Yoshitake TA-3C air vent valve is designed for building equipment, industrial equipment, and building complexes. It features a synthetic rubber valve seat for leak-free operation and a Nylon 11 coating on both the inside and outside of the body for enhanced durability.

Features

• No leakage from the valve due to synthetic rubber used for valve seat.
• Nylon 11 is coated inside and outside of the body.

Specifications

Model	TA-3C	TA-3C-N
Application	Cold and hot water, Oil (Specific gravity 0.8 or more)	Cold and hot water
Working pressure	0.01-1.0 MPa	0.01-1.0 MPa
Maximum temperature	60°C (Intermittent usage 90°C for TA-3C)	60°C
Body, Cover	Ductile cast iron (FCD450)	Ductile cast iron (FCD450)
Valve	Brass	Brass
Valve seat	Brass (equipped with NBR disc)	Brass (equipped with FKM disc)
Float	Stainless steel	Stainless steel
Connection	JIS Rc screwed	JIS Rc screwed

INFO

• Maximum temperature 90°C when intermittent usage (TA-3C).
• Insulate the product when the temperature difference with the atmosphere is 40°C or more.
• Coating: Use Nylon 11 (white) for inside and outside of the body and cover.
• TA-3C-N is compliant with waterworks law capacity standard.

Dimensions and Weights

Nominal size	d	d1	H (mm)	C (mm)	Weight (kg)
15A	Rc 1/2	Rc 3/8	139	114	2.85
20A	Rc 3/4	Rc 3/8	139	114	2.85
25A	Rc 1	Rc 3/8	143	114	3.00
32A	Rc 1-1/4	Rc 3/8	143	114	3.00

Discharge Capacity

Exhaust Capacity Chart (TA-3, 3C, 6):

Features of Nylon 11 (used for TA-3C, TA-3C-N)

• Water absorption is low, and wear resistance is excellent.
• Seawater resistance and critical atmosphere resistance are very good.
• Outdoor weather resistance is outstanding.
• Heat resistance and hot water resistance are fine.
• Nylon 11 is applicable to food-related equipment because it is nontoxic (accepted by FDA).
• Chemical resistance is great.
• Electric insulation and sound damping performance are superb.

Characteristics comparison of powder coating film

Characteristics \ Coating	Nylon 11	Epoxy	Acrylic	Polyester	Polyethylene	PVC
Specific gravity	1.04-1.1	1.3-1.6	1.3-1.6	1.3-1.6	1.0	1.3
Hardness (Pencil)	F	2H	H	H	HB	B
Max working temp (°C)	100-130	100-150	100-120	100-170	70-80	70-80
Wear resistance	◎	○	△	△	△	△
Impact resistance	◎	○	△	△	△	◎
Adhesion	◎	○	○	○	△	△
Low-temp characteristics	◎ -50°C	○	○	○	○	×
Weather resistance	○	×	◎	○	△	○
Alkali resistance	◎	○	○	△	○	○
Acid resistance	△	○	○	○	◎	◎
Solvent resistance	◎	◎	×	◎	△	×
Salt water resistance	◎	○	△	○	○	○
Symbols: ◎ Excellent, ○ Good, △ Care required, × Unacceptable

Operation

1. When installation, the float is in the lowered position and the valve seat is in opened position.
2. When water flows into the valve, pipe air is exhausted out of the valve seat being pushed by water.
3. The float is pushed up floating by water flowed into, and the valve connected with the float is closed.
4. With air coming into, the float is lowered immediately, and at the same time the valve is lowered, and therefore the air is exhausted out of the valve seat.

Maintenance and Installation Precautions

Caution before usage

• For brass parts, corrosion is generated or accelerated by water quality, and leads to malfunction.
• Impact by rapid pressure change, such as water hammer, breaks the product.
• Clean the product thoroughly so as not to leave dirt, foreign matter, oils, solvents, chemicals inside the pipe before installing.
• Install the product to the place where air is easy to accumulate, upright within 5 degree angle to the vertical.
• For installation on piping, please tighten the hexagonal part of the main body with a wrench. Do not tighten more than necessary.

• Remove foreign matter and scales from the lines before connecting the product, and install the valve vertically at the place where air easily accumulates.
• Install a stop valve (cock or gate valve) at air vent valve inlet in order to do maintenance and inspection. Do not use globe valve.
• Leakage may occur by foreign matter and scales inside the pipe. Please install pipe to the exhaust hole as shown in the diagram, and make the outlet end prevent from back-flow to the drain.

Warning during operation

• In case of high temperature fluid, do not touch the product directly with bare hands. There is a danger of burning.
• When flowing the fluid, slowly open the fluid supply valve so that water hammer does not occur.

Troubleshooting

Trouble	Causes	Remedy
Air cannot be exhausted	1. Stop valve at inlet side is closed. 2. Piping pressure is above the optimum level.	1. Fully open the stop valve. 2. Reduce the piping pressure, or replace the valve.
Water is blown off	1. Valve and valve seat are bitten by foreign substance. 2. Valve and float are damaged. 3. Valve seat is damaged.	1. Disassemble and clean the valve and valve seat. 2. Replace the complete float. 3. Replace the product.

Disassembly and Assembly

Precautions during disassembly

• Conduct disassembly and inspection by skilled professional person or manufacturer.
• Be sure to discharge all internal pressure before disassembly and inspection of the valve. In case of high temperature application, cool down the valve before disassembly.

Disassembly Procedure

1. Remove the cover clamping bolt (M10).
2. Remove the O ring (G-100).
3. Remove the pin for fixing the float, and remove the complete float.

Caution for Assembly

1. Confirm that there are no foreign substances inside the main body and each part.
2. Check that there are no scratches on the valve body, valve seat and O ring.
3. Apply silicone grease to O ring.

Exploded Drawing and Parts List

No.	Name of Parts	Material
1	Cover	Ductile Cast Iron (FCD450)
2	Hanger	Stainless Steel
3	Valve Guide	Brass
4	O Ring	NBR
5	O Ring	NBR
6	Valve Seat	Brass & NBR
7	Valve	Brass
8/9	Float	Stainless Steel
10	Arm	Stainless Steel
11	Pin	Stainless Steel
12	Pin	Stainless Steel
13	Machine Screw	Stainless Steel
14	Body	Ductile Cast Iron (FCD450)
15	O Ring	NBR