TLV VS3 series automatic air vents (clean air vents) are designed to automatically discharge and release air trapped in water-carrying pipes during water transport. It also automatically discharges the air that was entrained in the water during operation and has subsequently been separated and collected in specific locations in the piping.

These float-type mechanical valves are recommended for venting air in purified water and other liquid systems such as in the pharmaceutical, biotechnology, and cosmetics industries.

Features

1. Precision-ground float, three-point seating and valve seat with rubber contact ensure superior sealing.
2. All stainless steel construction provides outstanding corrosion resistance.
3. Only one moving part, the free float, prevents concentrated wear and provides long service life.
4. Internal buff-polishing with an additional interior and exterior electro-polish option to 0.4 μm Ra for improved resistance to bacterial growth.
5. Maintainable design lowers cleaning costs.
6. Dual function as air vent and vacuum breaker.

Operation

1. When water starts to flow through the piping, air trapped within the piping is pushed along by the water pressure and enters the air vent. At first, because the float is positioned in the lower part of the air vent, the valve is fully open and the air passes through the valve seat and is discharged rapidly through the vent.

2. When the air has been discharged and water begins to enter the air vent, the float starts to rise due to buoyancy. This pushes it upwards against the valve opening, thus closing the air vent. If there is a rapid rise in water level (caused by rapidly opening a shut-off valve, etc.), a small amount of water may leak with discharged air immediately before the air vent closes.

3. When more air is trapped in the air vent due to the inflow of water having closed the valve, the water level in the air vent is forced down and consequently the level of the float falls, opening the valve. Air can now again escape through the air vent, and as it does so the level of the water rises, pushing the float upwards again to close the valve. In this way the VS3 series automatically adjusting air vents constantly respond to the flow of air.

4. When draining the piping, the air vent automatically opens to introduce air and remove water more easily (preventing a vacuum from forming in the piping).

Specifications

WARNING

DO NOT use for toxic, flammable or otherwise hazardous fluids. Use only for water and/or air.

Model	VS3-E	VS3-P	VS3-EP
Connection	Clamp End	Clamp End	Clamp End
Size	DN 15, 20 (ISO) 3/4" (ASME-BPE)	DN 15, 20 (ISO) 3/4" (ASME-BPE)	DN 15, 20 (ISO) 3/4" (ASME-BPE)
Maximum Operating Pressure (barg) PMO	6	6	6
Maximum Differential Pressure (bar) ΔPMX	6	6	6
Maximum Operating Temperature (°C) TMO	150	150	150
Clamp type	3-piece (buff-polished)	3-piece (buff-polished)	3-piece (buff-polished)
Finishing Internal	25 μm Ra electro-polished	0.8 μm Ra buff-polished	Buff-polished then 0.4 μm Ra electro-polished
Finishing External	25 μm Ra electro-polished	0.8 μm Ra buff-polished	Buff-polished then 0.4 μm Ra electro-polished
Applicable Fluid	Water, Other Liquids (Specific gravity must be at least 0.8)	Water, Other Liquids (Specific gravity must be at least 0.8)	Water, Other Liquids (Specific gravity must be at least 0.8)

Pressure Shell Design Conditions: Maximum Allowable Pressure (PMA): 10 barg. Maximum Allowable Temperature (TMA): 185 °C.

Configuration

No.	Description	Material
1	Body	Cast Stainless Steel A351 Gr.CF3M
2	Cover	Cast Stainless Steel A351 Gr.CF3M
3	Float	Stainless Steel SUS316L
4	Body Clamp	Cast Stainless Steel A351 Gr.CF8
5	Cover Gasket	High-performance Fluorine Resin
6	Valve Seat	Silicone Rubber

Installation

WARNING

Install properly and DO NOT use this product outside the recommended operating pressure, temperature and other specification ranges.

1. As this product is for the discharge of air from water-carrying pipes, it must not be used for the discharge of air from steam spaces.
2. Before installation, be sure to remove all protective seals.
3. Before installing the product, open the inlet valve and blow out the inlet piping to remove any piping scraps, dirt and oil. Close the inlet valve after blowdown.
4. This product must be installed vertically, with the inlet at the bottom and the outlet at the top, and should be inclined no more than 5° horizontally and front-to-back.
5. Install the product in a location where air is likely to collect such as a bend in the piping.
6. Install the product so that the outlet pipe reaches a drainage vessel or ditch. Make sure the end of the pipe is above the waterline, so that dirt and water can not be sucked up by vacuum when the system shuts down.
7. For the inlet connection, use a pipe/fitting, etc. with an inner diameter of at least 16 mm (5/8 in).

Make sure the product is installed with the raised TLV lettering on the body horizontal.

Dimensions

VS3-P Clamp End (ISO 2852 Clamp / ISO 2037 Tube or ASME-BPE Tri-Clamp compatible)

DN	L (mm)	W (mm)	B (mm)	φD (mm)	φd (mm)	Weight (kg)
15	105	105	125	34	15.2	1.4
20 (3/4")	105	105	125	34 (25)	19.3 (15.75)	1.4 (1.3)

Discharge Capacity

• 1 bar = 0.1 MPa
• Differential pressure is the difference between the inlet and outlet pressure of the air vent.
• Capacities are equivalent capacities of air at 20 °C under atmospheric pressure.
• Air vents used under conditions which exceed maximum differential pressure will fail closed.