Integral Flanged Gate Valve Manufacturer: Class 150LB, Class 300LB, Class 600LB Integral Flanged Gate Valve, 1/2-2 Inch, API 602, ASME BI6.34, BS 5352. Design Construction: API 602, ASME BI6.34, BS 5352 Testing according to API 598 Face to face according to ASME B16.10 Flanges according to ASME B16.5 Marking MSS SP25 Spiral-wound gasket Integral backseat Integral body flanges Outside Screw and Yoke (OS&Y) Self aligning two piece packing gland