Australian Pipeline Valve - Installation, Operation and Maintenance Manual 17 SIDE ENTRY 2P TRUNNION BALL VALVES API6D STANDARD - FS9000 SERIES resistant and compatibility to media and temperature flowing through the line. See 8.4.1 for emergency seat sealant if seats leak. c- Also see 8.4.1 for emergency seat sealant injection procedures. 8.3 VALVE OPERATING a- It is advisable, where possible (especially if valve is an actuated ESDV), to move the ball periodically in order to prevent any hard scale or memory lock between ball and seat. b- Partial operating (at least about 5% of the total stroke) every 6-12 months will ensure a good life of seats and ball. This will ensure the valve functions and will prevent seizure/galvanisation of any mating surfaces. Duration depends on service, criticality, etc. However, it also must be factored in that if there are impurities or particulates in the line each operation could reduce seat life proportionately. However immediately fully re-open or fully re-close the valve as partial opening for more than a few minutes will damage the seat. c- Before operating with the valve completely open or closed it is advisable to lubricate the internal components as per point 2.4.3 and 2.6. 8.4 MAINTENANCE SCHEDULE ESTABLISH INTERVALS ACCORDING TO PLANT REQUIREMENTS. a- Stem packing or seal leakage. In case of leakage from stem seal or packing proceed first to inject sealant through the sealant nipple where provided (see 8.4.1 below). If it does not stop the leak, the stem gland seal must be replaced. b- Body-adaptor leakage. If leakage from body and adaptor join occurs, it is necessary to replace the body gasket. c- Seat leakage. In case of leakage from seat rings it is possible to inject special silicon grease into emergency seal injection nipples (see 8.4.1 below). Be sure that the grease pump employed for this intervention is able to give a pressure higher than the pipeline pressure. 8.4.1 Emergency Sealant Injection Procedure A sealant is a heavy grease-like substance used to stop small leakages through sealing surfaces. A slightly damaged or scratched sealing surface can still close if some sealant is injected. Sealant injection is intended for temporary emergency situations, where a major valve overhaul to replace the seats is not possible. Sealant is injected through the grease fittings (36) located in the valve body, near the seat area. Grease fittings are not fitted on all valves as some clients prefer not to have them to prevent the possibility of applying grease unnecessarily which can then attract debris and damage the seat. In smaller size valves there is only a body sealant injection. In this case the valves must be full open during injection, more grease is required as the valve cavity must first fill, then stroke the valve in order to wipe the grease onto the seats. Then repeat the procedure. For normal lubrication see 8.2.