Reflex Servimat M Mode D'emploi Original page 31

4.4 Function
1 Secondary tank (optional)
2 Primary tank
3 Vacuum spray pipe
WC Make-up pipe
DC Degassing line
• Gas-rich water from the system
• Degassed water to the system
EC Expansion pipe
• Pipe to the expansion vessel
• Pipe from the expansion vessel
The device is a pressure maintaining station for heating and cooling water
systems. It is used for maintaining pressure, making-up and degassing the water in
heating and cooling systems. The device comprises a control unit consisting of a
controller with hydraulic system, vacuum spray pipe and at least one expansion
vessel.
Expansion vessel:
One primary tank and multiple optional secondary tanks may be connected. A
membrane separates the tanks into an air and a water space, preventing the
penetration of atmospheric oxygen into the expansion water. The "VE" pressure
compensation elbow connects the air space with the atmosphere. The primary
tank is hydraulically flexibly connected to the control unit. The function of the "LIS"
level measuring using a pressure pick-up is thus ensured.
Control unit:
The control unit comprises a control module and a hydraulic module.
• Control module
Comprising the Control Touch controller and the power connection unit. All
pressure maintenance, degassing and make-up processes within the
hydraulic module are monitored and controlled by the Control Touch
controller.
• Hydraulic module
The hydraulic module comprises the pump "PU", the overflow valve
"PV/RKH1" and the make-up valve "WV/MKH1".
The "PIS" pressure sensor records the pressure and the "LIS" pressure pick-up
registers the level; both values are indicated in the Control Touch display.
Interfaces enable the use of additional Control Touch functions  6.4.3 "RS-485
interface",  39.
The device fulfils three functions:
Maintain pressure:
• The pressure in the facility system rises when the water is heated. When the
pressure set at the controller is exceeded, the "PV/RKH1" pressure relief
valve opens and drains water from the system into the primary tank, using
the "EC" expansion pipe. The pressure within the system drops. The
pressure in the facility system drops when the water cools. When the
pressure drops below the set value, the "PU" pump is activated and uses the
"EC" expansion pipe to transport water from the primary tank back into the
system. The pressure in the facility system rises. The controller ensures that
the pressure is maintained, further supported by the stabilisation provided by
the "MAG" pressure expansion vessel.
Degassing:
Two "EC" expansion pipes are required to degas the system water. One pipe is
intended for gas-rich water from the system, while one return pipe returns the
degassed water to the system. During the degassing action, the "PU" pump
and the "PV/RKH1" pressure relief valve are in operation. The pump creates
a vacuum in the spray pipe. • Gas-rich water is conveyed via the degassing
line connection from the facility system to the vacuum spray pipe and
degassed. Details  0 "Sequence of a degassing cycle in the vacuum spray
pipe",  31. This process can be applied in two different variants (continuous
and interval degassing).
Make-up with water for the facility system.
• When the water level in the primary tank falls below the minimum, the
"WV/MKH1" make-up valve opens and make-up into the tank continues until
the set level is again reached. During the make-up process, the number of
requests, the time and the make-up time within a cycle are monitored. Using
a FQIRA+ contact water meter, the system monitors each individual make-up
quantity and the overall make-up quantity.
The Servimat provides the following safety features:
• Optimisation of all pressure maintenance, degassing and make-up
sequences.
• No direct intake of air thanks to a regulation of the pressure
maintenance with automatic make-up.
• No circulation issues caused by free bubbles in the circuit water.
• Reduced corrosion damage due to oxygen removal from fill and make-
up water.
Sequence of a degassing cycle in the vacuum spray pipe
1 Create vacuum in the spray pipe
2 Injection
The degassing operation uses timer-controlled cycles. A cycle comprises the
following phases:
1. Create vacuum in the spray pipe.
The pump starts and conveys water from the vacuum spray pipe. The pump
transports more water from the spray pipe than can be transported via the
connection lines of the water make-up. A vacuum is created.
2. Injection
Opening of the "PV" overflow valves in the "DC" degassing line routes gas-
rich water into the spray pipe. It is atomised by nozzles in the spray pipe. The
atomised water is degassed in the vacuum of the vacuum spray pipe
because of the large surface area resulting from the atomisation. The
degassed water is returned to the facility system via the vacuum pump. The
pressure relief valve means that the pump is set to a constant working
pressure. The working pressure depends on the respective facility system.
3. Discharge
The pump shuts down. The pressure in the facility system causes more
water to be injected into the vacuum spray pipe and degassed. The water
level in the vacuum spray pipe rises. The gases released in the vacuum
spray pipe are released into the ambient atmosphere via the degassing
valves.
4. Idling time
When the gas has been discharged, the device will remain idling until the
next cycle is started.
Degassing programmes
The device controller regulates the degassing process. The controller monitors the
operating states and outputs them to the display.
The controller provides 2 different degassing programmes for selection and
adjustment:
• Continuous degassing
For continued degassing over several hours or days in a sequence of
degassing cycles without idling periods. This degassing programme must be
selected after commissioning and repairs.
• Interval degassing
This comprises a limited number of degassing cycles. There is an idling time
between the intervals. This degassing programme must be selected for
continuous operation.
Servimat M/L — 25.07.2024
Description of the device
3 Discharge
4 Idling time
English — 31