b'MULTI-WAY BALL VALVES - BV509/509A, BV2057, BVL50~L54, SL8142-FZ SERIESLIQUIDS WITH HIGH FLUID VELOCITYWhen ball valves must be operated frequently on liquid with very high velocity, check with manufacturer for appropriate advice to minimise the possibility of seat deformation, especially when working pressure and temperature is reaching maximum ranges.Avoid using the valves at partially open or partially closed position. Using partially opened valves may lead to seat deformation and leakage. Standard ball valves are generally not recommended for throttling service. The fluid flow can damage the leading edge of the ball and/or damage or deform the resilient ball seats causing leakage. High fluid velocity and/or the presence of solids particles in the media will reduce the lifetime of seat and ball during throttling applications.3.3 AUTOMATED OPERATIONSValves with actuators should be checked for actuator/valve alignment. Angular or linear mis-alignment will result in high operational torque and permanent packing failure. Refer to as built drawing for theoretical torque ratings which are subject to variations depending on the length of time between cycles and the media in the system.Breakaway torque is that force which must be exerted to cause the ball to begin to open. Operating torque requirements will vary depending on the length of time between cycles, media in the system and line pressure. As actual torque test should be done at full differential pressure before sizing actuator media type, lubricity & temperature should be factored in.4 . 0 M A I N T E N A N C EOnly APV approved repairer should attempt to perform work on APV valves.Valves should be periodically checked at least once every 3 months, but depending on service, criticality and frequency of use, more regular checking may be required.Packing leakage could result in personal injury. Valve packing is tightened prior to shipping but may require adjustment to meet specific service conditions.If valve does not fully close, damage to the seat and body will result due to the venturi effect resulting in high pressure erosion. Flush or remove the valve at next opportunity.Flowturn - Installation, Operation and Maintenance Manual 11'