How to install the O-ring
1- Check the O-ring surface;
2- Take O-ring into hot water when the room temperature is low;
3- Can add some water, detergent, silicone oil to lubricate O-ring;
4- Select the 4 to 6 points of large O-ring, which was first placed in the tank, and then press other into the tank. Otherwise it will cause the O-ring is stretched.