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WITT-GASETECHNIK GmbH & Co KG
Salinger Feld 4-8
: +49 (0)2302 89010
www.wittgas.com
Gas Safety- & Control Equipment
D-58454 Witten
Fax: +49 (0)2302 89013
Mixing valve
: Mixing valves are only used in gas mixers for more than two gases.
The percentage portion of the related gas type is set on the mixing
valves. It must be noted that the total of all portions set must always
add up to 100%.
Non-return valve
: The non-return valves prevent the gases from each individual phase
flowing back into the other gases.
Outlet pressure (P
h
)
: The outlet pressure is the mixed gas pressure in the mixed gas re-
ceiver on the outlet of the gas mixer.
Pilot gas
: One of the gases used in the mixing process is defined as the pilot
gas and is used as the medium to be applied to the dome loaded
pressure regulators (via the pilot pressure regulator). If the supply of
the pilot gas is lost, the production of gas mixture is also lost com-
pletely. The pilot gas must therefore always be connected with suffi-
cient gas inlet pressure, even if it is not used in the mixing process
itself.
Pilot pressure regulator : The pressure to be applied to the dome loaded pressure regulator* is
adjusted on the pilot pressure regulator. In the dynamic condition, the
pilot pressure is slightly higher than the constant pressure.
Pressure switch /
Pressure transmitter
: The pressure switches or pressure transmitter monitor the required
gas inlet pressures for the gases supplied. Together with the alarm
module, this then forms the inlet pressure monitoring*. The pressure
switches only monitor the minimum inlet pressure required, and not
the maximum inlet pressure.
Proportional mixing
valve
: A proportional mixing valve is only found on gas mixers for two gases.
Here the percentage portion of the gas named on the adjusting knob
is set. If the portion of a gas is increased, then portion of the other gas
is automatically reduced.
Receiver pressure (P
b
)
: The receiver pressure is the pressure of the mixed gas in the mixed
gas receiver. It fluctuates between the minimum and maximum re-
ceiver pressure that is set on the pressure switch.
Supply gas
: All gases that are mixed including the pilot gas are termed supply
gases.
