Two-way thermal release valve SYR 5067 - 3/4 with pressure reducing valve

Field of application: The thermal safety combination type 5067 prevents excess temperatures in solid fuel fired boilers. This protective device can be attached to solid fuel boilers without integrated hot water storage vessels.

Installation and function

Connect the inlet of the thermal safety combination to the water supply. The outlet of the inlet valve leads to the heating return line. Connect the radiator supply line to the outlet valve of the thermal safety combination. The outlet of the inlet valve leads through the integrated tundish to the drain.

Install the temperature probe at the hottest spot, preferably in the upper part of the boiler. Only use the immersion sleeve enclosed in the delivery to ensure correct temperature measurements. Set the pressure reducing valve to a pressure below the highest admissible operating pressure of the heating system in order to prevent a response of the diaphragm pressure relief valve, which is imperatively required for the protection of the boiler against excess pressure.

When the temperature exceeds the set response temperature, the following operational sequence is started: The seat of the inlet valve opens at a temperature of about 90°C in order to keep the pressure stable in the heating system. The outlet valve opens at 97°C. When the outlet valve is opened, hot water is drained from the heating system and cold water can enter from the supply pipe, which will cool down the boiler. When the boiler temperature has dropped to 94°C, the outlet valve closes. The pressure reducing valve ensures with the inlet valve still open that the heating system operates at correct service pressure. When the temperature has reached 88°C, the inlet valve closes.

The thermal safety combination includes the following components (in direction of flow):

check valve
pressure reducing valve
temperature activated inlet valve
temperature activated outlet valve
temperature probe

Usage for boilers with nominal power up to 100 kW

Pressure regulator pressure: 1,2 bar (Factory setting)
Maximum input water pressure: 16 bar
Minimum required water inlet pressure: 2,3 bar
Maximum operating temperature: 135°C
Mass 1,5kg

	Opening temperature	Closing temperature
Filling valve	90°C +0/-2°C	88°C +0/-2°C
Ejection valve	97°C +0/-2°C	94°C +0/-2°C

Water flow through thermal protection 5067 at specified temperature and setpoint of pressure reducer, with assumed cold water inlet pressure 8 bar:

Pressure regulator setting [bar]	Flow Q [m3/h] at 100°C	Flow Q [m3/h] at 110°C
1,5	0,58	1,35
2,5	0,73	1,95
3,0	0,82	2,17
5,0	1,10	2,90

Data sheet

Weight [ kg ]	1.50
Thread type	³⁄₄''
Installation	Vertical, Internal
Max. working temperature [ °C ]	135
Opening temperature [ °C ]	97
Flow Rate [ l/h ]	2900