Tag Archive for: valve seat

You are here: / / valve seat

Posts

Selection Standard and Application Analysis for Marine Valve

Choosing the right valves for marine systems is crucial to ensure safety, reliability, and long-term performance in harsh offshore environments. Key selection criteria include:

1.1 Material Selection

Preferred Material: SS316, Duplex Stainless Steel, Bronze

Reason: High corrosion resistance in seawater, brine, and aggressive chemicals

Tip: Avoid carbon steel for exposed or submerged applications

1.2 Valve Type Selection

Valve Type Typical Marine Application
Butterfly Valve Ballast systems, cooling water lines
Check Valve Pump discharge, bilge lines, fire systems
Gate Valve Seawater intake, cargo pipelines
Globe Valve Flow regulation in steam or fuel systems
Ball Valve Quick shut-off for fuel, oil, or air lines

1.3 Standards & Classification

Ensure compliance with IMO, IACS, and classification societies such as:

DNV, ABS, LR, BV, CCS

Check for Fire-Safe, DNV-GL approved, or ISO/ANSI certified valves where required

1.4 Functional Requirements

Operating pressure & temperature

Flow direction and velocity

Manual, pneumatic, or electric actuation

End connection (flanged, wafer, threaded)

2. Application Analysis – Where Marine Valves Are Used

2.1 Engine Room Systems

Seawater cooling lines

Fuel oil, lubricating oil pipelines

Steam and condensate systems

Bilge and ballast systems

 2.2 Deck Systems

Cargo handling valves

Firefighting systems

Air vent check valves for tanks

2.3 Underwater / Hull Applications

Seachests

Overboard discharge valves

Bottom inlet valves

Note: Corrosion resistance and class approval are critical here

3. Additional Recommendations

Use soft-sealing valves (e.g., EPDM-lined butterfly valves) for low-pressure, non-critical lines

Use metal-seated valves for high-temperature or abrasive media

Choose compact wafer-type valves to save space in narrow engine rooms

Plan for easy maintenance access, especially in engine room clusters

Ensure spare part availability for long-term operation at sea

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!

Common Faults and Maintenance of concentric Marine Butterfly Valves

Fault Cause Analysis Solution
Leakage Seat aging or wear Replace seat
Difficult operation Shaft rust or jamming Clean,lubricate,or replace shaft
Corrosion perforation Inadequate corrosion protection Repair by welding or replace valve
Handle damage Over-torque operation Replace handle and add torque limiter

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!

Anti-Corrosion Technology for Marine Concentric Butterfly Valves

Body Coating: Epoxy coating, thermal zinc spray, FBE coating.

Disc Protection: Stainless steel or copper alloy with surface treatment.

Seat Protection: Modified rubber for seawater resistance.

Shaft Sealing and Corrosion Prevention: Special coating in shaft sealing chamber + corrosion-resistant O-rings.

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!

Factors Affecting Sealing Performance of Concentric Soft Seal Butterfly Valves

Key Factors

  • Seat Material Selection: EPDM for seawater, NBR for oil, VITON for high temperature.
  • Machining Precision: Concentricity between valve body, disc, and seat.
  • Installation Position: Horizontal installation is preferred over vertical to avoid self-weight affecting sealing.
  • Torque Control: Excessive or insufficient torque may damage the seat.

Key Technical Points

  • Ensure concentricityamong body, disc, and seat.
  • Select suitable sealing materials.
  • Prevent high-temperature aging of the seat.
  • Apply anti-corrosion coatingsor linings to enhance seawater corrosion resistance.

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!

Comparison Between Concentric and Double Offset Marine Butterfly Valves

Item Concentric Butterfly Valve Double Offset Butterfly Valve
Structure Disc center aligned with body centerline Disc center offset from body centerline
Sealing Type Mainly soft seal Soft+hard seal available
Operation Torque Low Slightly higher
ApplicationPressure Low to medium pressure(PN6-PN16) High pressure(PN25-PN40)
Cost Lower Higher
Typical Application General ship pipelines,ballast water systems High-ressure fire system,deck wash system

 

 

triple eccentric butterfly valve-wafer-butt weld (1)

Centerline butterfly valves are more economical and suitable for general marine pipelines, while double offset valves are better for high pressure, high temperature, or special media.

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.

Butterfly Valve Connection Standard

Butterfly valves are widely used in industrial applications for regulating flow and are manufactured according to several connection standards. These standards ensure compatibility, safety, and reliability. Below are the common connection standards for butterfly valves:

1. Flanged Connections

Butterfly valves with flanged ends are designed to mate with standard pipe flanges. The key standards for flanged connections include:

  • ASME B16.5: Pipe Flanges and Flanged Fittings (covers sizes from ½ inch to 24 inches, pressure classes 150 to 2500).
  • EN 1092-1: Flanges and their joints for PN-designated pressure systems.
  • ISO 7005-1: Metallic flanges for general purposes.
  • JIS B2220: Japanese flange standard.

2. Wafer Type Connections

Wafer butterfly valves are designed to fit between two pipe flanges using bolts or studs.

  • They are typically compatible with flange drilling patterns as per:
    • ASME B16.5
    • EN 1092
    • ISO 7005

3. Lug Type Connections

Lug butterfly valves have threaded inserts that allow them to be bolted to a pipe flange. Standards include:

  • ASME B16.5
  • EN 1092
  • ISO 7005

4. Grooved End Connections

For quick installation and connection to grooved piping systems.

  • AWWA C606: Grooved and shouldered joints.

5. Butt-Weld Connections

Less common for butterfly valves but occasionally used in specific applications.

  • ASME B16.25: Butt-welding ends.
  • ISO 9692: Welding preparation standards.

6. Standards for Specialized Applications

  • AWWA C504: For waterworks applications, especially large-diameter valves.
  • API 609: Butterfly valves for general-purpose applications.
  • MSS SP-67: Covers butterfly valves, general-purpose and high-performance types.

Key Considerations

  • Always ensure that the valve and mating components meet the same flange drilling patterns and pressure ratings.
  • Verify that the material of construction and dimensions meet the system’s operational requirements (temperature, pressure, medium compatibility).

Let us know if you’d like details on a specific standard!

The Valve Disc Material of Concentric Type Butterfly Valve

The common valve disc materials for middle-line butterfly valves are as follows, with each material suitable for different working environments and media:

Ductile Iron: Known for its good strength, toughness, and impact resistance, ductile iron is commonly used in general industrial applications involving media such as water and gas. It is cost-effective, but its corrosion resistance is relatively poor.

304 Stainless Steel: A widely used stainless steel material, 304 offers good corrosion resistance and is suitable for less aggressive corrosive media, such as water, air, and oil.

316 Stainless Steel: Compared to 304, 316 stainless steel offers better corrosion resistance, especially in environments with more aggressive media like seawater, acidic substances, or saltwater.

C95400 Aluminum Bronze: This material provides excellent corrosion resistance, wear resistance, and mechanical strength, and is widely used in marine, shipbuilding, and chemical industries. It is suitable for highly corrosive media such as seawater and saltwater.

C95800 Aluminum Bronze: With higher strength and enhanced corrosion resistance, C95800 is particularly suitable for marine environments and applications involving corrosive media like acids and chlorides.

These materials are selected based on specific application requirements such as temperature, pressure, and the corrosiveness of the media, ensuring the most suitable valve disc material for optimal performance.

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!

Corrosion Resistance of Marine Butterfly Valves

The corrosion resistance of marine butterfly valves is a critical factor in their selection and application, especially in marine environments. Due to the presence of salt spray, high humidity, and seawater’s corrosive nature, marine equipment requires superior corrosion-resistant properties. Below are key aspects related to the corrosion resistance of marine butterfly valves:

1. Material Selection

Material plays a crucial role in determining the corrosion resistance of marine butterfly valves. Common materials include:

  • Stainless Steel(e.g., 316, 316L): Offers excellent resistance to corrosion and is suitable for saltwater and corrosive chemical media.
  • Bronze: Resists saltwater corrosion and is commonly used in seawater piping systems.
  • Duplex Stainless Steel: Combines high strength with resistance to pitting and crevice corrosion, making it ideal for harsh marine environments.
  • Plastic Linings(e.g., PTFE, PVDF): Plastic-lined valves enhance corrosion resistance, making them suitable for handling highly corrosive media.

2. Coating and Protection

Marine butterfly valves often feature coatings or surface treatments to improve corrosion resistance:

  • Epoxy Coatings: Enhance resistance to corrosion, particularly in seawater contact areas.
  • Thermal Spray Coatings: Application of corrosion-resistant alloys (e.g., nickel-based alloys) provides additional protection.
  • Anodizing(for aluminum alloys): Improves surface hardness and resistance to oxidation.

3. Design Features

  • Seal Material Selection: Resistant materials such as EPDM or fluororubber are often used for seals to prevent failures due to corrosion.
  • Optimized Structure: Minimizing gaps and dead zones reduces the accumulation of corrosive substances.

4. Environmental Impact

  • In marine environments, salt spray and electrochemical corrosion require special attention to pitting and crevice corrosion resistance.
  • For valves submerged in seawater for extended periods, electrochemical corrosion prevention methods such as cathodic protection are essential.

5. Standards and Certifications

The materials and corrosion resistance of marine butterfly valves must comply with international or industry standards, such as:

  • ISO 15156(Standards for materials resistant to sulfide stress corrosion).
  • DNV GL, ABS, BV Certifications: International classification societies impose stringent requirements for corrosion protection in marine equipment.

6. Maintenance and Care

Regular inspection and cleaning of the valve surface, along with timely replenishment or replacement of coatings, can effectively extend the service life of marine butterfly valves.

In summary, the corrosion resistance of marine butterfly valves depends primarily on material selection, surface treatment technologies, and appropriate adaptation to specific environmental conditions. During design and selection, it is crucial to consider factors such as media properties, operating temperature, and pressure comprehensively.

Shaft Materials in Marine Valve

Shafts in marine valves are critical components that connect the actuator or handwheel to the valve’s internal components, allowing for control of fluid flow. The material selection for marine valve shafts depends on the application, operating environment, and fluid type. Common shaft materials in marine valve applications include:

1. Stainless Steels

  • Grade 316/316L:
    • High corrosion resistance, particularly against seawater and marine atmospheres.
    • Suitable for most marine applications, including those handling water, oils, and certain chemicals.
  • Duplex Stainless Steels (e.g., 2205):
    • High strength and superior corrosion resistance.
    • Excellent performance in environments with high chloride concentrations (e.g., seawater).
  • Super Duplex Stainless Steel (e.g., 2507):
    • For highly aggressive environments, including high-pressure seawater systems.

2. Bronze and Brass Alloys

  • Aluminum Bronze (e.g., C95400, C95800):
    • Excellent resistance to marine corrosion and biofouling.
    • Commonly used in seawater applications.
  • Nickel-Aluminum Bronze:
    • Provides higher strength and wear resistance.
    • Often used in valves for seawater and hydraulic systems.

3. Monel (Alloy 400)

  • High resistance to corrosion, particularly in saltwater and acidic conditions.
  • Ideal for highly corrosive environments, including marine chemical systems.

4. Hastelloy (e.g., C276, C22)

  • Exceptional resistance to chemical corrosion.
  • Used in marine environments with aggressive chemicals or extreme conditions.

5. Titanium

  • Excellent resistance to seawater corrosion and lightweight.
  • Used in specialized, high-performance applications (e.g., submarines, desalination systems).

6. Carbon Steel (with coatings)

  • Less expensive but requires protective coatings (e.g., epoxy, galvanizing) to prevent corrosion in marine environments.
  • Typically used in less demanding applications.

7. Nickel Alloys

  • Provides excellent resistance to oxidation and chloride-induced corrosion.
  • Often used in valves for extreme marine environments.

Material Selection Factors:

  • Corrosion Resistance: Seawater and chlorides are particularly aggressive.
  • Strength and Durability: High-pressure systems require stronger materials.
  • Temperature Resistance: Some applications involve elevated temperatures.
  • Chemical Compatibility: Fluids handled by the valve may demand specific material compatibility.
  • Cost: Balancing performance with budget constraints.

When designing or selecting shafts for marine valves, proper consideration of operating conditions and regulatory standards (e.g., ABS, DNV, or IMO) is crucial to ensure reliability and compliance.

Application of Concentric type Resilient Seated Butterfly Valve in Marine Vessel

Concentric type resilient seated butterfly valves are commonly used in marine vessels for several reasons:

Leakage Prevention: The resilient seat provides a tight seal, reducing the risk of leakage in critical applications. This is crucial in marine environments where leaks can lead to significant safety and operational issues.

Corrosion Resistance: These valves are often made from materials that resist corrosion, which is essential for marine applications due to the harsh saltwater environment.

Compact Design: The concentric design allows for a compact and lightweight valve, which is beneficial in the space-constrained environment of a marine vessel.

Ease of Operation: These valves generally have a simple design that makes them easy to operate, which is important for maintaining efficient and reliable operation on a vessel.

Flow Control: They provide effective flow control, which is necessary for managing various systems on a marine vessel, such as cooling systems, ballast systems, and fuel systems.

Maintenance: The design typically allows for easier maintenance and replacement, which is advantageous for keeping the vessel in good working condition.

The concentric type resilient seated butterfly valve is valued in marine applications for its reliability, resistance to corrosion, and ease of maintenance, all of which contribute to the safe and efficient operation of marine vessels.

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!

TH VALVE • PROFESSIONAL VALVE MANUFACTURER

GET IN TOUCH WITH US

Cell: 0086-185 2639 6136
0086-133 7031 7626
E-mail: tanghai@tanghaivalve.com
info@tanghaivalve.com
Web: www.tanghaivalve.com
Add: East of Guanghui Road, Beizhakou town, Jinnan District, Tianjin, P.R.China.

© Copyright 2020 Tianjin Tanghaidongyang Valve Co., Ltd. All Rights Reserved.
Top Valve Manufacturer, Provide the best solutions for valve projects.