VEF 100 plastic air drain valve

Plastic plate air bleed valves have an easily adjustable center element for flow control. The plate valve is provided with sealing tape for sealing in the mounting ring. Plastic valves can be cleaned with mild solutions of non-aggressive detergents. VEF valves are made of polypropylene, colour white (RAL9003). They resist some diluted chemicals. The highly advantageous aerodynamic shape reduces valve noise and significantly reduces the risk of crosstalk. The mounting frames are made of galvanized sheet metal.

- for air extraction suitable for homes, offices, etc.
- good adjustment parameters
- low noise level
- quick and easy installation
- easy air flow measurement
- low pressure drop
- ambient temperature up to 100 ˚C
- resistance to some chemicals

Installation

The valves are inserted by flat springs into the VLZ wall, which allows the valve to be fixed in the ceiling structure or in the wall. A plate valve is inserted from one side of the brickwork, a flexible flex head is inserted from the other side and the joint is fixed with steel or nylon clamping tape. The wall can also be fixed in a circular pipe.

Measuring and control

The air flow is controlled by rotating the centre disc, which changes the valve opening "a" (mm). Air flow measurement is performed as a pressure differential measurement using a measuring tube. See diagrams for more details. The dependence of the flow rate and pressure drop on the valve opening "a" is expressed by:

q = k √Δpm (l/s),(Pa)