DUCTILE IRON PRESSURE REDUCING VALVE – PILOT TYPE FOR STEAM MODEL : PIR-1F / PIR-2F Product Descriptions  · The mechanism that automatically adjusts the pressure in pressure reducing valves uses the balance between the steam pressure and the adjustment spring. · The steam flowing through the pilot valve is controlled by the balance between the adjustment spring and the secondary pressure. · This steam causes the piston to fall and rise, which controls the amount of opening of the Specifications Brand : YNV Model : PIR – 1F , PIR-2F Size : DN 15A → DN 250A ~ (1” inch → 10 ” inch) Origin Korea