Design
Cast steel check valve has been designed to conform to BS1868, API600, and ASME B16.34. Wall thickness dimensions comply with API 600. Face to face, end to end, and center to face dimensions of flanged and butt welded valves are in accordance with ASME B16.10, BS 2080 and ISO 5752. End flange dimension conform to ASME B16.5 for sizes NPS 24 and smaller, ASME B16.47 series A for sizes NPS 26 and larger. BWend dimension conform to ASME B16.25. Inspection and test are in accordance with API 598 and BS EN 12266.

Body and Bonnet
Castings are precisely machined. A flat face gasket joint is used in the 150 lb. A male and female joint is used in 300lb, 600lb. Ring joint is used in 900 lb and higher. The gasket contacting surface is smooth finish that has a roughness between Ra 3.2 and 6.3 micrometer (125-250microinch). The surface roughness of gasket grooves of ring joint faces do not exceed 63 micro inch. Body seat construction of cast steel valve has three types: threaded seat ring, welded seat ring and integral seat ring. Disc shaft does not penetrate body. Provided with bosses for optional by-passes or drains.

Disc Assembly
Disc is fastened securely to disc hanger with a lock nut and cotter pin. Disc is free to rotate to avoid localised wear. All parts are accessible from top for easy servicing.

Cover Gasket
Class 150-600: Jacketed graphite with stainless steel or spiral wound graphite with stainless steel . Class 900 and over: Ring joint metal gasket.

Cover Bolting
Coarse thread series for bolt sizes 1 inch and smaller,8-thread series for bolt sizes 1 1/8 inch and larger, both conform to Class 2A/2B tolerances.