This bronze automatic air vent valve uses a float-operated mechanism to automatically release trapped air from a piping system.
The valve is available in 1/2″, 3/4″ and 1″ sizes with BSP or NPT threaded connections. The bronze body and bonnet are combined with EPDM sealing parts and 304 stainless steel internal components.
It is rated for a non-shock working pressure of 1.6 MPa and a working temperature range of -20°C to 120°C.
How Does an Automatic Air Vent Valve Work?
Air can accumulate at high points or other locations in a water piping system. If it is not removed, trapped air may interfere with normal circulation and create noise or unstable flow conditions.
This valve uses an internal float to control the air outlet automatically.
Trapped air collects inside the upper section of the valve body.
As the liquid level inside the chamber drops, the float moves downward.
The internal mechanism opens the vent and allows accumulated air to escape.
When liquid fills the chamber, the float rises and closes the air outlet.
Important:
An automatic air vent is designed to remove accumulated air automatically. Product selection should still consider system pressure, temperature, medium, connection standard and installation requirements.
Product Specifications
| Parameter | Specification |
|---|---|
| Product Type | Automatic Air Vent Valve |
| Operating Mechanism | Float Operated |
| Body Material | Bronze |
| Bonnet Material | Bronze |
| Connection | Threaded |
| Thread Options | BSP / NPT |
| Size Range | 1/2″, 3/4″, 1″ |
| Working Pressure | 1.6 MPa Non-Shock |
| Shell Test Pressure | 2.4 MPa Hydrostatic |
| Seat Test Pressure | 1.76 MPa Hydrostatic |
| Air Test Pressure | 0.8 MPa / 8 Bar |
| Working Temperature | -20°C to 120°C |
Internal Materials
The catalogue specifies the following materials for the main components:
| Component | Material |
|---|---|
| Body | Bronze |
| Stem | Brass |
| Bonnet | Bronze |
| Air Cap | Brass |
| Gasket | EPDM |
| Stopper | POM |
| Spring | 304 Stainless Steel |
| O-Rings | EPDM |
| Holder | 304 Stainless Steel |
| Float Bar | 304 Stainless Steel |
| Float | Polypropylene (PP) |
Why component materials matter:
An automatic air vent depends on the movement of the float and internal sealing mechanism. The body material alone does not define the complete product — buyers should also pay attention to the float, spring, seals and other internal components.
Dimensions
| Size | L1 (mm) | d | H (mm) | Catalogue Connection Marking |
|---|---|---|---|---|
| 1/2″ | 13.5 | Ø14.5 | 86 | Rp1/2 |
| 3/4″ | 14.5 | Ø14.5 | 88 | Rp3/4 |
| 1″ | 17 | Ø25 | 90 | Rp1 |
Dimension Note:
The dimensional table above follows the catalogue drawing. BSP and NPT versions may require different thread details, so confirm the required connection standard and final dimensions before ordering.
Where Is a Bronze Automatic Air Vent Valve Used?
Float-type automatic air vents are commonly used in water circulation and heating systems where accumulated air needs to be discharged automatically.
Helps release trapped air from suitable water circulation systems.
Can be installed where automatic removal of accumulated air is required.
Suitable for compatible hydronic applications within the product pressure and temperature limits.
Can be evaluated for equipment or piping systems requiring an automatic float-type air release device.
Application Note:
Final product suitability should be confirmed according to the actual medium, system pressure, temperature, installation position and applicable project requirements.
What Should Buyers Check Before Ordering?
For replacement, distribution or OEM projects, confirming several details before quotation can help avoid incorrect specifications.
Confirm whether the project requires 1/2″, 3/4″ or 1″.
Confirm BSP or NPT before production, especially for replacement projects.
Provide the working medium, system pressure and temperature.
Confirm any project-specific pressure, leakage or inspection requirements.
Quality Control Points
For an automatic air vent valve, quality control should cover more than the appearance of the bronze body.
- Thread dimensions and connection compatibility
- Body and bonnet condition
- Correct float and internal component assembly
- EPDM sealing component installation
- Float movement and venting mechanism operation
- Pressure and leakage performance according to the agreed specification
SUNRICH FLOW works with manufacturing partners in Yuhuan, Zhejiang, China and coordinates product specifications, production requirements and quality control for international orders.
Frequently Asked Questions
What does an automatic air vent valve do?
It automatically releases accumulated air from a suitable piping system using an internal float-operated venting mechanism.
What sizes are available?
Standard catalogue sizes are 1/2″, 3/4″ and 1″.
Are BSP and NPT threads available?
Yes. The catalogue lists BSP and NPT threaded connection options. The required thread standard should be confirmed before ordering.
What is the maximum working pressure?
The catalogue specifies a non-shock working pressure of 1.6 MPa for sizes from 1/2″ to 1″.
What sealing material is used?
EPDM is specified for the gasket and O-ring sealing components.
Is the float made of stainless steel?
No. The float is polypropylene (PP). The float bar, holder and spring are specified as 304 stainless steel.
Is this valve suitable for every heating or HVAC system?
Not automatically. Suitability should be checked against the actual medium, system pressure, operating temperature, thread connection and other project requirements.
Need a Bronze Automatic Air Vent Valve?
Send us your required size, BSP or NPT thread standard, quantity and application. For replacement or OEM projects, you can also provide an existing sample, drawing or product specification.