Relay Valve

Your Professional Relay Valve Supplier

Our goal is to become your true partner in the field of air dryer in China. Zhuji Bangna Auto Parts Co., Ltd is a factory specializing in clutch booster and air dryer in Zhuji. We can provide supporting services to customers. Our company is committed to applying advanced manufacturing technology and strict quality control standards to every product. The price is competitive and the product is quality-assured, which is a good choice for your long-term cooperation.

Why Choose Us

Production Equipment

Our company's equipment includes precision machining center, bench drilling machine, pneumatic test lathe, hydraulic test lathe, CNC machine tools, die casting machine, etc.

Our Certificate

Our products strictly comply with relevant standards and have passed TS16949:2009 certification.

Production Market

Our products are very popular in the market, and the main sales areas of our products involve domestic and foreign markets, such as Russia, Dubai in the Middle East, Saudi Arabia, Iran, Turkey, India, Africa, etc.

Our Service

The company has a professional sales team to provide you with high-quality pre-sales consulting services. During the order production process, customers can communicate with us at any time to understand the production progress. At the same time, we provide high-quality after-sales service to meet the different needs of customers.

Advantages of Relay Valve

‌Shorten brake reaction time

The relay valve can quickly deliver compressed air in the air reservoir to the brake air chamber, thereby significantly shortening the brake reaction time and enhancing the braking effect‌.

‌Enhanced braking effect

The relay valve quickly transmits compressed air to enable the brake shoe or brake disc to quickly generate braking force, effectively reducing the vehicle speed.

‌Preventing overload of mechanical transmission components

The relay valve can prevent the driving and parking systems from operating at the same time, avoiding the overlap of forces in the combined spring brake cylinder and the spring brake chamber, thereby preventing the mechanical transmission components from overloading and causing the spring brake to fail. Rapid filling and exhaust of the cylinder.

‌Improve the sensitivity and reliability of the braking system

Compared with traditional braking methods, the relay valve reduces the braking response time and improves the sensitivity and reliability of braking‌.

Technical Parameters of Relay Valve

Port Thread 1	M22 x 1.5
Port Thread 2	M22 x 1.5
Port Thread 3	Drain
Port Thread 4	M22 x 1.5
Size (mm x mm x mm)	104 x 100 x 105

Types of Relay Valve

Service brake relay valve

With a service brake relay valve installed, the hose that connects to the primary delivery-port output of the foot-valve becomes a control-line.

Spring brake relay valve

A spring brake relay valve works on the same principle as the service brake relay valve, although it has the opposite effect. This type of relay valve responds to a major drop in pressure at its control-port by opening its exhaust port, which causes the air from each spring brake chamber under its control to remotely exhaust, thus applying the spring brakes much-more-quickly than would otherwise be possible if the air were required to discharge via the yellow parking-control valve on the dashboard.

Applications of Relay Valve

Such as in trailer or semi-trailer braking systems. In the braking system of the truck, the relay valve plays the role of shortening the reaction time and the pressure build-up time. Generally, a differential relay valve is used. To prevent the simultaneous operation of the driving and parking systems, the combined spring brake cylinder and the force in the spring brake chamber overlap, so as to avoid the overload of the mechanical transmission element, so that the spring brake cylinder can be quickly charged and exhausted.

Material of Relay Valve

Typically made of cast aluminum, brass, or steel for durability and corrosion resistance. Seals: Rubber or synthetic materials like nitrile or EPDM. Springs: High-grade steel for flexibility and strength. Diaphragms: Elastomers designed to withstand high-pressure air.

Production Process of Relay Valve

Design: Engineers create detailed cad models based on the functional requirements, including pressure rating, material, and durability.

Prototyping: 3D printing or cnc machining is used to create prototypes for performance testing.

Casting/forging: The valve body is cast or forged from the chosen material.

Machining: Cnc machining ensures precise dimensions for components like ports, bores, and mounting points.

Spring Manufacturing: Springs are fabricated using coiling machines and heat-treated for strength and longevity.

Seal/diaphragm molding

Rubber seals and diaphragms are molded using injection or compression molding techniques.

Sub-assembly

Internal components (e.G., springs, diaphragms, pistons) are pre-assembled into functional units.

Final assembly

The valve housing is combined with sub-assemblies, and fasteners are torqued to specifications.

Precautions for Use Relay Valve

For relay valves, the stability of the electrical connection is crucial. Regularly check the cables, joints and connectors to ensure that there is no looseness, corrosion or wear. Performing functional tests is an important way to verify the performance of the relay valve. Regularly verify the switching status, response time and flow control capability of the relay valve through manual operation or automated test equipment. If an abnormality is found during the test, it is necessary to repair or replace it in time to ensure the reliability of the system.

Quality Testing of Our Relay Valve

Leak testing

Valves are tested under pressurized conditions to ensure airtight seals.

Functional testing

The relay valve is tested for proper operation, including response time and pressure regulation.

Durability testing

Components are subjected to cyclic loads to evaluate longevity.

Surface Treatment of Relay Valve

Coating

Anti-corrosion coatings like anodizing, powder coating, or electroplating are applied to the housing.

Marking

Product identification, including serial numbers and specifications, is laser-etched or stamped.

Packaging and Shipping of Relay Valve

Packing	Plastic bags, cartons, racks, plywood cases etc.
Shipping	Shipping, air flight, international express etc.

Other Service of Relay Valve

Branded packaging	We can provide packaging and customize products according to customer needs.
Delivery time	The order will be arranged for production after receiving the deposit. The delivery time of conventional neutral packaging products is within 20-40 days. The specific time will be determined according to the product quantity and packaging requirements.

FAQ

Q: What does a relay valve do?

A: A relay valve is an air-operated valve typically used in air brake systems to remotely control the brakes at the rear of a heavy truck or semi-trailer in a tractor-trailer combination.

Q: What is the difference between a quick release valve and a relay valve?

A: Quick Release Valves: These valves allow air to quickly escape from the brake chambers when the brakes are released, which allows for faster brake release times and better performance. Relay Valves: These valves are used in dual-circuit air brake systems to proportion the air pressure between the two circuits.

Q: Which is the purpose of relay relief valves?

A: Pressure relief valves reduce the possibility of damage to the pump and other water supply components that may be caused by water hammer when valves are operated too quickly or: intake pressures rise dramatically.

Q: Which line activates the relay valve?

A: The air line from the foot valve to the relay valve now becomes a control line that signals to the relay valve the amount of air to be drawn from the service reservoir for faster application of the brakes. A quick-release valve is built in for faster release of the brakes.

Q: Where is the relay valve?

A: The relay valve in an air brake system functions as a relay station to speed up the application and release of the brakes. The valve is normally mounted at the rear of the vehicle in proximity to the chamber it serves.

Q: What do inline relay valves allow for?

A: An inline relay operation using a four-way hydrant valve is the key. This method allows firefighters to maintain uninterrupted water flow while adding pumpers to boost pressure as needed.

Q: What is the crack pressure of a relay valve?

A: The crack pressure is located on a tag or plate. A designation of RV040 designates a relay valve with a nominal crack pressure of 4.0 psi. Using a different crack pressure relay valve may cause a change in braking characteristics. A typical crack pressure is 4.0 psi.

Q: What does the quick release feature of a relay valve allow for?

A: The function of a quick-release valve (Fig. 23) is to rapidly exhaust air from the controlled device. It is normally located adjacent to the controlled device, rather than requiring exhaust air to return and exhaust through the control valve. This decreases release time.

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