Gate Valve Body Structure: Manufacturing Methods and Bore Designs

The design of a gate valve body is determined by its connections to the pipeline and the valve bonnet. Common manufacturing methods include casting, forging, forged-welding, cast-welding, and pipe plate welding. Notably, forged valve bodies are trending toward larger diameters, while cast valve bodies are increasingly used for smaller diameters. The choice between forging and casting for any valve body depends on specific user requirements and the manufacturer's production capabilities.The main gate valves product names of China gate Valve Network include:Rising Stem Double Disc Parallel Gate Valve,Rising Stem Wedge Single Disc Gate Valve,Stainless Steel Wire Port Gate Valve,Sprocket Wafer Knife-shaped Gate Valve,Sprocket Slurry ValveSCZ Series Flashboard Valve,Slab Gate ValveScum Flange Gate Valve,Stainless Steel Flange Gate Valve,Wafer Bevel Gear Knife-shaped Gate Valve,Z41H Manual Flange Cast Iron Gate Valve,ZT9928 Manual Slurry Knife-shaped Gate Valve,Z40/540/940H/Y Cast Steel Pressure Self-tight Gate Valve,

Gate valve bores are classified into two types: Full Bore (Full Port) where the passage diameter is essentially equal to the valve's Nominal Diameter (DN), and Reduced Bore (Reduced Port) where the passage is smaller than the DN. Reduced bore designs can be either Uniform Reduction or Non-Uniform Reduction (Tapered Bore). A tapered bore typically starts near the full nominal diameter at the inlet and gradually narrows to its smallest diameter at the valve seat.

Using a reduced bore design (tapered or uniform) offers a key advantage: it allows for a smaller disc size, thereby reducing the required opening/closing force and torque for valves of the same nominal size. The trade-off is increased flow resistance, leading to higher pressure drop and energy consumption, so the reduction should be limited. For tapered reductions, the seat inner diameter to nominal diameter ratio is typically 0.8 to 0.95. Common practice is: for valves below DN 250, the seat bore is usually one standard size smaller than the DN; for valves DN 300 and above, it is usually two standard sizes smaller.

Keywords: Gate Valve Body, Forged Valve, Cast Valve, Full Bore Valve, Reduced Bore Valve, Nominal Diameter (DN), Flow Passage, Valve Seat, Opening Torque, Pressure Drop.