Lug type valves are provided with threaded bolting holes in accordance with API 594,ASTM,JIS,ISO.
Lug type has its own tapped holes which allow the bolts to be threaded into it from both sides. This allows the dismantling of any side of the piping system without removal of the duo check valve in addition to keeping the service on the other side.

Features

• Full Lug Lining design, mount between flanges by bolt which through disc and body.

Dual Plate Check Valve Installation Guide:

When installing a check valve, it can be used in both indoor and outdoor environments. However, if the medium is corrosive or the surroundings are prone to rust, it is essential to select a valve material combination that matches the conditions to ensure durability and safety. For special operating conditions, it is recommended to consult TVCCL’s technical team for professional advice.
Before installation, all debris, oxidation scale, and solid impurities inside the pipeline should be thoroughly removed to prevent interference with the valve’s operation. During installation, the flow direction of the medium must align with the arrow marked on the valve body. The piping should be aligned at the front and rear centers, with flange interfaces kept parallel and bolts evenly tightened. Special attention should be paid to the distance between the check valve and the pump, which should be six to eight times the valve size to ensure stable system performance.
For routine maintenance, regular inspections should be conducted to check for leakage, abnormal noise, or vibration. In addition, the valve should be periodically examined for signs of corrosion, jamming, or other irregularities. Necessary cleaning, dust removal, and residue treatment should be performed to maintain proper equipment operation and extend its service life.

Specification

• Size: 2" ~ 60" (DN50 - DN1500)
• Pressure Rating For ASME: 125# ~ 600# Suit For ASME / MSS / API Flange
• Pressure Rating For ISO: PN10 ~ PN40 Suit For ISO Flange
• Pressure Rating For JIS: 5K ~ 20K Suit For JIS Flange
• Material:CI,DI,WCB,CF8,CF8M,ALBC3,A8904A(MOQ)
• Designed in accordance with API 594.
• End Connection: Wafer (TC1), Lugged (TC7), Flanged (TC4)
• (Other flange connection please contact Taiwan Valves Centre Co., Ltd.)
• *Technical information is only for reference. Taiwan Valves Centre Co., Ltd. reserves the right to change without previous notice.

SELECTION GUIDE

1. Clarify Application Requirements and System Conditions
Begin by thoroughly assessing the environment in which the valve will operate. Key considerations include:
• Type of fluid — Is the medium water, oil, gas, slurry, or a corrosive chemical?
• Operating parameters — What are the system’s maximum pressure and temperature?
• Flow behavior — Is there a risk of sudden flow reversal or water hammer?
• Space limitations — Is the piping layout compact or spacious?
These factors help identify the most suitable valve materials and configurations for your system.
2. Select Materials Based on Fluid and Environment
The valve’s body and internal components must withstand corrosion and wear caused by both the fluid and the surrounding conditions. Common material choices include:
• Stainless steel — Excellent for corrosive or sanitary applications.
• Carbon steel or cast iron — Suitable for general-purpose use with non-aggressive media.
• PVC or engineered polymers — Ideal for low-pressure, non-corrosive systems.
Avoid incompatible combinations—such as using brass or mild steel with aggressive chemicals—as this may result in premature failure.
3. Choose the Correct Size and Pressure Rating
Valve sizing should align with the pipe diameter and expected flow rate:
• Proper sizing minimizes pressure drop and prevents turbulence.
• Ensure the valve’s pressure and temperature ratings exceed system requirements to maintain safety and reliability.
4. Evaluate Valve Dynamics and Performance Characteristics
Different wafer check valve designs offer distinct advantages depending on system demands:
• Spring-loaded or dual-plate wafer valves — Provide quick, silent closure to prevent water hammer in high-cycle operations.
• Standard single-plate models — Adequate for slow, steady flow in simpler systems

Seat Material Options for Dual Plate Check Valves

The seat of a dual plate check valve is available in a wide range of materials to meet various media properties, temperature ranges, and pressure conditions. Selecting the right seat material is essential to ensure reliable sealing performance, extended service life, and stable system operation.

Soft Seat Options:
Soft-seated designs provide excellent sealing performance and are typically made from rubber materials such as EPDM, NBR, or FKM (Viton®).

EPDM – Ideal for cooling water, potable water, and general water treatment applications.

NBR – Suitable for oils, air, and other neutral media.

FKM (Viton®) – Offers superior resistance to high temperatures and aggressive chemicals, making it ideal for chemical and petrochemical industries.

Metal Seat Options:
For high-temperature, high-pressure, or abrasive conditions, metal seats are recommended to ensure enhanced durability and wear resistance.
Metal seats can be manufactured from the same material as the valve body or from stainless steels such as SS304, SS316, SS410, or hard alloys like Stellite 6. The allowable leakage rate for metal seats varies depending on valve size.

For any special rubber material requirements, please feel free to contact us.

HEAD LOSS

Head loss refers to the loss of a fluid’s total energy (or pressure) as it flows through pipelines or valves, caused by factors such as friction, turbulence, changes in flow direction, and resistance within the flow path. In a dual-plate check valve, head loss is the pressure drop that occurs when the fluid passes through the valve plates and internal structure.

The smaller the head loss, the lower the resistance the fluid encounters when passing through the valve, the higher the flow efficiency, and the less energy is dissipated. This reduces the system’s pumping energy consumption and improves overall operational efficiency. Conversely, larger head loss indicates greater flow resistance and requires the pump to expend more power to maintain the desired flow rate. Therefore, analyzing head loss data is an important step in valve selection to ensure system efficiency, pressure control, and economic performance.

Dual Plate Wafer Type Check Valve Operation

When fluid flows in the forward direction, the pressure of the medium pushes the two plates open around the hinge pin, allowing smooth passage with minimal resistance. As the flow velocity decreases, the torsion springs automatically begin to act, gently returning the plates toward the body seats. This design minimizes the distance and time required for closure.
When flow reversal occurs, the plates are already near the seat, enabling the valve to close quickly and securely. This rapid dynamic response significantly reduces the water hammer effect, ensuring quiet, non-slam performance and protecting the system from pressure shock and vibration.

Advantages of Dual Plate Check Valves

Dual plate check valves offer several advantages that make them ideal for modern piping systems. Their compact and lightweight wafer design allows easy installation between flanges, saving both space and weight. The two spring-loaded plates close rapidly when flow decreases, effectively preventing backflow and minimizing water hammer.
Because of their simple structure and few internal components, dual plate check valves require minimal maintenance and provide reliable automatic operation without external power or manual control. They are available in a variety of materials and configurations, making them suitable for water treatment, HVAC, marine, power generation, and industrial fluid systems.

Functions of Dual Plate Check Valves

The primary function of a dual plate check valve is to prevent backflow and ensure that fluid flows in one direction only. Its two spring-loaded plates respond quickly to changes in flow, closing rapidly when flow reversal occurs to protect pumps, compressors, and other equipment from damage.
In addition to backflow prevention, dual plate check valves help maintain system pressure stability, minimize water hammer through non-slam operation, and improve overall energy efficiency. Their compact wafer-type design allows for easy installation and reliable performance across water treatment, HVAC, marine, power generation, and industrial pipeline systems.

Applications

• Soild Lug with full lining type check valve is suitable for sea water, cooling water..ext. Used in Ship Building, seawater desalination, seawater cooling system.
• Dual plate Full Lug type check valve is suitable for high temperature and high pressure environment, like Petrochemical, Refinery or power plant.
• Applied in Water Supply Systems, Fire Water Systems, Cooling Water, Chilled / Hot Water Systems, Boiler Feed Water, Sea Water, Potable Water, Raw Water etc.
• Suitable for gas, like LPG, LNG, Sour Gas Low Temperature, Cryogenic Applications
• Used in pharmaceutical, Power and other industries
• Solid lug type dual check valve can use for liquids and gasses in general services, on-/offshore applications, etc.
• In Nuclear Industry, Dual Check Valve used for feed water control system, make-up water or other.
• Also use in steam, oil, nitric acid, acetic acid, strong oxidizing medium and urea, different medium should chose different material.
• Full rubber type check valve suitable for seawater, water, cooling water pipeline and…etc.
• The full rubber lined usually used in shipyard, ship plant, seawater desalination, seawater-cooling system.
• The rubber separate medium and the valve of body in order not to contact directly. The full lining type check valve can be used for high concentration brine or acidic medium.
• Full lining type check valve widely applied for water conservancy facilities, sewage treatment plants, and industrial or residential construction industries.
• Dual plate wafer type check valve with full rubber can suitable for pump, sewerage, and reservoir flood control, etc.
• Used in waterproof systems, discharge system, pump, etc.

More Knowledge about TVCCL valve:

TVCCL full rubber type check valve’s material is divided into two choices, NBR and EPDM. Before use, you must pay attention to the temperature of the medium and whether there is a granular object in the medium. Because the rubber can't afford the high temperature and low temperature as well, it is recommended to use it at normal room temperature to avoid the rubber falling off or deforming; and owing to the rubber is unbearably worn, It is not recommended to use the full-rubber type check valve in the cement or the medium which has the presence of particulate matter in pipelines. The installation method is the same as the dual plate check valve. The only difference is that the flange surface of the full rubber type check valve is also covered with rubber, so it is not necessary to add a gasket to fix it.
The Full Rubber type check valve’s inner covering rubber, the medium and the body material are not in direct contact, and the rubber is separate into the medium and the valve body material, thereby achieving the acid resistance and corrosion resistance. The Full rubber type check valve body internal adopts an all-rubber design, which is not easily deposited or produced. And it also reduces the maintenance cost, but the disadvantage is that the rubber is not suitable to keep for a long-time in outside, even if the quality of the rubber is high, the aging phenomenon cannot be avoided.

More Knowledge about dual plate check valve:

Ductile iron, also known as ductile cast iron, ductile iron with the advantages of gray cast iron, and with a little steel advantages such as high strength, toughness, ductility, hardening, thermal workability, etc.…
Solid Lug Type check valve also called Full Lug type check valve. It is named the Lug type is because the shape is like the ear. Full Lug type is suitable for the environment where the space is small, because the flange hole has tapping, it can save the space occupied by the nut and the cost of the nut. Full Lug check valve has the same advantages and installation with Lug type, just the shape is different. Full Lug type Check valve is threaded (Flange holes by tapping). Also, after tapping the holes, it only needs the bolt to install, it can decrease the spent of Nuts on the contrary. Clamped between flanges with bolting passing through the body of a valve. The full lug type wafer type check valve's design that one end of the line can be taken off without having an effect on the opposing side. This can be executed by using flanges, along with two sets of lugs (bolts) that don't utilize nuts since each flange features its own bolts. It's also important to note that you don't need to shut down the entire system in order to clean, inspect, repair, or replace a lug wafer valve.

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TVCCL Valves Catalogue

Catalogue for TVCCL valves

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Dual Plate Wafer Style Check Valve Installation and Maintenance Instructions

Installation and Maintenance Instructions for dual plate check valve

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