AS 4617 pdf download

AS 4617 pdf download.Manually operated gas valves
2.1 MATERIALS
2.1.1 Continuity of satisfactory operation Materials used in the construction shall be such that continuity of safe and satisfactory operation can be expected during normal usage within the manufacturer’s specification. 2.1.2 Suitability of materials for conditions of use Materials and finishes, including dressings and lubricants, used in the construction, shall be suitable for the conditions of use, e.g. corrosion, temperature, handling. 2.1.3 Materials in contact with gas Materials in contact with the gas, including lubricants, dressings and jointing compounds, shall be suitable for use with all gases. 2.1.4 Melting point of metallic materials Metallic materials shall have a melting point not less than 430°C. Conformance shall be assessed by testing in accordance with the method in Clause B4 of Appendix B. 2.1.5 Copper containing alloys Components made of copper containing alloys shall be resistant to stress corrosion cracking when tested in accordance with ISO 6957 or AS 2136.
2.2 CONSTRUCTION
2.2.1 Continuity of satisfactory operation Construction shall ensure continued safe operation during usage within the manufacturer’s specification. 2.2.2 Castings and hot pressings All castings and hot pressings shall be clean and sound, free from laps, blow holes and pitting. All surfaces not machine finished shall be clean, smooth and free from sand. 2.2.3 Sealing of porous castings or cracks Porous castings or cracks in gas-carrying parts shall not be sealed other than by an accepted method for the impregnation of castings, e.g. vacuum impregnation. 2.2.4 Assembled valves to be clean The assembled valve shall not contain dirt, casting sand, swarf or other foreign matter. There shall be no excess diaphragm dressing, lubrication or jointing compound in the valve. 2.2.5 Accidental displacement of parts Every part shall be secure against accidental displacement. Every part shall be constructed to maintain a fixed relationship between essential parts under normal and reasonable conditions of handling and usage so as to ensure continued conformance with this Standard. 2.2.6 Attachment of knobs, handles, dials and pointers Knobs, handles, movable dials and pointers, where supplied, shall be securely attached to their spindles.2.2.7 Springs Springs shall be resistant to corrosion. The coils of a helical spring shall not overlap at any position during the operation of the valve. 2.2.8 Securing of parts together Adhesives shall not be used for securing parts together without additional mechanical fixing means, except for labels. 2.2.9 Sharp edges Exposed parts in the installed position shall be free from sharp edges that may cause damage or injury. 2.2.10 Valves incorporating a means of ignition Where a means of ignition is incorporated with a valve, the valve shall be sufficiently robust to prevent distortion or damage in performing this additional operation. 2.2.11 Means of limiting the travel of manual valves The means of limiting the travel of a manual valve shall be such that it cannot be displaced or damaged. 2.2.12 Holes for assembly or mounting Holes intended for the assembly of parts or for mounting shall not open into gasways. Holes shall provide a minimum wall thickness of 1 mm from gasways. 2.2.13 Permanent sealing of non-functional holes Non-functional holes used for manufacture and which form a passage between gasways and the atmosphere shall be permanently sealed by mechanical means. 2.2.14 Self-tapping screws Self-tapping screws, other than those that form a fully swaged machine type thread, shall not be used to secure together the external joint of a gas-carrying component that may be removed in servicing. The application of thread-forming screws shall be limited to malleable materials. The application shall not result in deformation or cracking of the component. 2.2.15 Application of lubricant or sealant Valves with a rated working pressure exceeding 14 kPa, which require the addition of lubricant or sealant to maintain gas tightness, shall be capable of having this added without dismantling the valve. 2.2.16 Adjustments by the user The tightening of a gland or any other adjustment shall not permanently affect the ability of the valve to meet the performance requirements of this Standard.