ProMinent EXtronic EXBb Operating Instructions Manual page 20

Installation, hydraulic
20
WARNING!
The following measures are beneficial when
working with highly aggressive or hazardous feed
chemicals:
– Install a bleed valve with recirculation in the
storage tank.
– Install a shut-off valve on the discharge or suc‐
tion side.
CAUTION!
Warning of feed chemical spraying around
PTFE seals, which have already been used / com‐
pressed, can no longer reliably seal a hydraulic
connection.
– New, unused PTFE seals must always be
used.
CAUTION!
Suction problems are possible
The valves may no longer close properly with feed
chemicals with a particle size of greater than 0.3
mm.
– Install a suitable filter in the suction line.
CAUTION!
Warning of the discharge line rupturing
With a closed discharge line (e.g. from a clogged
discharge line or by closing a valve), the pressure
that the metering pump generates may reach sev‐
eral times more than the permissible pressure of
the system or the metering pump. This could lead
to lines rupturing resulting in dangerous conse‐
quences with aggressive or hazardous feed chemi‐
cals.
– Install a relief valve that limits the pressure of
the pump to the maximum permissible oper‐
ating pressure of the system.
CAUTION!
Uncontrolled flow of feed chemical
Feed chemical may press through a stopped
metering pump if there is back pressure.
– Use an injection valve or a vacuum breaker.