
Soft seated valves provide superior tight shut-off, while metal seated valves allow minimal leakage depending on design.

Operating conditions:
Soft seated valves are suitable for normal seawater service, whereas metal seated valves are better for higher temperatures and severe conditions.

Maintenance and service life:
Soft seats may require replacement over time, while metal seats offer longer durability under extreme conditions.

Compliance with Marine Standards

Both soft seated and metal seated butterfly valves can be manufactured in accordance with marine classification society requirements, including ABS, DNV, CCS, and LR, ensuring acceptance by shipowners and shipyards.

Conclusion

There is no universal solution for all marine systems. Soft seated butterfly valves are ideal for applications requiring tight sealing and smooth operation, while metal seated butterfly valves are better suited for high-temperature or severe service conditions.

Tianjin Tanghai Dongyang Valve Co., Ltd manufactures both soft seated and metal seated marine butterfly valves, providing solutions compliant with ABS, DNV, CCS, and LR requirements for shipbuilding and marine projects.

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/lug-type-butterfly-valve-th-btv-lt/

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!

What Is C95400 Bronze Butterfly Valve Disc？

C95400 bronze is a commonly used aluminum bronze material for butterfly valve discs in marine and shipbuilding applications. It is well known for its excellent strength, corrosion resistance, and reliability in seawater environments.

Overview of C95400 Aluminum Bronze

C95400 is an aluminum bronze alloy primarily composed of copper, aluminum, and iron. This material offers a unique combination of high mechanical strength and outstanding resistance to corrosion, making it suitable for demanding marine conditions.

Compared with standard bronze materials, C95400 provides:

Higher tensile strength/Better wear resistance/Improved performance in seawater service

Why C95400 Is Used for Butterfly Valve Discs

The valve disc is the most critical component of a butterfly valve, as it is directly exposed to the fluid medium. In marine systems, seawater corrosion is one of the main challenges.

C95400 bronze butterfly valve discs are widely selected because:

They resist seawater corrosion and erosion

They maintain dimensional stability under pressure

They reduce the risk of pitting and surface degradation

These characteristics ensure smooth operation and reliable sealing performance throughout the valve’s service life.

Typical Marine Applications

C95400 bronze butterfly valve discs are commonly used in:

Seawater cooling systems/Ballast water systems/Fire main systems/General marine piping systems

They are especially suitable for vessels operating in harsh offshore or long-term seawater environments.

Compliance with Marine Standards

Butterfly valves equipped with C95400 bronze discs can be manufactured to meet the technical requirements of major marine classification societies, including ABS, DNV, CCS, and LR, ensuring acceptance by shipowners and shipyards worldwide.

Conclusion

Due to its excellent corrosion resistance, mechanical strength, and proven performance in seawater applications, C95400 aluminum bronze remains one of the preferred materials for butterfly valve discs in marine systems.

Tianjin Tanghai Dongyang Valve Co., Ltd. manufactures marine butterfly valves with C95400 bronze discs, offering reliable solutions for ABS, DNV, CCS, and LR certified marine projects.

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/double-flange-butterfly-valve-th-btv-df/

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!

Introduction of SS304 Disc for Concentric Type Butterfly Valve

The SS304 disc is one of the most commonly used materials for concentric type butterfly valves, offering an excellent balance of corrosion resistance, strength, and cost-effectiveness.

center-line butterfly valve plate disc parts (12)

center-line butterfly valve plate disc parts (12)

SS304 (AISI 304 / ASTM A351 CF8) is an austenitic stainless steel containing approximately 18% chromium and 8% nickel, which provides outstanding resistance to oxidation and a wide range of mild corrosive environments.

When used in concentric butterfly valves, the SS304 disc ensures:
Good corrosion resistance in air, water, and most neutral or mildly corrosive fluids.

High strength and durability, making it suitable for both industrial and marine applications.

Smooth surface finish, minimizing flow resistance and preventing medium buildup.

Compatibility with various seat materials (such as EPDM, NBR, or PTFE) for versatile service conditions.

Typical applications include water treatment, HVAC systems, general industry, shipbuilding, and chemical processes where moderate corrosion resistance is required.

C83600 Concentric Butterfly Valve Disc – Detailed Introduction

1. Material Description

C83600 belongs to Leaded Tin Bronze, one of the internationally recognized and widely used materials for marine valves.

Main Composition:

Copper (Cu): ~83%

Tin (Sn): ~7%

Lead (Pb): ~7%

Zinc (Zn): ~3%

Standards: Complies with ASTM B62, SAE 40

Material Properties:

High strength and toughness

Excellent corrosion resistance, especially suitable for seawater and salt spray environments

Superior casting performance and machinability

Good self-lubricating ability and excellent anti-galling performance

2. Advantages in Butterfly Valve Discs

Seawater Corrosion Resistance
C83600 maintains stable corrosion resistance in chloride-rich seawater, preventing pitting or dezincification of the disc.

Stable Sealing Performance
The disc has a high surface finish and good machinability, ensuring a precise fit with soft seats such as EPDM and NBR, and guaranteeing zero or minimal leakage.

Wear and Erosion Resistance
Under frequent operation or high-velocity seawater flow, discs made of C83600 offer long service life and are resistant to wear and erosion.

Excellent Castability and Machinability
Suitable for casting complex disc structures, with dense microstructure and high machining precision, ensuring overall valve performance.

High Reliability
Meets the requirements of classification societies such as ABS, LR, DNV, BV, and is widely used in marine systems.

3. Applications

C83600 discs are widely applied in concentric soft-seated butterfly valves for marine service, with typical applications including:

Ballast Water Systems

Seawater Cooling Systems

Fire-Fighting Piping Systems

Bilge, sewage, and seawater pipelines

4. Typical Properties

Property Value Range Remarks
Tensile Strength ≥ 250 MPa Ensures strength and load capacity
Yield Strength ≥ 100 MPa Resistant to deformation under load
Brinell Hardness (HB) 65 – 85 Balanced hardness for wear resistance and machinability
Elongation ≥ 10% Provides toughness and impact resistance
Density ~ 8.8 g/cm³ Dense and stable material structure
Corrosion Resistance Excellent Especially suitable for marine environments

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.

 

 

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