In order to reduce initial cost, especially for large diameters, coated plungers are often used in the 1st stage cylinders of hyper compressors instead of solid carbide plungers. CTD manufactures new plungers with HP-HVOF carbide coatings. For these plungers we use high-strength-low-alloy steel with a very high purity in order to guarantee the best possible fatigue resistance. Damaged or worn out coatings can also be repaired by replacing the old coating by a new one. This is very cost effective and can be done in a short delivery time.
The same carbide coatings are also used on piston rods for primary and other reciprocating compressors.
Primary compressor piston rods are heavily loaded machine parts. CTD manufactures these piston rods to the most stringent specifications Special fatigue resistant steels, rolled threads and surface treatments on the piston grooves are some of th features used in order to guarantee a long lifetime. All the piston rods are coated with HP-HVOF carbide coatings in order to obtain the best wear resistance in combination with long service life of the sealing and wiper rings. This is also obtained by adapting the surface profile and roughness to the lubrication and type of seal rings.
The development of an HVOF coating system to coat nano-powerds made it possible to apply HVOF carbide coatings on compressor liners. This development improves the life time of compressor liners considerably. The better wear resistance also reduces wear on piston rings and rider rings and will reduce leak gas and oil consumption. Internal diameters as small as 80 mm can be coated.