The valve shall be made with high hydrodynamics section globe body, without stagnation pockets (conical, low pressure loss type), the main valve body and cover shall be made in standard ductile cast iron casting GJS500-7 and the valve body and cover shall be protected by 200° C furnace polyester resin powder painting with 150 micron of minimum guaranteed thickness.
The seal seat, stem and return spring shall be made in in stainless steel for better cavitation resistance, and the plunger seal disc shall be entirely guided and indipendent of the seal seat.
The valve shall be made with a free open passage wider than 80% of nominal diameter and neither spoke nor grid shall be interposed in the flow path. The valve shall be equipped with removable stainless steel seat disc; it shall be possible to insert an optional V-PORT plunger instead the standard one, without valve modication, in order to dissipate high pressure. The valve shall be made with a spring placed in the control chamber. The spring shall not be in direct contact with main flow. The valve shall be equipped with position indicator. The diaphragm shall be made in nylon renforced Buna-N, on request Viton diaphragm for petrolchemical use, and the seal disc shall be made in Vulcolan, or Viton on request. For easy maintenance it shall be possible to have access to internal parts without removing the valve from the pipeline and to intervene on pilot circuit even with operating valve.