Mode Of Operation - SPX FLOW APV DELTA RG4 Instruction Manual

APV
APV_RG4_UK-6_092017.qxp
fig. 1
installation with
integrated positioner
B
A
fig. 2
installation with
positioner according to NAMUR
F
B
A
3
3.

Mode of Operation

- The table (item 11) shows the parts which have to be replaced
if flow rates are changed. The design of the valves with regard
to the actuating pressure range or flow rate is made by the
manufacturer.
- The connections for the electric and pneumatic supply lines are
located at the valve positioner (E).
D
The pneumatic actuator (D) provides the path and the force to
open or to close the control element. The diaphragm actuator
is suited for longer actuating distances at minimum self-friction.
The valve positioner (C) guarantees the preset coordination
between valve position and control signal. It compares the control
signal (4-20 mA) given by the control device with the stroke of
the control element and defines the pneumatic actuating pressure
as output signal.
C
Depending on the specific requirement, the modulating
E
valve can be operated either with spring opening or with spring
closing function.
MFS - diaphragm actuator, spring closing
The actuator opens by actuating pressure and closes by spring
pressure.
MFH - diaphragm actuator, spring opening
The actuator closes by actuating pressure and opens by
spring pressure.
For the various applications, the diaphragm actuators are supplied
with different diaphragm surfaces and different actuating pressures.
In its standard design, the valve positioner is a electro-pneumatic
transformer. A pneumatic valve positioner (control signal 0.2-1.0
bar) is also available for specific operations.
D
The direction of flows transferred can be
rising (directional equality >>) or falling (directional reverse <>).
The valve positioner can be installed in two different ways:
C
1) valve positioner integrated in the diaphragm actuator;
the feedback of the valve position is effected as mechanical tap
at the valve shaft within the integrated positioner (fig. 1).
2) valve positioner according to NAMUR (fig. 2);
the positioner is installed at the valve yoke by means of a rib.
E The feedback of the valve position is effected via the operating
cam with fastening plate installed at the valve shaft.
Valve position indication can also be effected in the positioner -
either by indication of the valve end position or by an analog
feedback for the whole stroke range (4-20 mA).
UK
Modulating Valve
DELTA RG4 - MFS + MFH
Instruction Manual: UK-rev. 6