baltur GI 450 DSPGN ME Mode D'emploi Pour L'utilisation Et L'entretien page 34

INSTRUCTIONS FOR REGULATING SIEMENS GAS VALVE SKP 25.003 E2 with pressure
regulator
EXECUTION
Servo motor
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 liquid tight 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
travel.
Pressure regulator
The pressure regulator consists of a membrane (there is a safety
E
supplementary membrane), a spring of the prescribed calibre and
an oscillating system that activates a ball valve on the by-pass
N
between the suction chamber and the hydraulic system delivery
(see also the section"). "Working"). Regulation field: 0...22 mbar
G
or (on spring replacement) up to 250 mbar. The set value adjust-
ment can be placed under seal. Rp 1/4 gas pressure take-off.
L
The maximum input pressure depends on the valve diameter.
For diameters of 3/4" and 1" the maximum input pressure is 1200
I
mbar.
For diameters of 1"1/2 and 2" the maximum input pressure is 600
S
mbar:
For diameters DN 65 and DN 80 the maximum input pressure is 700
H
mbar.
Where there is seal control a depression of up to 200 mbar can
be withstood. The body of the servo motor and of the pressure
regulator are made of die-cast aluminium.
Functioning of valve with pressure regulator
Using the valve with pressure regulator, the valve's ou-
tlet pressure acts as a comparative value on a membrane
assisted by a spring. The resistance of the spring can be adju-
sted an constitutes the "prescribed value" (set pressure value).
The membrane acts by means of an oscillating system on a
by-pass ball valve between the upper chamber and the servo-
control. If the comparative value is lower than the prescribed
value, the by-pass is then 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 cham-
ber; the gas valve progressively closes until when the prescribed
value and the comparative value of the pressure are the same.
In this state of balance, the by-pass is open so that its flow capa-
city is equal to that of the pump. In this way the regulator acts as
a proportional regulator over a very narrow band. The adjustment
is nevertheless stable since the speed of travel variations is limi-
ted. Removing the screwed plug gives access to screw "A" which
adjusts the pressure. Tighten to increase the pressure or slacken
to reduce the pressure.
Legend:
1 Piston
2 Oscillating pump
3 Oil tank
4 Pressioner chamber
5 Shaft
6 Closing spring
7 Work valve
8 Limit switch (optional)
9 Adjustment spring
10 Ball valve
16 / 16
0006081361_201002
SKP 15../ 25.. with connecting cable AGA62.000A000
SKP 25... complete with valve
Damping AGA 25 (optional)
type P gas (in delivery)
(mbar)
-- 0... 22
AGA22 15...120
AGA 23 100...250
N° 0002910940
Rev. 28/09/05
Spring
colour
bright
yellov
red