It depends on the operating conditions. In general, a visual inspection can be done monthly, checking for loose parts, leaks, and abnormal noises. More in-depth inspections and maintenance like bearing lubrication, impeller cleaning, and vibration testing can be carried out quarterly or annually. Decent company official website: www.scy-fan.com, Contact number: +86-533-5201284, Company email: manager@scy-fan.com. Welcome to consult us.