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!
© Copyright 2020 Tianjin Tanghaidongyang Valve Co., Ltd. All Rights Reserved.
How to Choose Butterfly Valves for Seawater Systems
Selecting the right butterfly valve for seawater systems is essential to ensure long-term reliability, corrosion resistance, and safe operation in marine applications. Seawater presents unique challenges due to its corrosive nature and continuous exposure to harsh operating conditions.
1. Material Selection
Material choice is the most critical factor for seawater systems. Components in direct contact with seawater must provide excellent corrosion resistance.
Commonly recommended materials include:
Bronze (e.g. C95400 aluminum bronze) for valve discs
Ductile iron or carbon steel bodies with suitable coatings
Stainless steel or corrosion-resistant alloys for shaft
Using improper materials may lead to corrosion, leakage, and premature valve failure.
2. Valve Seat Design
Both soft seated and metal seated butterfly valves can be used in seawater systems, depending on operating conditions.
Soft seated valves provide excellent sealing performance and are suitable for most seawater cooling and ballast systems.
Metal seated valves are preferred for higher temperatures or severe service conditions.
The correct seat selection improves sealing reliability and extends service life.
3. Pressure and Temperature Ratings
Seawater systems operate under different pressure and temperature conditions depending on vessel type and system design. Butterfly valves must be selected with appropriate pressure ratings to ensure safe operation.
Always verify:
Design pressure/Operating temperature/Applicable marine standards
4. Compliance with Marine Classification Requirements
For shipbuilding projects, butterfly valves must meet the requirements of marine classification societies such as ABS, DNV, CCS, and LR.
Valves should be supplied with:
Material traceability/Pressure test records/Inspection and certification documents
This ensures smooth approval during vessel construction and commissioning.
5. Manufacturer Experience and Quality Control
Choosing an experienced marine valve manufacturer is as important as selecting the valve itself. Manufacturers with marine application experience understand classification rules, seawater corrosion challenges, and quality control requirements.
Working with a reliable manufacturer reduces project risk and ensures consistent product quality.
Conclusion
Proper selection of butterfly valves for seawater systems requires careful consideration of materials, seat design, operating conditions, and certification requirements. A well-selected valve improves system reliability, reduces maintenance costs, and ensures long-term marine performance.
Tianjin Tanghai Dongyang Valve Co., Ltd. manufactures marine butterfly valves designed for seawater systems, with materials and designs suitable for ABS, DNV, CCS, and LR certified 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/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!
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.
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.
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!
Why Bronze Butterfly Valves Are Widely Used in Marine Applications
Bronze butterfly valves are widely used in marine and shipbuilding applications due to their excellent corrosion resistance, mechanical stability, and long service life in seawater environments.
Excellent Corrosion Resistance in Seawater
Marine piping systems are continuously exposed to seawater, salt spray, and humid conditions. Bronze alloys, especially aluminum bronze materials such as C95400, offer outstanding resistance to seawater corrosion, dezincification, and biofouling. This makes bronze butterfly valves a reliable choice for long-term marine service.
Reliable Performance for Marine Systems
Bronze butterfly valves are commonly applied in:
Seawater cooling systems/Ballast water systems/Firefighting systems/General marine piping systems
Compared with carbon steel or cast iron, bronze components maintain stable mechanical properties and sealing performance under harsh marine conditions, reducing the risk of leakage and premature failure.
Compatibility with Marine Classification Requirements
For shipowners and shipyards, compliance with classification society rules is essential. Bronze butterfly valves can be manufactured to meet the requirements of major marine classification societies such as ABS, DNV, CCS, and LR, ensuring safety and regulatory acceptance for marine projects.
Long Service Life and Lower Maintenance Cost
Although bronze butterfly valves may have a higher initial cost than standard materials, their superior corrosion resistance significantly reduces maintenance frequency and replacement costs over the vessel’s service life. This makes them a cost-effective solution for marine operators.
Conclusion
Due to their corrosion resistance, reliability, and compliance with marine standards, bronze butterfly valves remain one of the preferred valve solutions for marine and shipbuilding 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/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!
Marine Bronze Butterfly Valve
Certified Reliability for Marine & Offshore Applications
The Marine Bronze Butterfly Valve is specially engineered for shipboard and marine piping systems, where long-term reliability and corrosion resistance are essential. Manufactured from high-quality bronze or aluminum bronze alloys, this valve delivers excellent performance in seawater, salt spray, and harsh marine environments.
With a compact structure and quick quarter-turn operation, it is an ideal solution for both on/off service and flow regulation in marine applications.
Key Advantages
Outstanding Seawater Corrosion Resistance
Marine-grade bronze and aluminum bronze materials provide excellent resistance to seawater corrosion, erosion, and biofouling, ensuring long service life in demanding marine conditions.
Compact & Lightweight Design
The butterfly valve design minimizes weight and installation space, making it especially suitable for shipboard systems with limited space.
Quick & Efficient Operation
A 90° quarter-turn mechanism allows fast opening and closing, improving operational efficiency and system response.
Flexible Installation Options
Available in wafer, lug, and flanged types, compatible with various marine piping standards.
Multiple Actuation Options
Manual lever, worm gear, pneumatic, or electric actuators are available to meet different operating and automation requirements.
Classification Society Approval Available
The Marine Bronze Butterfly Valve can be supplied with classification society certification, including:
ABS (American Bureau of Shipping)/DNV (DNV – Maritime & Offshore)
CCS (China Classification Society)/LR / LRS (Lloyd’s Register)
Certification can be provided according to project or shipowner requirements, ensuring full compliance with international marine standards.
Typical Marine Applications
Seawater cooling systems/Ballast water systems/Fire-fighting pipelines
Freshwater and service water systems/Offshore and marine auxiliary systems
Widely used on commercial vessels, offshore platforms, and marine engineering projects.
Materials & Specifications (Typical)
Body / Disc: Bronze or Aluminum Bronze (e.g. C95400, C95800)
Stem: Stainless steel or corrosion-resistant alloy/Seat: EPDM, NBR, PTFE
Size Range: DN40 – DN1200 (1½″ – 48″)/Pressure Rating: PN6 – PN16 / ANSI Class 125 – 150
Operation: Lever, Gear, Pneumatic, Electric
Other materials and configurations are available upon request.
A Trusted Choice for Marine Service
Combining marine-grade materials, flexible certification options, and reliable performance, the Marine Bronze Butterfly Valve is a proven solution for shipowners and marine engineers seeking durability, safety, and long-term value.
U-Type Marine Concentric Butterfly Valve Introduction
1. Overview
The U-type marine concentric butterfly valve is a wafer-style soft-seated valve designed for shipboard piping systems.
Featuring a U-shaped body groove and a concentric disc-shaft structure, the valve provides reliable shut-off performance, excellent corrosion resistance, and easy installation with marine-standard flanges.
It is widely used for seawater, cooling water, ballast water, fire-fighting, and various utility lines on vessels.
Concentric Structure (Center-Line Design)
The disc and shaft share the same centerline, providing stable torque, low operating resistance, and tight shut-off.
U-shaped Groove Body
Ensures accurate alignment with JIS / DIN / ANSI marine flanges and enhances sealing integrity.
Soft Seat Sealing
EPDM, NBR, PTFE, or Viton seats deliver excellent sealing performance and low leakage (Bubble-Tight).
Lightweight & Space-Saving
Compact body design is ideal for marine engine rooms and confined piping spaces.
Quick Operation
90° rotation with lever, gear operator, pneumatic actuator, or electric actuator.
Excellent Corrosion Resistance
Common marine materials such as C95400, C95800, CF8M, and duplex stainless steel ensure long service life in seawater applications.
3. Typical Materials
Body: Aluminum Bronze C95400 / C95800/Stainless Steel CF8 / CF8M
Duplex Stainless Steel S31803 / S32750/Ductile Iron with marine epoxy or rubber lining
Disc: C95400 / C95800 / SS316 / SS316L/Duplex Stainless Steel/Ni-plated Ductile Iron
Shaft： SS316/Duplex Steel
Seat: EPDM (recommended for seawater)/NBR (for oil-related media)/PTFE (for corrosive chemical media)/Viton (for high temperature or special fluids)
4. Applications
U-type concentric butterfly valves are commonly used in:
Seawater cooling systems，Ballast water pipelines，Engine room and machinery space piping，Fire-fighting lines，HVAC systems，Fresh water and utility pipelines
Water treatment and bilge systems
5. Applicable Standards
Marine Class Approvals: DNV / ABS / LR / BV / NK / RINA
Face-to-Face: ISO 5752 / EN 558
Flanges: JIS 5K/10K, DIN PN10/16, ANSI Class 150
Actuator Mounting: ISO 5211
Available with EN 10204 3.1 / 3.2 Certificates
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)
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.
Full Lined PTFE Butterfly Valve
What is a Full Lined PTFE Butterfly Valve?
A full-lined PTFE butterfly valve is a butterfly valve whose wetted (fluid-contact) surfaces (body interior + disc / plate + sometimes stem bushing, etc.) are fully lined with PTFE (Polytetrafluoroethylene) or a similar chemically inert fluoropolymer. The lining protects the metal against corrosion and chemical attack. Useful for acids, alkalis, aggressive chemicals, etc.
Key features often include:
Full PTFE lining: Body & disc (sometimes liner also for shaft sealing) so that the medium does not contact the metallic parts.
Valve types: Wafer, Lug, Flanged, split-body, two-piece body, etc.
Pressure ratings: Commonly PN10, PN16, ANSI 150 / Class 150, sometimes lower / higher depending on size & design.
Size range: From small (DN50 / 2″) up to large (DN600, DN1200 etc) depending on manufacturer.
Temperature range: Depends on PTFE and other materials. Usually −20°C up to about +150°C (sometimes more, sometimes less).
Body and disc materials: Stainless steel, cast iron, ductile iron, carbon steel, etc, but protected by the PTFE lining.
Pros & Cons
What to Check / Ask For When Buying
If you are selecting a supplier or model, consider:
1.Lining quality & method
How is the PTFE liner attached (bonded, mechanically fixed)?
Is the disc also lined or just the body?
2.Pressure & temperature ratings
At your operating temperature & pressure, is the PTFE specification valid? (PTFE has limits).
Overpressure, vacuum capability.
3.Standards & test certificates
Compliance: API609, EN593, EN12266, ISO5752, ANSI, etc.
Leakage class, tightness tests.
4.Connection type
Wafer, lug, flange types. Which suits your piping system.
5.Actuation
Manual lever, gear, pneumatic, electric. Torque required (PTFE adds friction sometimes).
6.Maintenance
Can the liner/disc be replaced or serviced? Spare parts available.
Expected lifetime under your fluid & environment.
7.Chemical compatibility
The specific chemicals, concentration, temperature, etc. Make sure PTFE is compatible.