Walchem’s WBL
(single) or WDB (double) 400 Series controllers feature
single or dual conductivity input channels for use in
control of boilers under 250 psi. Automatic blowdown
& chemical feed for one (WBL) or two (WDB) boilers
within 500 feet of each other. 400 Series monitor the
condensate return of boilers and will automatically
divert contaminated condensate. The units offer precise
conductivity monitoring and control to keep boiler water
at the correct conductivity. The WDB dual input is more
cost effective than two single input models. Optional
single or dual isolated 4-20 mA output is available. The
WBL and WDB controllers have the ability to store
conductivity and temperature values, water usage, relay
status, and user settings. A USB memory stick is all
that’s needed to extract the information. Download
logs from the USB stick to a PC at your convenience, or
copy your preferred control settings to another
controller to speed start-up. It couldn’t be
easier!
Unique time proportional control
Walchem offers a unique time proportional control algorithm for timed (intermittent) sampling. This algorithm allows the controller to measure the conductivity of the boiler water sample with the control valve closed (which eliminates flashing problems). After getting an accurate reading of the conductivity, the controller performs a timed blowdown that will vary in its duration, extending the blowdown time as the conductivity moves further from the set point.
Typical dual boiler installation
