B. Then close the secondary door on the positive pressure side and the secondary door on the negative pressure side.
Differential Pressure Switches for the Auto Backflush Filter
(Adjustable D-P Switch, GE-511 series Mechanical DP Switch, made by A.YITE TECH)
Contact: Mr. Chou
Phone: 13166369204 (wechat)
Tel: 400-852-8332
Email: shanghai@ayite.net
Add: 17 &22, No.2928, Chuan Zhou Highway, Shanghai, 201319, China