The A.R.I. D-040 is a plastic combination air valve suitable for discharging and admitting both small and large quantities of air. The air valve combines a large opening (kinetic function) with a small opening (automatic function). This combination ensures a self-cleaning effect (thus less clogging) and prevents premature closing.
The DG-10 is the agricultural version of the D-040. It is designed for a lower pressure and higher capacities. The DT-040 is a combination air valve with integral valve for smaller capacities.
In situations where both a large quantity of air has to be discharged/admitted in a short time or an automatic function is also necessary.