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Concrete Doors and Vaults (Pty) Ltd

Ver. 033

Concrete Vents

Swivel Venturi Vent (2)


Three types of vents, one for air flow, and two suitable for lowering the humidity in valve chambers, are discussed here :

2. Swivel-Venturi Vent

3. Enclosed-Venturi Vent

The principle here is that the venturi can rotate horizontally, and a vertical vane aligns it with the wind. Then as the wind passes through the narrow section of the venturi a suction is created that pulls out the moist air from the valve chamber - which is  replaced with drier air from outside. This vent system is suitable for all valve chambers and reservoirs, and may be made from steel or plastic.

Here there are two venturis, at 90 degrees to each other, so that regardless of the direction of the wind at least one will suck air out of the chamber. Furthermore the efficiency of both these venturis are improved by enclosing them in a cylindrical body such that only their two ends are open to the outside. According to the laws of fluid dynamics the air pressure in the lower right venturi is greater than atmospheric pressure on the upwind side and conversely lower than atmospheric on the downwind side - this forces more air through the venturi, making it in effect a super venturi. On the other hand the venturi at the top left experiences a negative pressure at both ends (owing the wind moving faster at these sides, resulting in lower pressure), and hence both ends of the venturi will suck out humid air from the chamber. In these vents the ducts and funnels of the venturis may all be made of thin plastic, and encapsulated in cylindrical body of concrete. This effectively makes this vent virtually immune to theft/vandalism.

Enclosed Venturi Vent (3)


Swivel Venturi Vent for valve chambers and reservoirs Enclosed Venturi Vent for chambers

    Press on the links above for a 1-page PDF

1. Panel-Vent

The Panel Vent consists of a matrix of air passages. Each air passage has internal dimensions of 146mm by 146mm (X and Y axes respectively), and the Z axis dimension is made to be the same as the thickness of the wall. It is evident that more or fewer air passage columns, and/or rows can be used depending on ventilation requirements. The 146mm by 146mm openings are too small for even a child’s head to go through, and are lined with steel plates welded together, which are in effect permanent shutters. The spaces around the air passages are filled with 60 MPa reinforced concrete. The final construction is extremely strong, robust, and vandal resistant.


Panel-Vent (1)

Concrete Panel Vent for the ultimate in air flow

Crime, theft and vandalism is rife.

We protect your sub-stations, pump houses, pump stations, control rooms, valve chambers, sewer plants, boreholes, generators, transformers, control panels, valves and cathodic equipment with concrete doors, vaults, lids and vents.

Protect and secure your structures and equipment from vandalism by criminals and thieves with our extreme, vandal proof, anti-theft products made with chisel proof Y12 rebar reinforcing and 60MPa concrete, offering extreme protection.