Water Monitoring System
User Manual
Page
36
of 82
Ver. 1.1 – Revision March 2022
6.3 Adjustment of needle valve
The white needle valve located above the de-bubbler controls the ratio of
water/air mix flowing from the top of the de-bubbler and the flow of bubble-
free water that flows from the bottom of the de-bubbler to the sensors.
The valve must never be fully closed, otherwise it will stop the de-bubbler
from functioning. Turning the handle clockwise will increase the flow to the
sensors.
The valve is typically set to 30% open, which corresponds to approximately
2.5 turns made counterclockwise from the fully closed position. If the valve
is closed more, there is a greater risk of it becoming blocked with sediments.
This should be avoided. If the measured flow [l/minute] is unaffected by
valve adjustments, then the valve is probably blocked or broken. If this is the
case, either clean the valve or replace the valve.
6.4 Adjustment of flow
The flow of water through the WMS is determined by the system inlet
pressure, cleanliness of the strainers, the needle valve setting, the
backpressure at the outlet flange, and the pipework’s dimensions and
length. For systems equipped with a pressure reduction valve, the setpoint
pressure of the pressure reduction valve will also affect the flow of water
through the WMS.
In general, water flow through the WMS should be kept as low as possible
so that the strainers will be required to be cleaned less regularly. However,
the water flow must also be high enough to avoid tripping the low flow
warning too often. This means that the optimum flow setting will vary with
each installation and thus the user must make fine adjustments based on
experience with the system.
Recommendation for systems with pump
Choosing the correct pump type and pressure/flow characteristics are
essential for optimal operating conditions. Carefully study section 2.2 and
5.1.3 to choose the correct pump.
6.5 pH/temperature electrode
The pH/temperature sensor uses an electrode which is stored inside the
system in a separate container to maximize electrode lifetime. The electrode
is packed in a sealed bag and delivered with a safety cap on to ensure the
electrode is kept moist.
The electrode will be damaged if it dries out. The cap must be removed
prior to start-up of the system. The pH/temperature sensor is also fitted with
a plug to prevent moisture from entering the electrical connection. The plug
must be removed, and the electrode fitted prior to start-up.
