- 87 -
25.2.3 Piping.
The dimension of the forward and return stud on the boiler is 2½”
The expansion is connected to the forward supply; no tabs are permitted on this piping.
The safety pipe for the expansion tank must have a pipe dimension of minimum 1”.
A shunt bypass must be established between forward and return on the boiler, this is to ensure that you
will always get min. 62
o
C hot water back into the boiler and thus avoid cold zone corrosion.
The best way to control the temperature is to mount Thermostat valve or a similar valve on the bypass
pipe, placing the sensor on the return pipe, or a suitable 3-way valve
In this way, hot water will always be provided from the forward supply so that the return has the proper
temperature.
The installation must take place in accordance with to the piping diagram from these instructions appear
in chapter 24.
25.2.4 Anti-freeze measures.
Expansion tanks and safety pipes must be protected everywhere and in their entire lengths against the
formation of ice. To the necessary extent, expansion tanks and water-filled safety pipes must be kept
warm by means of circulating water from the plant, preferably indirect
If the protection against ice formation is made by means of a circulation piping to the safety pipe or the
expansion tanks, that piping must be installed in such a way that it is possible to check the circulation by
feeling the temperature with your hand. A circulation piping may be connected to the safety pipe
immediately underneath the expansion tank, but the distance between the branching and the tank should
only just be as long as needed for placing the fittings.
In case the plant is not operating during wintertime it must be drained, unless it is otherwise protected
against the formation of ice, for example by adding a sufficient amount of anti-freeze solution to the
water.
25.2.5. Check the screw direction of rotation
Before starting up you must make sure that the screw turns in the correct direction = clockwise when
observed from behind the stoker. If the screw turns in the wrong direction, just rotate the phase inverter.