TLV VC2 automatic air vent is designed for water piping systems up to 0.5 MPaG (75 psig). This model vents air at start-up and throughout operation for moderate to hot water up to 90 °C. It may also serve as a vacuum breaker in pressurized systems.

Configuration

No.	Part Name
1	Body
2	Cover
3	Float
4	Valve Seat
5	Cover Gasket
8	Name Plate

Specifications

Specification	Value
Size Inlet / Outlet	15 / 10 mm (1/2 / 3/8 in)
Maximum Operating Pressure	0.5 MPaG (75 psig)
Minimum Operating Pressure	0.05 MPaG (7 psig)
Maximum Operating Temperature	90 °C (194 °F)
Maximum Allowable Pressure*	0.5 MPaG (75 psig)
Maximum Allowable Temperature*	185 °C (365 °F)

WARNING

*Maximum allowable pressure (PMA) and maximum allowable temperature (TMA) are PRESSURE SHELL DESIGN CONDITIONS, NOT OPERATING CONDITIONS.

Proper Installation

• Installation, inspection, maintenance, repairs, disassembly, adjustment and valve opening/closing should be carried out only by trained maintenance personnel.
• Take measures to prevent people from coming into direct contact with product outlets.
• Install for use under conditions in which no freeze-up will occur.
• Install for use under conditions in which no water hammer will occur.

1. Before installation, be sure to remove all protective seals.
2. Before installing the product, blow out the inlet piping to remove any piping scraps, dirt and oil. Close the inlet valve after blowdown.
3. This product must be installed vertically within the limits of inclination, with the inlet at the bottom and the outlet at the top, as shown below (Figure 1).
4. Install the product in a location where air is likely to collect, such as a bend in the piping.
5. Install outlet piping leading to 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 the vacuum formed when the system shuts down.
6. Be sure to install a valve and strainer (40 mesh or finer) at the product inlet.
7. For the inlet connection, use a pipe/fitting, etc. with an inner diameter of at least 16 mm (5/8"), such as a schedule 40 pipe or pipe nipple with a nominal diameter of 15 mm (1/2"). A smaller pipe may prevent water/air displacement.

Inspection and Maintenance

Visual inspections should be carried out periodically to determine whether the automatic air vent is operating properly or has failed. Operational inspections should be performed at least twice per year, or as called for by the air vent operating conditions. Air vent failure may result in damage to piping and equipment, resulting in faulty or low quality product manufacture.

DANGER

NEVER apply direct heat to the float. The float may explode due to increased internal pressure, causing accidents leading to serious injury or property and equipment damage.

• Before attempting to open the air vent, close the inlet valve and wait until the body has cooled completely. Failure to do so may result in burns.
• Be sure to use the proper components and NEVER attempt to modify the product.
• If using a vice when dismantling the air vent, screw a nipple or pipe end into the inlet to prevent deformation of the threaded connection.

Parts Inspection Procedure

Part	Procedure
Gaskets	Check for warping or damage
Valve Seat Surface	Check for scratches or wear
Float	Check for deformation, damage, oil film or liquid inside

Disassembly/Reassembly

Part & No.	Disassembly	Reassembly
Cover 2	Clamp the hexagonal part of the vent body in a vice and use a wrench to loosen the cover	Consult the table of tightening torques, coat threads with anti-seize, and tighten to the proper torque
Cover Gasket 5	Remove gasket and clean sealing surfaces	Replace with a new gasket if damaged
Valve Seat 4	Push valve seat inwards from the outlet side, being careful not to scratch. Remove with a socket wrench, being careful not to scratch the seating surface	Using a finger, push into place from the interior side of the cover. Consult the table of tightening torques, coat threads with anti-seize, and tighten to the proper torque

Tightening Torque and Distance Across Flats

Part & No.	Torque N·m (lbf·ft)	Distance Across Flats mm (in)
Cover 2	100 (73)	24 (15/16)

Troubleshooting

If the expected performance is unachievable after installation of the air vent, check the following points to take appropriate corrective measures.

Problem	Cause	Remedy
No air discharged or discharge is poor (blocked)	Air is not reaching the vent because the liquid in the piping is not being displaced by air	Correct the inlet piping (Inner diameter should be at least 16 mm [5/8"])
	Valve seat is clogged	Clean valve seat
	Inlet or outlet piping is clogged	Clean piping
	The operating pressure exceeds the maximum specified pressure for this product	Replace the air vent with a model that has a suitable operating pressure rating
Water leaks when valve is closed*	Build-up on the surface of the valve seat or the valve seat is damaged.	Clean or replace with new valve seat
	Float is dirty, coated with a film, or is deformed	Clean or replace with new float
	Improper installation	Correct the installation
Valve does not close, and liquid spurts out	Water is inside the float	Replace with new float
	Specific gravity of the liquid is not suitable for this product (This product is for water systems)	Select a product with suitable specifications for the operating conditions (consult TLV)

*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 vent closes.