BS 5163 NRS Metal Seated Gate Valves

Design Characteristics & Benefits of Metal Seating

Figure-1: the photo & drawing of BS 5163 NRS metal seated gate valves, handwheel operated.

SJZ Metalsin supplies BS 5163 metal seated gate valves made of grey (flake graphite) cast iron or ductile (spheroidal graphite) cast iron. These valves shall be furnished with non-rising stems (NRS) and are usually handwheel operated. The closure member shall be a wedged gate, either a flexible wedge or solid wedge. The valves shall be furnished with flanged ends, the dimensions of which shall be in accordance with BS 4504, EN1092-2, BS 4772, or BS 10, etc. The BS 5163 NRS metal seated gate valves are available in sizes covering DN50 to DN600 and in nominal pressures PN10, PN16 and PN25. As illustrated in Figure-2, a pair of bronze alloy seat rings are inserted/embedded respectively into the wedge-shaped gate and the recess of the cast iron valve body to serve as the valve seats. Their sealing surfaces are precisely machined. When the handwheel is turned to close the gate valve, the seating surface of the bronze seating ring on the wedge gate presses against that of the inserted seat ring in the valve body, causing the metal-to-meat contact, forming a watertight seal.

Figure-2: illustration of the metal seating design for the BS 5163 NRS gate valve: 1 – wedge-inserted seat ring; 2 – wedge; 3 – body-inserted seat ring; 4 – body.

Metal seating in BS 5163 NRS gate valves offers numerous advantages, including enhanced durability and longevity due to high resistance to wear, abrasion, and temperature fluctuations. These valves provide a reliable, leak-tight seal through precisely machined metal surfaces, suitable for high-pressure applications. Compared to resilient seated gate valves, their robust construction reduces maintenance needs and allows for field repairs, making them cost-effective over the long term. Additionally, metal-seated valves handle various media types, provide bidirectional sealing, and can be integrated with manual or automated actuators, ensuring versatile and reliable performance in demanding environments.

Material Selection & Structural Dimensions