AS NZS 3509:2009 pdf free download – LP Gas fuel vessels for automotive use
Threads shall be clean cut, even, without checks and cut to gauge. Threads and thread lengths for threaded connections shall be American National Gas Taper (NGT) in accordance with ANSI/CGA V-1. The diameter of an opening in an end shall not exceed 50% of the outside diameter of the vessel. The edge of any reinforced opening, or the edge of any reinforcement or welding thereto, shall be not closer to the outside circumference of the end than 10% of the outside diameter of the vessel, measured perpendicularly to the axis of the end. The height of branches, bosses, adaptors, or similar pressure-retaining parts shall be not greater than 25 mm, measured radially from the external profile of the shell to the highest point of the part, as shown in Figures 2.5 and 2.6.
2.1.6.1 General
Attachments shall be provided as required in accordance with AS/NZS 1425. Attachments shall be clear of longitudinal and circumferential joints and shall not prevent inspection of a pressure-retaining joint. Intermittent contact between an attachment and the vessel is permitted, i.e. by scalloped contact or attachment by ears, except where leak containment is a function of the joint. Non-pressure-retaining joints for joining of attachments directly to a pressure-retaining part shall be made by arc welding. Joints shall be designed to prevent crevice corrosion, and shall be continuously welded at all points of contact with a pressure-retaining part. Nameplates and doubling pads shall comply with Clause 2.1.6.6. NOTE: AS/NZS 1425 specifies the requirements for protection of the valves and connections, and for provision of leak containment from fittings, depending on the fuel vessel installation.
2.1.6.2 Valve-protecting attachments
There shall be provision for valve protection, either by a permanently attached valve guard or permanent attachments to which the valve protection is to be affixed. The throat thickness of welds for the provision of valve protection shall be not greater than the shell thickness.
Each vessel shall incorporate physical protection for its attached components. The protection provision shall be attached to the vessel in such a manner as would require the use of cutting implements or a unique tool for its removal, and shall be capable of withstanding, without permanent deformation, a static load of 150 kg applied from any direction to any position on the guard through a 75 mm square applicator plate. The protection guard shall be arranged so that no component will project beyond it (piping through the guard excepted). Attachments to the vessel shall be tested by bending back by hammer blows, until they lie against the vessel surface. Any tearing or cracking of the pressure-retaining portion shall be cause for rejection of the design or process. Any valve guard shall be of such dimensions as will ensure that the valve(s) fitted to the vessel lie wholly within the guard.