• To control the inlet pressure of cold water in the electric or solar water heater
• To prevent the return of hot water contained in the boiler back into the cold water pipe.

• Material: Body and cover made of brass CW617N, EN 12165-99
• Cross-section: 1/2''x3/4''
• Suitable for water and water mixtures (glycol up to 50%) according to DIN 4757/1
• Elastomer diaphragm.
• Factory set discharge pressure and with sealed button.
• Pre-set opening pressure: 8 bar
• Maximum operating temperature: 160 °C

All types of water heaters (solar, electric, wood, etc.) must necessarily have a safety valve or pressure and temperature relief valve as it is otherwise called. The safety valve is usually connected to the cold water inlet of the water heater and has the property of being one-way, i.e., it does not allow the reverse flow of water from the water heater to the cold water supply network. In this case, we say that the valve has a check valve or is a check valve. The safety or relief valve serves two purposes:

• 1. To release water from its nozzle when the pressure and temperature inside the water heater increase excessively. In this way, the pressure and temperature drop back to the limits allowed by the water heater's manufacturing specifications, protecting it from destruction. Here we must say that heating the water also causes its expansion, so the increase in the volume of water and the increase in pressure inside the water heater is normal.
• 2. To function as a check valve, i.e., to prevent water from returning from the water heater to the water supply network. This is useful to isolate the water heater tank from the house's water supply network and prevent the water heater from emptying when we need to turn off the main water switch for various tasks.

In case of valve replacement, we should never use a valve with a higher limit than that specified by the water heater manufacturer.