This class 150 Milwaukee P901 series bronze gate valve has a quick-opening stem with a lever handle and female National Pipe Taper (NPT) threads on both ends. The bronze construction of the gate valve and its brass double discs provide higher strength and resistance to corrosion than steel. The valve has a brass quick-opening stem that is manually operated by turning a malleable iron lever handle, which pushes the discs into the valve’s passage to stop flow between pipes. The pressure between the two discs forms a tight seal to stop potentially dangerous fluids from leaking and mixing. With the exception of the 4" valve that has an O-ring, this valve has graphite internal stem packing. The valve has female NPT threads on both ends for connecting to male threaded pipes. The maximum pressure of this class 150 valve is 300 pounds per square inch (gauge) (psig) for water, oil, and gas pressure (WOG) and 150 psig for saturated steam pressure. Class is a standard relating to tolerance, construction, dimension, and wall thickness, but it is not a direct measurement of maximum working pressure. The valve is appropriate for quick draining and steam blow-off use and other heating and plumbing applications.

Gate valves control flow in a piping system by lifting a gate out of the path of steam, fluids, or gases. They are designed to block or permit flow, as the vibrations and force of flow repeatedly striking a partly lowered gate can damage the gate and seats. To accommodate different flows and pressure requirements, gates come in four types: solid wedge (appropriate for almost all liquid service), flexible wedge (appropriate for steam service), split wedge (appropriate for normal temperature, non-condensing gas and liquid service, including corrosive service), and parallel disc (appropriate for high and low pressure applications). Hand wheels or levers activate the screw mechanism in the valve’s bonnet, which comes in various designs, to open and close the gate. Union bonnets are preferable for building service piping, threaded-in (or screw-in) bonnets work well for lighter-duty usage, and bolted body-bonnet connections are used primarily in iron multi-turn valves. Most gate valves have either a rising stem, which moves up and down with the gate, or a non-rising stem, which remains fixed in place. When closed, the gate and its seats form tight planar sealing surfaces, ideal for linear liquid flow. Gate valves are used in air, gas, liquid, and steam applications.

The Milwaukee Valve Company manufactures manual and actuated valves, controls, and control accessories. The company, founded in 1901, and headquartered in New Berlin, WI, meets International Organization for Standardization (ISO) 9001:2008 and 14001:2004 standards.