For protecting the shaft against wear and corrosion by the pumped medium. DIN ISO 5199 (February 1987) sets the following requirements for the design and production accuracy of shaft protection sleeves for centrifugal pumps:

"4.11.2 Surface roughness

Provided no other requirement needs to be raised for the shaft seal, the roughness of the … shaft protection sleeve in the area of the stuffing box packing, mechanical seal and bearing flange seals must not exceed 0.8 mm. The surface roughness must be measured in accordance with ISO 3274 (DIN 4772)… 4.11.4 Diameter

The diameter of the shaft or shaft protection sleeve in the area of the shaft seal must conform, as far as possible, with ISO 3069 (DIN 24 960).

4.11.5 Shaft concentricity

The shaft and the shaft protection sleeve … must be manufactured and assembled to ensure that the radial eccentricity (see Section 3.16) in the plane set by the outer end face of the seal housing does not exceed

50 mm for shaft and or shaft protection sleeve diameters smaller than 50 mm, 80 mm for diameters from 50 to 100 mm, and 100 mm for diameters larger than 100 mm …

4.11.7 Fastening and sealing the shaft protection sleeve

If provision is made for shaft protection sleeves, they must be form-locked against twisting and axial movement on the shaft. The shaft protection sleeve must be sealed against the wheel hub to prevent wetting of the shaft.

4.11.8 Arrangement of the shaft protection sleeve, if fitted

Shaft protection sleeves must be of sufficient size for their outer ends to protrude far enough over the used shaft seal (packing stuffing box, mechanical seal and auxiliary seals) to prevent leakage from between the shaft protection sleeve and shaft being mistaken for leakage fluid emerging from the shaft seal.