AILAN Tech

Dual Plates Wafer Check Valve

A compact and lightweight non-return valve designed for installation between flanges, featuring two spring-loaded discs that swing open to allow forward flow and close instantly to prevent backflow.

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DIN Resilient Seated NRS Gate Valve

Product Overview

The Dual Plate Wafer Check Valve is engineered for space-saving installations in pipeline systems where minimal pressure drop and reliable non-return performance are critical. Its unique design features two hinged discs that swing open when flow passes in the forward direction, and close automatically when flow reverses, preventing backflow and protecting pumps, compressors, and other equipment.

Constructed from high-quality materials such as ductile iron, carbon steel, or stainless steel, the valve offers excellent corrosion resistance and durability. The discs are typically made of stainless steel with resilient seating materials like PTFE or EPDM, ensuring tight shutoff even at low pressures.

With its wafer-style design, the valve is installed between two pipe flanges without the need for additional bolts or nuts, making it easy to install and maintain. It is suitable for a wide range of applications, including water treatment, HVAC, oil and gas, chemical processing, and power generation.

Key Features & Benefits

Dual Disc Design

Two spring-loaded discs provide quick and reliable closure, minimizing water hammer and ensuring bubble-tight shutoff.

Lightweight & Compact

Wafer-style design reduces installation space and weight compared to traditional swing check valves.

Low Pressure Drop

Streamlined flow path minimizes pressure loss, improving system efficiency and reducing energy costs.

Corrosion Resistance

Available in a range of materials including stainless steel and Hastelloy for compatibility with aggressive media.

Easy Maintenance

Simple construction allows for easy inspection and replacement of discs and seats without removing the valve from the pipeline.

Wide Application Range

Suitable for use in water, oil, gas, steam, and chemical applications across various industries.

Technical Specifications

Basic Parameters

Parameter Specification Range
Nominal Diameter (DN) 15mm ~ 1200mm
Pressure Class 150 LB, 300 LB, PN10, PN16, PN25, PN40
Operating Temperature -20°C ~ 425°C (Depending on material)
Applicable Media Water, Oil, Gas, Steam, Chemicals
Sealing Class API 598 Class VI, ISO 5208 Class 1

Material Specifications

Component Material Options Standards/Features
Body Ductile Iron, Carbon Steel, Stainless Steel ASTM A536, ASTM A216 WCB, ASTM A351 CF8/CF8M
Disc Stainless Steel, Hastelloy ASTM A182 F304/F316, Hastelloy C276
Seat Resilient Polymers, Metal PTFE, EPDM, Viton, Stellite
Spring Stainless Steel Inconel X-750, Hastelloy
End Connection Wafer, Lug ASME B16.5, EN 1092-1

Standards & Compliance

  • Design Standards: API 594, ISO 10434
  • Face-to-Face Dimensions: API 594, ISO 5752
  • Flange Standards: ASME B16.5, EN 1092-1
  • Testing Standards: API 598, ISO 5208
  • Certifications: CE, API 6D, ISO 9001

Working Principle

The Dual Plate Wafer Check Valve operates on a simple yet effective mechanism to control fluid flow:

  1. Open Position: When fluid flows in the forward direction, the pressure pushes the two discs open, allowing unobstructed flow through the valve.
  2. Closing Action: When flow reverses, the spring force and backflow pressure cause the discs to swing closed, preventing reverse flow.
  3. Sealing Mechanism: The resilient seats on the discs compress against the valve body, creating a tight seal that prevents leakage even at low pressures.
  4. Water Hammer Prevention: The quick closure of the discs minimizes water hammer, reducing the risk of damage to the pipeline and equipment.

Application Areas

Water Treatment

Used in water treatment plants, distribution networks, and wastewater systems to prevent backflow and protect pumps.

HVAC Systems

Ideal for heating, ventilation, and air conditioning systems to maintain proper flow direction and prevent system damage.

Oil & Gas Industry

Suitable for use in oil and gas pipelines, refineries, and petrochemical plants to prevent backflow and ensure system integrity.

Chemical Processing

Used in chemical plants to handle corrosive and aggressive fluids, ensuring safe and reliable operation.

Power Generation

Ideal for use in power plants, including thermal, nuclear, and renewable energy facilities, to protect turbines and other equipment.

General Industry

Suitable for a wide range of industrial applications, including manufacturing, mining, and food processing.

Installation & Maintenance

Installation Guidelines

  • Ensure the valve is installed in the correct orientation with the flow direction arrow on the body pointing in the direction of flow.
  • Clean the pipeline and remove any debris before installation to prevent damage to the valve internals.
  • Install the valve between two flanges using appropriate gaskets and bolts. Tighten the bolts evenly in a crisscross pattern to the recommended torque.
  • For horizontal installations, mount the valve with the hinge pin in the horizontal position. For vertical installations, ensure the flow is upward.
  • Do not use the valve as a support for the pipeline. Provide adequate support to prevent stress on the valve body.
  • Perform a leak test after installation to ensure proper sealing.

Maintenance Recommendations

  • Inspect the valve regularly for signs of wear, corrosion, or leakage. Replace any damaged components as needed.
  • Lubricate the hinge pins and springs periodically to ensure smooth operation.
  • Clean the valve internals if there is a buildup of debris or scale that could affect performance.
  • Check the disc alignment and seating to ensure proper closure. Adjust or replace the discs and seats if necessary.
  • Keep records of maintenance activities and replacement parts for future reference.

Frequently Asked Questions (FAQ)

Q: What is the difference between a dual plate wafer check valve and a swing check valve?

A: Dual plate wafer check valves are more compact and lightweight than swing check valves, with a lower pressure drop. They also close more quickly, reducing the risk of water hammer. Swing check valves are better suited for larger diameters and higher flow rates.

Q: Can dual plate wafer check valves be used for steam applications?

A: Yes, dual plate wafer check valves can be used for steam applications, but they must be made of materials suitable for high temperatures and pressures. It is important to select the correct seat material (e.g., metal or high-temperature polymer) for the specific steam service conditions.

Q: How do I select the right size dual plate wafer check valve for my application?

A: The size of the valve should be based on the nominal diameter (DN) of the pipeline and the flow rate. It is also important to consider the pressure rating and temperature of the application to ensure the valve can handle the operating conditions.

Q: Are dual plate wafer check valves suitable for vacuum applications?

A: Dual plate wafer check valves are not typically recommended for vacuum applications, as the spring force may not be sufficient to keep the discs closed against a vacuum. For vacuum service, a specialized check valve designed for low-pressure conditions should be used.

Q: Can dual plate wafer check valves be installed in any orientation?

A: Dual plate wafer check valves are designed to be installed in horizontal pipelines with the hinge pin in the horizontal position. They can also be installed in vertical pipelines with upward flow, but downward flow is not recommended as it may affect the closing performance.

Need Custom Solutions?

Our engineering team can customize Dual Plates Wafer Check Valves to meet your specific pressure, temperature, and media requirements. Contact us today for a personalized quote.

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