Double Ball Air Release Valve

The Double Ball Air Release Valve from FYL is a high-performance air valve designed for water pipelines requiring reliable gas discharge, negative pressure protection, and energy-efficient operation. As a professional hydraulic machinery manufacturer with years of industry experience, FYL combines high-quality materials, precision engineering, and competitive pricing to deliver a product that meets the demands of modern water supply, heating, and industrial systems.

Unlike conventional single-hole air release valves, FYL's double ball design significantly increases exhaust capacity, improves system efficiency, and actively protects pipelines from rupture caused by negative pressure.

How the Double Ball Air Release Valve Works 

Understanding the working principle helps you select the right valve for your application. The FYL double ball air release valve operates automatically based on water and air dynamics inside the pipeline.

1. Initial Air Discharge (Startup)

When the pipeline is first filled with water, the valve stem is turned counterclockwise. The stem rises together with the valve, allowing trapped air to enter the body cavity under water pressure. This air is then expelled through the exhaust nozzle. Once the air is removed, water fills the cavity, causing the stainless steel float to rise due to buoyancy. The float blocks the exhaust nozzle, achieving automatic self-sealing .

2. Normal Operation (Continuous Air Release)

During normal pipeline operation, small amounts of air are continuously released from the water under pressure. This air accumulates at the top of the valve body cavity. As air builds up, the float drops away from its sealing position, opening the exhaust nozzle. The accumulated air is discharged, and the float immediately returns to its original position, resealing the nozzle.

✅ Key point: Under normal operating conditions, the valve remains open, while the float repeatedly opens and closes to continuously release air without manual intervention.

3. Negative Pressure Protection (Safety Function)

If negative pressure occurs inside the pipeline (e.g., during pump shutdown, rapid drainage, or pipe burst), the double ball air release valve automatically opens to quickly inhale air . This prevents pipeline collapse or rupture, protecting your entire system from costly damage.

Why Choose FYL Double Ball Air Release Valve?

1. Significantly Larger Exhaust Volume

Compared to single-hole air release valves, the double ball design provides several times greater exhaust capacity . Even compared to ordinary double-hole valves, FYL's double ball air release valve maintains higher efficiency, reducing air pockets that cause flow resistance, noise, and pipe corrosion.

2. Energy Saving Through Reduced Resistance

Trapped air in pipelines increases friction losses and forces pumps to work harder. By continuously removing air, the FYL double ball air release valve reduces system resistance, lowers pump energy consumption, and helps you achieve long-term energy savings .

3. Automatic Negative Pressure Protection

Many air valves only release air. The FYL double ball air release valve goes further by automatically admitting air when negative pressure is detected. This bidirectional function (release + intake) prevents vacuum conditions that can collapse metal or plastic pipelines.

4. Durable Construction for Long Service Life

• Stainless steel float ball – corrosion-resistant, reliable buoyancy
• RF flange connection – compatible with BS, ASME, JIS, DIN standards
• Wide pressure range – PN10, PN16, PN25
• Temperature range – 0°C to 80°C, suitable for cold and hot water

5. Proven Manufacturing Quality

FYL has spent years developing hydraulic machinery, continuously innovating in product quality, variety, and post-sales service. From precise dimension control to rigorous testing, each double ball air release valve is built to perform reliably over years of operation.

Technical Specifications

Dimensions (mm)

Note: Dimensions conform to standard flange drilling. Custom sizes available upon request.

Typical Applications

The FYL double ball air release valve is widely used in:

• Municipal water supply pipelines – prevents air locks and pressure surges
• Heating and district heating systems – continuously releases dissolved air
• Industrial water treatment plants – protects pumps and filters
• Irrigation systems – maintains steady flow
• Fire protection water networks – ensures system readiness
• Pump discharge lines – prevents vacuum formation during pump stop

Comparison: Double Ball vs. Single Ball Air Release Valve

Installation & Maintenance Tips

To ensure optimal performance:

1. Install at high points in the pipeline where air naturally accumulates.
2. Install vertically with the valve stem facing upward.
3. Use isolation valves upstream for easy maintenance without system shutdown.
4. Periodically check the float and sealing surface for debris or wear (recommended every 6–12 months).
5. Do not insulate over the exhaust nozzle – always keep it free for air discharge.

Why Partner with FYL?

• Complete variety – multiple sizes and pressure ratings available
• High quality + low price – factory-direct manufacturing advantage
• Professional manufacturer – focused on hydraulic machinery for many years
• Continuous innovation – regular improvements based on market feedback
• Pleasant cooperation – attentive service, on-time delivery, clear communication

Send Inquiry

Ready to improve your pipeline efficiency with FYL's double ball air release valve? Contact us with your required:

• Size (DN)
• Pressure rating (PN10/16/25)
• Flange standard (BS, ASME, JIS, DIN)
• Quantity
• Application details

We will respond within 24 hours with a competitive quote and technical support.

Simple Photos

Product Specification

Pressure Rating: PN10/PN16/PN25

Working Medium: Hot and cold water

Working Temperature: 0°C to 80°

Stainless Steel Float Ball

End connection: RF Flange

BS/ASME/JIS/DIN

Dimension(mm)