API Std 608 pdf download Metal Ball Valves—Flanged, Threaded, and Welding Ends 5.7Packing Glands and Gland Bolting 5.7.1 Adjustable packing glands shall be accessible for resealing stem packing without the disassembly of vaveparts or operator parts. 5.7.2 Packing glands that are threaded into bodies or covers or onto stems shall not be used for valve sizesgreater than DN 80(NPS 3)...