GATE VALVES - STANDARD FEATURES

1. FLEXIBLE GATE
   A flexible wedge is a one piece and fully guided cast with a central hub allowing the seating faces to move reciprocally and thus compensating for the distortion on body seats due to thermal expansion or pipe loads. Seat ring and wedge seating face are set to 9° angle from the vertical to minimize the sliding contacts between wedge and seat ring while opening or closing them.
   Wedging helps lead to a tight seal in a low differential pressure service. A flexible wedge resists wedge sticking or binding in a service. The wedge may be closed in a hot condition and opened in cold. The seating surfaces are stellited to provide high cycle capability in a very high differential pressure service.
    
2. STANDARD PRESSURE SEAL DESIGN
   A segment thrust ring absorbs all the thrusts applied by internal pressure. A protective ring made by hardened stainless steel prevents the deformation on the top surface of soft metal gasket. The gasket can be removed smoothly without any damage on the sealing surface of body.
    
3. PACKING ADJUSTMENT
   All gate and globe valves have a two-piece packing gland to minimize the scoring on valve stem which may occur if tightened unevenly. Gland bolts remain fastened to the bonnet. They swing out of the way to simplify the packing replacement and are
   oriented to adjust the packing from one side of valve.
    
4. DEEP STUFFING BOXES
   Deep stuffing boxes are standard type for gate and globe valves. They allow for extra packing to ensure more reliable stem seal and sufficient packing depth containing an optional lantern ring in the middle of box. Where lantern ring is included, a tapped and plugged hole is made. If specified, a ball grease injector can be fitted with.
    
5. BEARING INSERT TYPE YOKE SLEEVE
   Large and high pressure valve may require a tremendous amount of torque to open or close the valve. Ball bearing in the yoke sleeve will reduce the operating torque of valve by up to 50 percent.