b'SIGHT GLASSES - SLSG SERIES DURING OPERATION TAKE INTO ACCOUNT THE FOLLOWING WARNINGS:a- Graphite body gaskets are very brittle, any impacting, twisting or bending should be avoided. PTFE gaskets must not have any scrathes to surface.b- The sight glasss internal parts such as flow indicator, pin & gasket shall be handled with care.c- All tools and equipment for handling the internal parts shall be soft coated. d- Valves can be fitted with gaskets or seals in PTFE, Buna, EPDM, NBR, Viton, etc., hence chemicals or high temperatures will damage sealing components.For all operations make reference to position number on part list of the applicable drawing listed.Bonnet seal could result in personal injury. Bonnet is tightened prior to shipping but may require replacement seal or tightening to meet specific service conditions.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 sight glass from the system and relieve pressure prior to performing maintenance.Disconnect any operating line providing air pressure, control signals or electrical power to actuators.If a gasket seal is disturbed while removing or adjusting gasketed parts, APV recommends installing a new gasket while reassembling. A proper seal is required to ensure optimum operation.4 Australian Pipeline Valve - Installation, Operation and Maintenance Manual'