Product Description Design Construction and Specification: Gate valves conform to API 602, BS5352, and ASME B 16. 34, Each are tested according to API598, and marking is per MSS SP-25. Construction is as follows: Outside Screw and Yoke (OS&Y) Two Piece self aligning packing gland Bolted bonnet with spiral-wound gasket, threaded and seal welded bonnet or threaded and pressure seal bonnet Inner Packing: Plastic Packing Outer Packing: Veneer case for sea transportation Integral backseat Socket weld Ends to ASME B16. 11 Screwed Ends (NPT) to ANSI/ASME B1. 20.1