Design And Principle Of Operation - Samson 46-7 Mounting And Operating Instruction

Design and principle of operation

3 Design and principle of oper-
ation
The combined regulators mainly consist of
the valve (1), closing actuator (6) with two
operating diaphragms (6.1, 6.3) and an ad-
justable restriction (9), on which an addition-
al pressure control actuator (15) with dia-
phragm chamber E is mounted. Its purpose
is to close the restriction (9) when the return
flow pressure is too high to prevent damage
to the consumers.
The regulator is used to limit the differential
pressure and flow rate to the set points ad-
justed at the actuator. The valve closes when
the differential pressure or flow rate increas-
es. The additional pressure actuator closes
the valve when the return flow pressure is too
high.
The medium flows through the valve in the
direction indicated by the arrow. The areas
released by the restriction (9) and the plug
(3) determine the flow rate. The installed
spring (5) determines the differential pres-
sure across the restriction of 0.2 bar.
1 Valve body
2 Seat
3 Guide nipple with plug section
4 Plug stem
5 Valve spring
6 Actuator
6.1 First operating diaphragm
6.2 First actuator stem
6.3 Second operating diaphragm
6.4 Second actuator stem
8 Set point spring (differential pressure)
10
To control the flow rate, the low pressure
downstream of the restriction is transmitted
through a hole in the plug to the top dia-
phragm chamber A. The high pressure of V
is transmitted through the attached control
line to the diaphragm chamber B and C,
which are connected to each other.
To control the differential pressure, the high
pressure of ∆p must be transmitted through
the external control line (13), which is at-
tached on the site of installation, to the bot-
tom diaphragm chamber D. The low pres-
sure of ∆p is equal to the high pressure of
˙
the V and is transmitted over the control line
(11) to the diaphragm chambers B and C,
which are connected to each other.
To safeguard the return flow pipe, the return
flow pressure downstream of the valve is
transmitted over the attached control line
(15.2) to diaphragm chamber E of the addi-
tional pressure control actuator (15) and
compared with the adjusted pressure set
point. If the resulting pressure force is higher
than the set point force adjusted at the set
point adjuster (15.1), the restriction closes,
causing the valve to close as well.
9 Restriction (flow rate)
9.1 Set point screw (flow rate, SW 4)
10 Set point adjuster (differential pressure)
11
Control line (+)
13 External control line (+) Δp
15 Pressure control actuator
15.1 Set point adjuster (pressure)
15.2 Control line (pressure)
15.3 G blanking plug
1 /
8
15.4 Set point spring (pressure)
A to E = Diaphragm chambers
˙
V
EB 3131-1 EN
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