Felt seals are in the shell of tank filled with felt ring seal.

In the contact type sealing devices, felt seal is the most simple form, it is widely applied to low speed, ambient temperature, atmospheric motors, gear boxes and other machinery, used to seal butter and oil. Felt seals for dust-proof, but it shouldn't be used as a gas seal. Felt seal when used as fluid sealing, medium viscosity, the larger the better seal effect, less viscosity liquids such as kerosene, felt the sealing effect is very poor. Felt seal if you use thick felt, then the circumference of the shaft speed is allowed only in 3 m/s, if quality Batt, speed can be 2-3 times, but not more than 10 m/s. If properly designed, and axis of high hardness, good surface finish, lubrication fully, then, in individual cases under the felt seals can also be of 20 m/s high-speed work. Felt seal temperature is generally not exceed 90 ℃, working pressure is one atmosphere. Packing seal on the shaft and housing (packing box) winding between packing, and then use the gland and screw tight. Packing seals are widely used in all kinds of pumps (pumps, vacuum pumps, and so on) seal used for sealing device for liquid or gaseous media