Optional Pump Controls are available for all Williams pumps to allow for automatic control of the injection rate
The APU (Automatic Pumping Unit) Series can control the amount of chemical injected by a Williams pump by controlling the stroke rate from 0-45 strokes per minute based on an input signal. The APU includes a N/C 3-way solenoid valve which takes the place of the Oscillamatic Controller and is rated for hazardous areas as well as being weatherproof.
Williams pumps have the ability to be automated to inject chemical proportional to flow, if a 4-20 mA signal is present, which can save valuable chemical and personnel time adjusting pump stroke rate when the process flow changes.
The APU can be adjusted to match the amount of chemical required for injection based on a maximum stroke rate of 45 or as little as required by the application. For example, if the application requires the pump to operate at 40 spm @ 20mA, representing 100% of flow for example, then the APU would operate the pump at 20 spm @ 12mA for 50% flow signal and 0 spm at 4mA or 0% of flow.