LDPE plants operate at pressure levels up to 3500 bar. This requires the highest possible quality in manufacturing and refurbishment of hyper compressor cylinder components Small details during manufacturing, reconditioning or repair of the cylinder components often make the difference between safe operation and catastrophic failures during operation. Being aware of these details requires a lot of experience and comprehensive know-how. Critical details in proper material choice, correct use of measuring and inspection techniques, high precision machining, use of special surface treatment technologies, finishing techniques, handling and packing, are discussed based on 2 examples: the manufacturing and reconditioning of carbide plungers and the manufacturing and reconditioning of packing cups.