AWWA C500 OS&Y Metal Seated Gate Valves

Main Design Features

SJZ Metalsin supplies AWWA C500 OS&Y rising stem metal seated gate valves for water supply service. These valves have the same metal-to-metal seals as that of the NRS metal seated gate valves, which are formed between a pair of accurately machined copper alloy seat rings seated/mounted in the body and wedge respectively. The closure member of the gate valve is usually a solid hollow gate in wedged shape, using two inclined seats  and a slightly mismatched inclined gate to secure tight shutoff, even against higher pressures. The body and bonnet are made of ductile cast iron (ASTM A536 Gr.65-45-12)or grey cast iron (ASTM A126 Gr.B). Both the interior and exterior surfaces of the valve are fusion bonded epoxy (FBE) coated in accordance with AWWA C550. The AWWA C500 OS&Y rising stem metal seated gate valves are available in sizes 2″ through 48″, meeting the design working water pressure 250 psi. They are usually furnished with flanged ends, which are made in accordance with ASME B16.1 Class 125, or other standards upon purchaser’s request.

The AWWA C500 metal seated gate valves with OS&Y rising stem design (the yoke is bolted onto the bonnet), 16″ 250 psi in assembly workshop, delivered to Manzanillo, Mexico.

The most notable design feature of these valves is the OS&Y rising stem. In the rising stem design, the wedge is fixed to the valve stem. As the handwheel is turned, the threads (which are located above the packing box) retract the wedge from the flow stream, causing the threaded portion of the stem to rise above the handwheel. “OS&Y” stands for “outside screw and yoke”. In an OS&Y gate valve, the threaded stem is located outside the valve body. When the valve is operated, the stem moves up and down outside the valve body, making it easy to see the position of the valve (open or closed) based on the stem’s position. The yoke is a structure mounted/bolted on the valve body that supports the stem. It provides a guide for the stem to move vertically and ensures proper alignment during operation. The OS&Y rising stem design allows easy visual indication of the valve’s open or closed position. It reduces wear and tear on the stem threads while simplifies maintenance.

Material Selection for Main Parts

Figure-1: The typical photo & G.A. drawing of AWWA C500 OS&Y rising stem metal seated gate valve, handwheel operated, applicable to 2″~12″.

Basic Dimensions

Figure-2: G.A. drawings for AWWA C500 OS&Y rising stem gate valves with bare stem or bevel gear operator, respectively. Applicable to sizes 14″ and above.