& nbsp; < b > unloading valve 3512N - 001 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; (with dryer) 1 - inlet & nbsp; M22X1.5-6H & nbsp; 2 - the port & nbsp; & nbsp; M22X1.5-6H & nbsp; 4 - control export & nbsp; M12 x 1.5-6H & nbsp; 3 - exhaust port < b > use: < / b > the valve can automatically adjust the working pressure of the brake system, prevent airflow overload, the removal of water, oil and other debris, and can supply gas to the tire. applicable models: EQ3094F6D, EQ1092FD, EQ1061, EQ1141G and other air brake models.