baltur GI Series Instruction 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
E
The pressure regulator consists of a membrane (there is a safety
supplementary membrane), a spring of the prescribed calibre and
N
an oscillating system that activates a ball valve on the by-pass
between the suction chamber and the hydraulic system delivery
G
(see also the section"). "Working"). Regulation field: 0...22 mbar
L
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.
I
The maximum input pressure depends on the valve diameter.
For diameters of 3/4" and 1" the maximum input pressure is 1200
S
mbar.
For diameters of 1"1/2 and 2" the maximum input pressure is 600
H
mbar:
For diameters DN 65 and DN 80 the maximum input pressure is 700
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
0006081361_200805
SKP 15../ 25.. with connecting cable AGA62.000A000
Damping AGA 25 (optional)
type P gas (in delivery)
--
AGA22
AGA 23
16 / 16
N° 0002910940
Rev. 28/09/05
SKP 25... complete with valve
Spring
(mbar) colour
0... 22 bright
15...120 yellov
100...250 red