Viessmann Vitomax HS M73 Operating And Service Instructions page 13

Description of selected components in a steam...
Operation
Regular operating checks. Observe country-specific
regulations.
The water column rises quickly to the correct level.
Tab. 9
Pressure monitoring unit
The pressure monitoring unit is directly connected to
the steam boiler via the fitting assembly.
Component
Pressure gauge
rQ
Pressure limiter
rW
Pressure transducer rE
Straight-through shut-off
valve with cap
rR
Tab. 10
to
rQ rR
Function
Operating pressure indica-
tor
If maximum pressure is ex-
ceeded: Protect the steam
boiler against positive pres-
sure
Load-dependent regulation
of the boiler combustion
subject to the operating
pressure
Enables the replacement of
faulty components
(cont.)
Operating information
Close the valve on the water and steam side
Open flushing valve, drain and check the valves for tight-
ness
Open the valve on the water side; check for discharge
noise
Close valve on the water side
Open the valve on the steam side; check for discharge
noise
Leave the valve on the steam side open
Close the flushing valve
Open valve on the water side
If the water column rises slowly, check if there is a block-
age
Operating information
Regular operating check. Observe country-specific reg-
ulations.
Checking with a calibrated test pressure gauge by an
authorised contractor or test body
Safety chain interrupted by opening a contact in the
pressure limiter.
Burner operation is interrupted.
Safety chain is reset by pressing the button on the
■
control panel and the pressure limiter.
Reduce boiler pressure via air vent valve or main
■
steam valve: Approx. 1 bar below the switching point
of the max. pressure limiter
Reset the max. pressure limiter.
■
Burner starts again.
■
Only by authorised contractors
Functions
13