Wiper WNM
WNM wipers are protective seals made of polyamide (PA), a rigid material with distinct mechanical properties compared to polyurethane or NBR. The rigid polyamide profile makes WNM the appropriate choice for situations where the cylinder rod has substantial deposits — light corrosion, limescale deposits, adhering impurities — which the lip of elastomeric wipers cannot remove effectively.
The rigid polyamide profile and the removal of more substantial deposits from the rod surface
Polyamide is harder than polyurethane and NBR, with a rigidity that allows more aggressive mechanical scraping of the rod surface. Where an elastic lip would give way upon contact with adhering or hard deposits, WNM maintains contact and removes the accumulated material. This makes WNM the natural complement to an elastomeric wiper in applications with substantial deposits. You can find the complete catalog of wiper seals on Hydraulic Seals Store.
Situations in which a WNM wiper is preferred over a more flexible elastomeric profile
WNM is selected when the rod has deposits that are not removed by standard polyurethane wipers, when the environment generates crusts or mineral deposits, or when the cylinder operates in applications with hard water or fluids that leave solid residues. WNM does not replace elastomeric wipers — it is installed in combination with them, in separate grooves. Also compare with WDA wipers made of polyurethane for contamination with fine particles.
Checking clearance, diameters, and groove height for correct installation
When installing WNM, the clearance between the wiper and the rod is more critical than with elastomeric wipers, because polyamide does not deform elastically to compensate for dimensional deviations. The rod diameter, housing diameter, and groove depth are checked before ordering. Check that the cylinder has dedicated grooves for both types of wipers. Also compare with WED wipers made of polyurethane available in our catalog.
Selecting WNM wipers according to the dimensions available at Hydraulic Seals Store
We keep WNM wipers in stock in standard sizes. We deliver quickly throughout Romania. Contact the Hydraulic Seals Store team with the groove dimensions to identify the correct product.