Yoshitake AL-68-97 is mainly installed in the plumbing systems of heat exchangers, which are used for hot water boilers or electric water heaters operating at a pressure of 100 kPa or less. This valve automatically discharges water to protect the machinery when pipeline pressure abnormally increases. Its closed structure prevents fluid flow to the outside even if the diaphragm breaks.

Features

• A large diaphragm at the pressure receiving section enables it to blow out a large capacity at first operation. It also makes the blow down pressure small and operate sharply.
• Breather structure prevents the machinery and pipes from negative pressure problems.
• Manual lever enables checking the operation and water level. It can also quickly discharge water inside the system.
• The diaphragm is made of heat and water-resistant synthetic rubber.

Specifications

Application	Cold and hot water
Commence-to-blow pressure	97 kPa
Reseating pressure	92 kPa or more
Breathing pressure	-12 kPa or less
Max. temperature	100°C
Body	Bronze
Diaphragm	Synthetic rubber (with fabric)
Connection	JIS R 3/4 x JIS Rc 1/2 screwed

Available with commence-to-blow pressure 190 kPa for AL-68-190.

Flow Characteristic Chart

Vacuum Characteristic Chart

INFO

The value is not a standard value but an observed value.

Maximum Pressure of Water Pressure Reducing Valve, Relief Valve and Hot Water Heat Exchanger

Water pressure reducing valve (kPa)	Relief valve for hot water maker (kPa)	Max. pressure of hot water heat exchanger (kPa)
80	95, 97	100
85	97	100
120	190	200
150	190	200
170	190	200

WARNING

Using the bold font valves to simple boiler (100 kPa) is illegal.

Piping Example

Precautions for Installation and Operation

1. Please be sure to remove foreign substances and scales from inside of the piping before connecting the product to the piping.
2. Install pipe at the relief valve outlet side and conduct to a drain ditch. Also install the relief valve so as to check the operation visually.
3. Relief valve will be opened by lifting the lever horizontally. Please check the operation 1-2 times a month.
4. Styrofoam package can be used as heat insulating material to prevent freezing.