Drill pipes are essential for transmitting drilling fluids and rotational force from the surface to the drill bit. High-strength steel alloys are commonly used for drill pipes due to their ability to withstand high torque and pressure.
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.


Type of Fluid
Seals are classified by O.D. wall material, lip type, and whether they have a spring or not.
Major oil seals are specified in ISO 6194-1 and JIS B 2402-1.
Table 2 shows the common types of oil seals, while Table 3 shows the features of each type of oil seal.
Table 4 lists the JTEKT oil seal type codes and corresponding ISO and JIS standards.

The most important function of an oil seal is to protect all types of sleeves, roller bearings, and balls located in the rotary shafts. These seals also prevent two fluids from mixing, such as water and oil.


Aspects to consider when selecting oil seals
The oil seal is our first line of defense in regards to keeping lubrication inside the reducer. It might also be described as the last line of defense – keeping contaminants outside the reducer where they belong. The average seal is incredibly simple in design – made up of a case, a lip or lips, and frequently a garter spring. Of course, some are exponentially more intricate and are manufactured with unusual materials, but the majority are straightforward.
There is a British Standard laid down for the control of synthetic rubbers. BS 3574 (1989) helps to determine shelf life – for instance, Nitrile (NBR) and Polyacrylic (ACM) are Group ‘B’ rubbers and have a 7-year life, whilst Silicone (VMQ) and Fluoroelastomers (Viton®) are Group ‘C’ rubbers and have a 10-year shelf life. PTFE and Leather do not come into this category but like the others should be kept in the original packing for as long as possible away from direct light, dust, and humidity. Ozone, which can also be produced by battery-driven forklift trucks has a very bad effect on synthetic rubbers. Finally, protect the sealing lip – DO NOT hang the seals on nails, wire etc.
Use an old screwdriver or scraper to carefully remove all traces of the old gasket from the cover and engine flanges.