b'MULTI-WAY BALL VALVES - BV509/509A, BV2057, BVL50~L54, SL8142-FZ SERIESb. After long-term valve operation and endurance of force, the ball seat or the ball can become scratched and therefore leakage occurs. Replace seats. Also, refer sections 4, 5 & 6.4.4.1 DisassemblyRefer Appendix B to E for indication of parts. Refer to as-built drawing from APV for actual bill of material.a. Place valve in half-open position and flush the line to remove any hazardous material from the valve body.b. Place the valve in close position, remove both counter flange bolts & nuts and lift valve from line.c. Remove handle nut, handle or actuator set, stop-lock-cap (where applicable), stem nut, Belleville washer, gland nut, bush and stem packing.d. Remove body bolt or threaded end cap to allow end cap to be separated from body, remove body gasket.e. Make sure ball in closed position, thus the ball can be taken out easily from body, then take out body ball seat.f.Push stem down into the body cavity and remove, then remove the stem seal-ring and V-stem packing from the body.Use care to avoid scratching the surface of stem and packing chamber.4.4.2 Reassemblya. Reassembly process is reverse sequence of disassembly.b. Clean and inspect all parts, full replacement of all soft parts (seats and seals) are strongly recommended.c. Tighten the body bolt or screwed end cap crosswise (in the case of flanged body design) using the stipulated torque figure (see Appendix A).d. Tighten the stem nut (using the stipulated torque figures (see Appendix A).e. Cycle the valve slowly with gentle back and forth motion to build gradually to full quarter turn.f.Test the valve before placing it back in the line for service.Flowturn - Installation, Operation and Maintenance Manual 15'