Walchem EH Series, Instruction Manual

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If the chemical is heavier than water, mount the injection valve as close as
possible to vertical coming into the bottom of the pipe. This will keep the
injection nozzle facing up and keep the heavier chemistry from draining into the
pipe and causing adverse reactions within the injection valve and pipe.
In addition to preventing backflow from pressurized lines, the injection valve
acts as a back pressure valve when pumping into atmosphere or low pressure
applications. However, the back pressure by the injection valve can vary and the
valve does NOT act as an anti-siphon valve. If siphoning is a possibility, or if
pumping downhill into open atmosphere (open tank), a Walchem MultiFunction
valve or a separate back pressure/anti-siphon valve must be installed.
Note: Siphoning can also occur at the tip of the injection valve because of the
high flow rate in the main pipe flowing past the small injection nozzle (venturi
effect). In this case, an anti-siphon device must be installed to avoid over
feeding or siphoning of chemistry.
Figure 7 Injection Valve
See Section 5.0 for complete liquid ends parts list and exploded view.
2.6 Electrical
WARNING Risk of electrical shock!
This pump is supplied with a
grounding conductor and grounding-type attachment plug. To reduce the risk of
electrical shock, be certain that it is connected only to a properly grounded,
grounding type receptacle.
Connect the pump power cord to a
GROUNDED outlet supplying proper
voltage. Avoid branch circuits that also supply power to heavy machinery or
other equipment that could generate electrical interference.
Trim back as needed
to fit tee or fitting
Injection/Back Pressure Valve