Yoshitake TA-18ML is a compact float-type air vent valve designed to discharge air automatically from piping systems. Its body and cap are made of stainless steel, offering high resistance to corrosion and durability, while the main internal parts (float) are made of heat-resistant synthetic rubber or plastic. The TA-18ML is widely used for hot water boilers, water heaters, and electrical hot water generators.

Features

• Easy to clean by simply removing the valve seat, even if scale or dirt deposits on the valve disc or valve seat.
• A vinyl hose (hose bore φ6mm) can be easily connected to the TA-18ML to lead discharged water to a safe place.
• In the event of a failure causing water to leak out of the TA-18ML, the leak can be stopped immediately by removing the end cap and tightening the joint cap, ensuring safety.

Specifications

Application	Cold and hot water
Working pressure	0.01-0.3 MPa
Maximum temperature	100℃
Body / Cover Material	Stainless steel
Float Material	Heat-resistant resin / plastic
Disc Material	FKM (fluororubber)
Connection Inlet	JIS R (Rc) thread
Connection Outlet	Hose joint type (Hose joint Φ6)

Note: Some internal parts and the valve seat are made with brass.

Dimensions and Weights

Nominal size	d	H (mm)	Weight (kg)
6A	R(c) 1/8	83	0.12
10A	R(c) 3/8	87	0.13
15A	R(c) 1/2	89	0.13
20A	R(c) 3/4	89	0.13

Exhaust Capacity Chart

Operation and Structure

1. After installation, air exists in the product, and the float is lowered by its own weight. Since the valve disc is kept open by the lever, air is discharged outside by the internal pressure of the system.
2. When air is discharged, hot or cold water flows into the product to make the float come up on buoyancy, and the force that keeps the valve disc open through the lever is lost. Then the valve disc is closed by the spring and pressure.
3. When air bubbles are generated in the system and collect in the product, the inside water level drops, and the float loses buoyancy and opens the valve disc to discharge air.
4. Repeating these processes, air in the system can be continuously removed.

No.	Parts name
1	Body
2	Cover
3	Spring tray
4	Lever
5	Hanger metal
6	Valve disc
7	Guide
8	Valve seat
9	Spring
10	Float
11-13	O Ring
14	Stopper
15	Elbow cap

Piping Example

Using this product in combination with an Air Out (air separator from water) type AO-2 makes the efficiency of air discharge higher.

Precautions for Installation and Use

WARNING

When hot water is used, fluid leakage may cause burns or contamination in the area where the product is installed. Always ensure safety measures are in place.

Installation Tips

• Remove foreign matter and scale from the lines before installation.
• Install the valve vertically in a place where air easily gathers and maintenance can be performed.
• For nominal sizes 6A and 10A, tighten the product by hand (do not use tools). For sizes 15A and 20A, tighten using a proper wrench on the body's hexagonal part. Do not tighten excessively.
• Lead the vinyl hose to the outlet side of the product to a safe drainage place.

If fluid leaks because foreign substances exist on the valve disc and seat, leakage from the elbow cap may happen. As an immediate action, remove the top of the cap and tighten the elbow cap to stop the leakage.

Maintenance and Disassembly

To maintain function and performance, carry out regular inspections.

• Daily Inspection: Check that air is venting properly and that there is no valve seat leakage or external leakage.
• Periodic Inspection (1 time/year): Disassemble and visually check the valve disc, valve seat, and O-ring. Clean if scale or dust is present, and replace damaged parts.
• Recommended Replacement: It is recommended to replace the product every 3 to 5 years.

Disassembly Procedure

DANGER

Completely discharge internal pressure of the product, piping, and equipment, and cool down the product prior to disassembling or maintenance in case of high-temperature fluid.

1. Stop the heat resource (boiler, hot water generator, etc.) and pump.
2. Discharge internal pressure in the piping.
3. Remove the valve seat using a spanner (12mm).
4. Remove the valve seat and clean the scale and dust.

5. After cleaning, fit the O-ring into the ditch on the valve seat and retighten it with a spanner (Torque: Approx. 3N・m).

Note: The O-ring and elbow cap are consumable parts.