This class 300 Milwaukee Valve 1186 series bronze gate valve has a non-rising stem and female National Pipe Taper (NPT) threads on both ends. The bronze construction, solid wedge gate, and union bonnet provide higher strength and resistance to corrosion than brass. The stainless-steel seat rings equip it for high pressure applications and help resist corrosion over time. It has a non-rising stem that stays fixed in place when gate is raised or lowered for low clearance or underground use. The graphite internal packing helps prevent the valve’s stem from leaking. The maximum pressure is 1,000 pounds per square inch (gauge) (psig) for water, oil, and gas pressure (WOG) and 300 psig for saturated steam pressure. It has female NPT threads on both ends for connecting to male threaded pipes. Mounted on top of the valve, a manually operated malleable iron hand wheel activates the inside screw mechanism which lifts and lowers the gate to start and stop the flow between the connected pipes. This class 300 valve meets Manufacturers Standardization Society (MSS) SP-80 for quality assurance. 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 use in heavy duty service in plumbing and heating systems.

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 disk (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.