baltur GI MIST 1000 DSPGM Instruction Manual page 71

SKP 25,003 E2 VALVE WITH
PRESSURE REGULATOR
IMPLEMENTATION
Servomotor
The hydraulic control system consists of a cylinder full of oil and a
pump with oscillating piston. There is also a solenoid valve between
the aspiration chamber and the pump thrust chamber, for closure.
The piston moves on a sealed joint in a cylinder that at the same
time hydraulically separates the suction chamber from the delivery
chamber. The piston transmits the movement of the stroke directly
to the valve. A red scale that is visible through a transparent slit in
the body of the servo motor indicates valve stroke.
Pressure reducer
The pressure regulator is composed of a membrane (an additional
safety membrane is provided), of a calibrating spring at a specified
value and of an oscillating system for operating a ball valve located
on the by-pass between the intake and the delivery chambers of the
hydraulic system (see also description at "Operation" description).
Regulation field: 0...22 mbar or (after spring replacement) up to
250 mbar. The regulation of the required value can be lead sealed.
Connection to Rp 1/4 gas measurement point. The maximum inlet
pressure depends on the valve diameter.
• The maximum inlet pressure for 3/4" and 1" diameters is 1200 mbar.
• The maximum inlet pressure for 1/1" and 2" diameters is 600 mbar.
• The maximum inlet pressure for 65/4" and 80" diameters is
700 mbar.
Where there is seal control a depression of up to 200 mbar can
be withstood. The servomotor and pressure regulator casings are
made out of die-cast aluminium.
Operation of valve with pressure regulator
Using the valve with pressure regulator, the valve's outlet pressure
acts as a comparative value on a membrane assisted by a spring.
The resistance of the spring can be adjusted and is the "prescribed
value" (set pressure value). The membrane acts by means of an
oscillating system on a by-pass ball valve between the upper and
lower chamber of the servocontrol. If this comparison value is
lower than the required value, the by-pass is closed so that the
servocontrol can open the gas valve. If, on the other hand, the
comparative value is greater than the prescribed value, the by-
pass is to a greater or lesser extent open so that the oil can go
to the lower chamber; the gas valve progressively closes until the
prescribed value and the comparative value of the pressure are the
same. In this position of equilibrium, the by-pass is open so that
its flow rate corresponds with the pump flow rate. In this way, the
regulator acts as a regulator with a proportional action with a very
narrow band. The regulation remains stable due to the fact that
the stroke variation speed is reduced. Removing the screwed plug
gives access to screw "A" which adjusts the pressure.
To increase the pressure tighten the screw;
to reduce the pressure, loosen it.
SKP 15.../ 25... with AGA62.000A000 connector
SKP 25... complete with valve
AGA 25 damper (optional)
Legend:
1 Piston
2 Oscillating pump
3 Oil tank
4 Pressure chamber
5 Shaft
MOD.
- -
AGA22
AGA23
27 / 42
0006080764 _201312
6 Closing spring
7 Operating valve
8 Stroke limit switch (optional)
9 Adjusting spring
10 Ball valve
P GAS colour
(on output) spring
mbar
0...22 METAL
15...120 YELLOW
100...250 RED