Extreme cleanliness is essential during installation. At all costs avoid applying force, as any deformation of seal or connection parts will jeopardize the proper working of the seal. If installing the mechanical seal entails pushing it over lugs and shoulders, they must be chamfered and sharp edges deburred. The faces, over which O-rings slide, should have roughness values Rz £ 5mm, All installation dimensions must be checked. In the case of seals dependent on the direction of rotation (conical spring, pumping screw), the direction of shaft rotation has to be checked. Special-purpose seals are installed by referring to the installation diagram, which should specify the necessary screw torques and prescribed tolerances of position. Eliminate any sources of vibration. Observe the position of connections. Water, silicon oil or ethyl alcohol (note resistance of elastomers) can be used as an installation aid to reduce frictional forces on O-rings. Resin-free mineral oils can also be used except with ethylene propylene O-rings. Each time the seal is changed, replace O-rings and small parts such as screws and springs as well.