There are quite a number of factors to put into consideration when you’re choosing the right oil seal for your application. Some of them are discussed below.

Once you have selected the most suitable seal available, considering the environment, temperature, shaft speed, pressure, lubrication availability, as well as the size, of course, the seal should be stored adequately and then fitted properly. Here are a few suggestions that could help:-
Orient your seal the same way as the initial install.The sealing lip should face the lubricant that requires sealing.The second lip on a double lip oil seal is intended as a dust lip. The seal must be installed at a 90°, or perpendicularly, to both the shaft and housing bore. This is an issue in cases where the housing does not have a counterbore or shoulder the seal can seat up against.
The sealing lip of the RST-D is more heavy-duty, so it can cope with pressures of up to 10 bar at slightly lower rotation speeds.
The maximum allowable shaft speed is a function of the shaft finish, runout, housing bore and shaft concentricity, type of fluid being sealed and the type of oil seal material.
PTFE
MVQ
Air side face The oil seal surface vertical to the center line of the shaft on the side that does not come in contact with substances to be sealed is called the back face.