Piston rods or plungers are mostly uncoated/hardened or chromed with a ca. 25µm galvanised coating as standard. The chromed coating has micro cracks and is too small with aggressive media which means underlying corrosion and premature wear could occur.
For piston rods (plungers) basic components like cast steel/steel or stainless steel are commonly used. We have been using individual alternative coating methods to hard chroming, such as powder flame spraying with self fluxing NiCrBSi, HVOF, wire flame spraying for decades.
Part of this flame spraying method enables distortion-free and basic component neutral piston rods/plunger coating. These are exceptionally suited for repair and installation, when strong shrink marks or pitted places have occurred.
The Piston rods/Plungers are then turned clean by us for repair or ground and then upholstered according to the coating strength. The element is then galvanised with hard chrome or hard metal coating. We can make those coatings gas dense/tight with special solutions.
In flame spraying we dispose many coating agents which serve both as corrosion protection and wear protection of the piston rod/plunger.
The coating strength for piston rods/plungers is often 150µm to 2000µm.
Flame spraying and its method is characterised by the fast and uniform coating build-up, which we carry out for our customers as a qualified, certified and flexible specialised coating company.
Flame spraying provides an alternative and advantages to galvanising and hard chroming of piston rods and plungers. We will be happy to provide you with free advice.