Core Definition and Functions
Basic Attributes: A specialized fastener featuring an integrated, hollow, through-bore structure that combines pipe connection/securing with air venting and pressure relief capabilities.
Core Functions: Expels gases released during pipeline filling or operation to prevent airlocks, pump cavitation, and water hammer effects; also balances internal and external air pressure during drainage to prevent pipe collapse.
Common Applications: Hydraulic circuits, heating water circulation systems, automotive cooling systems, mold cavities, vacuum automation equipment, etc.
Key Working Principles
Manual Venting Type: Loosening the bolt allows accumulated gas to escape through the central through-hole; tightening it restores the seal. Commonly used in automotive cooling systems and small-scale heating pipelines.
Automatic Venting Type: Features an internal float-and-lever mechanism. When air enters the valve chamber, the float drops to open the vent; once gas is expelled, the rising water level pushes the sealing element to close the vent, preventing fluid leakage.
Microporous Venting Type: Utilizes fine micropores (0.03mm–0.035mm) to expel unwanted gases, preventing defects such as scorching or air bubbles during the molding process.
Common Mainstream Types
Stainless Steel Air Bleed Bolts: Highly corrosion-resistant; widely used in residential heating and water circulation systems operating in humid conditions, as they are resistant to rusting and seizing.
Hydraulic Motor Air Bleed Bolts: Specifically designed for marine hydraulic systems to meet the venting requirements of high-pressure hydraulic lines.
Vent/Vacuum Hollow Bolts: Customizable with full through-bore or stepped-bore structures, supporting multiple functions such as venting, vacuuming, and fluid (oil/water) flow.
Vehicle-Specific Air Bleed Bolts: Made from PP/glass fiber composite materials; compatible with cooling systems in vehicles like BMWs; resistant to ethylene glycol corrosion and safe for use with aluminum interfaces.
