A BS 1873 Control Valve is a valve designed to meet the specifications outlined in the BS 1873 standard, which defines requirements for outside screw and yoke valves made of cast or forged carbon and alloy steel. These valves can have straight, angle, or (oblique) Y patterns, with flanged or butt-welding ends, ranging in nominal sizes from 15 mm to 400 mm (1/2 inch to 16 inch) and Classes 150 to 2500. Additionally, the standard can be adapted for valves with needle type seats in smaller nominal sizes. These valves are utilized to regulate fluid flow, including gas, oil, water, and steam, within industrial processes. Serving as a pivotal component of a control loop, the Control Valve functions as the primary final control element in various industries, ensuring precise control over fluid flow rates and pressures.