
QB2 double-port exhaust valve is a critical device in pipeline systems for expelling gas and reducing pipeline resistance, primarily installed at pipeline high points or dead-end sections, suitable for liquid pipeline systems such as water supply, HVAC, etc.
Core Features
Automatic Exhausting: Dynamically controls the opening and closing of the exhaust port with the rise and fall of the float ball. The float ball descends to expel air when gas accumulates, and seals the exhaust port when the water level rises.
Anti-Back Pressure Protection: Automatically draws in air during negative pressure in the pipeline to prevent bursting.
Applicable Temperature Range: Medium temperature range is 0-80℃ (some models support -5-80℃).
Structural Features
Material: Valve bodies are typically made of cast iron, cast steel, or stainless steel, with the float ball being made of stainless steel to extend service life.
Connection Method: Flanged connection available, with customization for flange sizes.
Operation Method: Clockwise rotation to close the valve, counterclockwise rotation to open.
Application Scenario
Suited for pipe systems with nominal diameters of DN50-300, particularly recommended for pipes with diameters over 350mm.
Commonly used in water supply systems and fire sprinkler systems where gas discharge is required.
Maintenance and care
Regular inspections of the valve body cleanliness and seal condition are required to prevent blockages that could affect exhaust efficiency.


































