Automatic Air Reservoir Drain Valve

Xiamen Jiedeng JK99-520201 is a purely pneumatic automatic air reservoir drain valve that requires no power supply. It operates within a pressure range of 0.03–1.20 MPa and automatically drains water at a differential pressure of 0.02±0.005 MPa, with each drainage cycle removing 0.12–19 ml of liquid while consuming only 0.02±0.003 L of air. With an integrated design, the total height is just 42.5 mm. It withstands wide temperature ranges from -40°C to 120°C, resists flying debris, salt spray, and low temperatures, and features no electrical components—eliminating circuit failures and eliminate the need for periodic adjustments. It is compatible with various types of passenger and engineering vehicle air reservoirs.

Compressor Drain Valve

① It has no electronic components and does not require the power connection. This can prevent problems such as circuit faults, low-temperature coil burning, and unstable voltage leading to failure. The structure is simple, and the failure rate is relatively low.

② It is installed internally, with only the drainage outlet exposed. It can prevent flying debris impact, salt fog corrosion, and freezing cracking. It is more suitable for harsh working conditions.

③ It is triggered by the pressure difference. No timing parameters need to be set. The drainage is more timely and no compressed air is wasted.

Automatic Air Tank Drain Valve

Comparison of advantages between built-in automatic air tank drain valve and external drain valve

The built-in type is installed inside the air tank, minimizing interference from the external environment: preventing damage to the valve body from small stones during driving, avoiding cracking of the exposed parts due to low temperatures in winter, reducing corrosion and rust caused by salt fog on coastal/salt-sprayed road sections, and being small in size and not occupying additional space on the chassis, making it particularly suitable for the compact installation scenarios of low-floor bus chassis.

Core technical parameters of the automatic air drain valve

FAQ

Q: How much pressure can this water heater withstand? Can it be used for all commercial vehicle air tanks?

A: The working pressure range is 0.03 to 1.20 MPa. It fully covers the pressure ranges of conventional braking systems for commercial vehicles, buses, and construction machinery (the normal working pressure of vehicles is 0.6 to 1.0 MPa). It can be directly replaced with the existing air tank drain plug for installation and is compatible with the majority of vehicle models.

Q: How sensitive is the automatic water drain valve? Can it drain the accumulated water completely in time?

A: The trigger pressure difference accuracy is 0.02 ± 0.005 MPa. As long as there is a slight fluctuation in the system pressure, it will automatically trigger the drainage. The single drainage volume is 0.12 to 19 ml. It can promptly drain the condensate water at the bottom of the storage cylinder, avoiding corrosion of the pipeline due to water accumulation and ice blockage of the braking pipeline in winter. The sensitivity is much higher than that of the traditional float-type drainage valve. There will be no problem of the float getting stuck and not draining water.

Q: Without connecting to an electricity source, how is the auto drain valve driven to operate?

A: It is driven entirely by the pressure difference in the system. The entire process does not require electricity. The working logic is divided into 4 steps for automatic circulation:

1. Pressure balance stage: The sealing spring pushes the valve core sealing pad to seal the valve tightly, and the pressure inside the valve is balanced with the pressure of the air storage cylinder system, maintaining a seal and preventing water from draining;

2. Pressure storage stage: When the system is pressurized, the condensed water carried by the compressed air passes through the filter screen and is stored in the negative pressure air bag. The valve core remains sealed;

3. Pressure difference drainage stage: When the system pressure drops by more than 0.02 MPa (for example, after using the brake air), the pressure inside the valve is greater than the system pressure. The valve core automatically moves up to open the seal, and the accumulated water in the air bag is automatically discharged through the drainage port along with a small amount of gas;

4. Automatic reset stage: After the water is drained, the pressure inside the valve is released, and it re-balances with the pressure of the air storage cylinder. The valve core is automatically returned to its original position by the spring and seals, waiting for the next trigger.