Backflow Prevention Swing Check Valve H44T DN250 PN16 QT450 Ductile Iron Flanged Round Body

The H44T DN250 swing check valve is a flanged non-return valve manufactured with a QT450 ductile iron (GGG50) body and a precision-machined copper alloy seat ring. It is designed to prevent reverse flow in horizontal water pipeline systems where reliable one-way media movement is required. The round-body casting distributes pressure evenly across the shell, while the swing disc opens fully under forward flow to keep head loss low and closes automatically the moment flow reverses. Every DN250 valve is produced to the Chinese national standard with flanged end connections, making installation straightforward on both new projects and retrofit pipelines. YUXIN manufactures this DN250 model with a full machining and hydro-testing procedure so that each piece delivers dependable sealing and a long operating life in municipal, industrial and commercial duty.

• QT450 Ductile Iron Body: The GGG50 spheroidal graphite iron shell provides high tensile strength, good impact resistance and excellent corrosion resistance compared with grey cast iron alternatives, which suits buried and outdoor water lines.
• Copper Alloy Seat Ring: The replaceable copper seat creates a tight metal-to-metal seal with the disc, reducing leakage and resisting erosion from sand and suspended particles in the water.
• Round Body Design: The streamlined round-body casting avoids sharp internal corners, keeps the flow path clean and minimises pressure drop across the valve during normal operation.
• Swing Disc Mechanism: The hinged disc opens wide under forward flow and falls back by gravity when flow stops, giving automatic backflow protection without springs or external power.
• Flanged End Connections: PN16 flanges with standard drilling allow direct bolting to GB, DIN or ANSI pipework using conventional gaskets and fasteners, simplifying site assembly.
• Strict Quality Control: Each casting is shell-moulded, heat treated and hydrostatically tested; the sealing surface is machined and lapped to meet the national standard leakage class.
• Factory Direct Support: As a manufacturer, YUXIN offers customised DN250 sizes, special flange drilling and batch supply with stable lead times for contractors and distributors.

The DN250 H44T check valve is widely used in water supply and drainage networks, water conservancy projects, building services, chemical plants, petroleum facilities, pharmaceutical workshops, sewage treatment stations and power generation systems. In a pumping station the valve protects pumps from reverse rotation and water hammer when the pump stops; in a distribution main it prevents backflow between pressure zones; in an industrial process line it keeps media flowing in one direction to protect filters, meters and heat exchangers. The corrosion resistant ductile iron body and copper seating also make the DN250 model suitable for raw water, treated water and mild effluent duties where dependable shut-off against reverse flow is essential.

Each DN250 valve is wrapped with flange covers to protect the sealing faces, then packed in a standard export carton or plywood case with foam cushioning according to the valve weight and shipping route. YUXIN holds ISO 9001:2015 quality management certification and performs 100 percent shell and seat pressure testing before dispatch. Samples are welcomed for evaluation, and the factory can adjust DN250 dimensions, flange drilling and surface coating on request. For detailed drawings, test certificates and quotation, please contact our export team directly.