b'FLOATING BALL VALVES - SLFSBV01 & SLBV01 SERIESNO. DESCRIPTION1 Body2 Cap3 Ball4 Stem5 Seat Ring6 Stem O-Ring *27 Gland *18 Gland Nut *19 Thrust Seal10 Stem Bush/Seal *211 Gland Packing12 Gasket13 Stud Bolt14 Nut15 Stopper16 Snap Ring *217 Lever18 Antistatic Device*1 Gland flange or gland nut in smaller sizes*2 Depends on size & class*3 Snap ring or bolt washer, depending on size/class.FIG 6A. VALVE DESIGN FORGEDThe above is indicative only, design depends on size, class and trim, etc. Refer to as-built drawing.6 . 0 O P T I O N A L A R R A N G E M E N TOPTIONAL DIRECT MOUNT PAD VERSION COMPLETE WITH LIVE LOADED STEM SEALS APV Ball Valves fitted with a direct mount pad often utilise a stem seal arrangement where the seals are retained by a stem or packing nut, with live-loading of the stem seals. This live loading is accomplished by the addition of Belleville (also known as disc) springs below the packing nut . The purpose of live loading the stem seals is to maintain the initial sealing load on the seals as they wear, or as they compress further, reducing or eliminating the need for frequent packing nut adjustments. The Belleville springs perform this function by storing compressive force as the packing nut is tightened, and releasing this force as packing wear or compression occurs.In the cases where they are supplied on APV valves, the springs are installed in series, or stacked with outer diameters touching, rather than in parallel, where the dished springs would be nested together. The arrangement of 2 springs in series provides essentially the same pre-load as a single spring when compressed, and a spring stroke double that of a single spring. Where 2 (or more) springs are installed in parallel, the spring load is the multiple of a single spring times the number in parallel, but the spring stroke is still that of a single spring. For examples, see the following:16 Australian Pipeline Valve - Installation, Operation and Maintenance Manual'