Forged steel, a basic material for control valves has now a new competitor – casting material. The latter allows manufacturing of control valves with a higher density (oder impermeability) as well as exact and constant quality control characteristics.
Raw material required for producing hydraulic and control valves are aluminium, forged steel, black and nodular-graphite cast iron. Primarily, the choice of the suitable material is determined by intended function. For mobile-hydraulic purposes, light material units are required with a possible light-weight. On the other hand, metal-spinning operations over 400 bars require normally forged steel.
Nowadays, forged steel could be substituted by all means through cast iron. Gontermann-Peipers (GP) in Siegen offers an alternative to alloyed lead- machining steel or Hyt 60 as well as cast iron (Gopag C 500 F) as further forge material. The pure ferrous substance having a grade under 190 HB corresponds from the processing parameters’ point of view to those of GJS 400, thus enabling utilization for larger valves. Owing to the possibility of ultra sound-analysis as well as extraction of samples from the middle valve, it’s a safeguard against fallout.
GP manufactures high number of control valve units out of strand-casting with exact specification for large-volume production. For valves with standard basic material GJS 400-18, clients choose the desired properties to be complied with, with the help of a material-data sheet and according to needed functional applications. An operating procedure is set up together with the client to serve a 100- percent-ultra sound analysis. During this analysis, several graphite pebbles which are either too big or tightly stuck together fall down, The result of all those measures shows that the finished control valves feature a high density and exact and constant quality control characteristics.
GP holds a stock of about 5000 tons of standard material in GJL and GJS. Due to preliminaries such as sawing, milling and pre-drilling, clients very easily make their orders and reservations for the desired rods or valves over the GP-Online system.