Rupture of the pressure line
n
With a closed pressure line (e.g. due to a clogged pressure line or by
closing a valve), the pressure that the metering pump generates can
reach several times the permissible pressure of the system or the
metering pump. This could lead to lines bursting resulting in dan‐
gerous consequences with aggressive or toxic feed chemicals.
n
Install a relief valve that limits the pressure of the pump to the max‐
imum permissible operating pressure of the system.
Uncontrolled flow of feed chemical
n
Feed chemical may press through a stopped metering pump if there is
back pressure.
n
Use an injection valve or a vacuum breaker.
Uncontrolled flow of feed chemical
n
Feed chemical may press through the metering pump in an uncon‐
trolled manner in the event of excessive priming pressure on the suc‐
tion side of the metering pump.
n
Do not exceed the maximum permissible priming pressure for the
metering pump or
n
Set up the installation properly for this.
Warning of leaks
n
Leaks can occur at the pump connector depending on the insert used.
n
The pump is supplied with PTFE moulded composite seals with a
flare, which are used for the pump connectors, and which seal the
connectors between grooved pump valves and ProMinent grooved
n
Use an elastomer flat seal in the event that an unflared insert is used
(e.g. third party part) - see Fig. 16.
Warning of backflow
n
Liquid ends, foot valves, back pressure valves, relief valves or spring-
loaded injection valves do not constitute fully leak-tight sealing ele‐
ments.
n
Use a shut-off valve, a solenoid valve or a vacuum breaker for this
purpose.
WARNING!
Product can be dangerously contaminated
Only with "Physiologically safety with regard to wetted
materials” version:
–
The feed chemical will come into contact with seals
that are not physiologically safe if the integral vent
valve or the integral relief valve opens.
–
Do not route feed chemical that escapes from the
integral bleed valve or the integral relief valve back
into the process.
P_SI_0021
Fig. 15: Moulded composite seals with
grooved insert
P_SI_0022
Fig. 16: Elastomer flat seal with a smooth
insert
Integral relief valve
Installation, hydraulic
34
Содержание Sigma / 2 Basic S2Ba
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