b'MULTI-WAY BALL VALVES - BV509/509A, BV2057, BVL50~L54, SL8142-FZ SERIES4.1.1 Stem LeakageStem Packing ReplacementThe most common point for leakage is around the stem and packing this leakage can normally be stopped by adjustment of the packing gland. If this does not stop the valve leakage, the valve will have to be repacked.The system and valve MUST be depressurised before attempting any repair work. After removing all pressure from the valve and draining the system the following procedure should be used to repack the valve.1.Remove nuts or screw from the lever. Remove the lever and lock plate. Remove the gland plate bolts or nut and remove the gland plate and gland. If the gland retainer is a double nut type then remove both nuts and anti vibration washer.2. Remove old packing with the proper tool, taking care not to scratch or damage the stem of stuffing box. Note, the stem design is anti-blow out so the stem cannot be removed up through the top of the valve.3. Clean and inspect stem, stuffing box, and gland. If any scratches, nicks, or corrosion is found, the parts should be replaced.4. Slide each packing ring over the stem and into packing chamber. Ensure if v-type PTFE packing set, the packing is correct way up. See figure 5A. If v-type packing, a genuine packing set must be used. Carefully tap each ring into place and continue installing rings until the recommended number of rings have been installed. A thin smear of molybdenum sulfide anti-seize grease may be used on the stem and packing chamber wall for packing lubrication.5. Replace gland, gland, and gland plate bolts or nut. Tighten until a reasonable torque is applied to lightly compress packing. Lubricate stem and cycle valve through a couple of complete cycles.6. If slight stem leakage occurs after system is pressurised, continue tightening gland until leakage stops. There is also a PTFE seal ring/bearing and an elastomer o-ring. However, these parts can only be replaced during complete disassembly of the valve. Should replacement of packing fail to prevent the leakage, complete reconditioning of the valve may be required.Examine the disc springs (Belleville washers) for damage. If in good condition, tighten the gland nut until disc springs are firmly compressed, then back the nut off 1/16th of a turn. If damaged, dismantle the stem down to the gland, fit new disc springs with their outer edges touching, replace and retighten using the gland nut. Further maintenance necessitates dismantling of the valve.Personal injury may result from sudden release of any process pressure. APV recommends the use of protective clothing, gloves and eye wear when performing any installation or maintenance. Isolate the valve from the system and relieve pressure prior to performing maintenance. Disconnect any operating lines providing air pressure, control signals or electrical power to actuators.Flowturn - Installation, Operation and Maintenance Manual 13'