Shutdown Maintenance
1. If the device is required to shut down,  if the components are shutdown for short-term (2-3 days), they can run for about 30 ~ 60min every day to prevent bacterial contamination.
2. If the components are shutdown for long term( more than 7 days), before SFP device is stopped, it shall be backwashed with air-water , and shall be filled with protective liquid( 1% sodium hydrogen sulfite solution with 10% propylene glycol), close all the inlet and outlet valves of SFP device. They shall be inspected once in a month, and the environmental temperature shall be controlled to 5～35℃.
3. If SFP device has been shutdown for long time and is put into operation again, it shall be continuously flushed until no foam is found in the drainage water.
4. During shutdown time, the ultrafiltration membrane shall be kept wet, in case it is dewatered and dried, it will be irreversibly damaged.