SPX APV DELTA SDU4, Operating Manual, Page: 8 / 39

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3. Mode of Operation
Double seal change-over valves DELTA SDU4 have been
developed for the use in the brewing and beverage industries, in
dairy and food applications as well as for the chemical and
pharmaceutical industries.
The field of application of the DELTA SDU4 comprises the safe
shut-off and change-over of line sections. The upper and middle
housing are separated from one another by two seat seals.
A leakage chamber is arranged between the seals; the leakage
chamber being forcible closed by the two leakage valves or opened
to the atmosphere.
Leakage at the seat seals of the upper valve shaft is discharged
via the leakage valves to the atmosphere and indicated.
- Operation by pneumatic actuator with air connection.
The actuator is generally mounted normally closed (NC).
- The inner parts of the actuator are maitenance-free.
- To avoid pressure hammers, the valve is to be closed against the
flow direction of the fluid.
- As standard design a control unit DELTA CU21N with NOT element
is installed on top of the actuator for the pneumatic control of the
valve. The NOT element fulfills the task to increase the closing
forces of the closed valve.
- The yellow luminous diodes in the control unit indicate the position
of the valve shaft.
- Observe service instructions to ensure safe maintenance of
the valve.
3
actuator
position
indicator
Control Unit
Delta CU21N
clamp
leakage
valves
housing
housing
Double Seal Change-Over Valves
Delta SDU 4
Operating Manual Rev. 1
UK