Accurate dosing pump controls are not just important; they are essential to using your dosing pump efficiently, delivering the output you need for your application and getting the best return on your investment.
Cheaper dosing pumps offer a lower initial purchase price, but they usually don't come with the precision controls you will see on higher-priced pumps, and a solenoid dosing pump may also introduce unwelcome pulsation into its output. For example, in processes where chemical dosing needs to be highly linear, a cheaper solenoid operated pump may create "peaks and troughs" in chemical levels, due to the inherent pulsation effect of this type of pump. While this may be fine for some applications, making the cheapest dosing pumps the most economical option overall, for more intensive and niche uses it's crucial that you put some attention into finding the most suitable dosing pump.
The most basic pump controls will allow you to adjust the speed or the stroke of the pump, or both, but you can get much more consistent output using stepper-motor or electronically controlled motor-driven dosing pumps. On motor driven pumps you can also install optional pulsation dampers and/or pressure retention valves for more consistent output and reduced pressure headloss, allowing the pump to operate in a wider range of operating pressures.
Dosing control is most important of all when the dose rate may be very small, such as is the case when delivering liquid flocculants like PAC; the chemiDOS SMART LD is a stepper motor dosing pump suitable for output of just a few ml per hour. These pumps can combine a very fast suction stroke with a very slow output stroke free from pulsation, so that the overall dose is extremely consistent and reliable. In the long run this accuracy will also deliver savings on chemicals and greatly improve the efficiency of your treatment process. Stepper pump dosing controls commonly include pulse length, pulse frequency and volt free contacts, especially on higher-end pumps, giving you much more flexibility to use the pump for almost any application.
Finally, there are some additional measures you can take to protect your dosing pump and treatment process; installing a pressure relief valve as an extra safety device in the event of an injector blockage, or installing an anti-siphon valve to prevent inadvertent dosing, for example, in the event of a vacuum forming in the process circuit during a shut-down period.
To find out more about the range of dosing and control solutions from Gaffey, or for any technical enquiries, contact us today.