AS 2671 pdf download

AS 2671 pdf download.Hydraulic fluid power — General rules and safety requirements for systems and their components (ISO 4413:2010, MOD)
1  Scope
This International Standard specifies general rules and safety requirements for hydraulic fluid power systems and components used on machinery as defined by ISO 12100:2010, 3.1. It deals with all significant hazards associated with hydraulic fluid power systems and specifies the principles to apply in order to avoid those hazards when the systems are put to their intended use. NOTE 1  See Clause 4 and Annex A. The significant hazard noise is incompletely dealt with in this International Standard. NOTE 2  Noise emission depends especially on the installation of hydraulic components or systems into machinery. This International Standard applies to the design, construction and modification of systems and their components, also taking into account the following aspects: a) assembly; b) installation; c) adjustment; d) uninterrupted system operation; e) ease and economy of maintenance and cleaning; f) reliable operation in all intended uses; g) energy efficiency; and h) environment.
5  General rules and safety requirements
5.1  General 5.1.1 When designing hydraulic systems for machinery, all intended operations and use of systems shall be considered. Risk assessment, e.g. in accordance with ISO 14121-1, shall be carried out to determine the foreseeable risks associated with systems when they are used as intended. Reasonably foreseeable misuse shall not cause hazards. The risks identified shall be eliminated by design and, where this is not practicable, safeguards (first preference) or warnings (second preference) against such risks shall be incorporated, in accordance with the hierarchy established in ISO 12100. NOTE  This International Standard provides requirements for components of fluid power systems; some of these requirements are dependent on the hazards associated with the machine in which the system is installed. Therefore, the final specification and construction of the hydraulic system could need to be based on risk assessment and agreement between purchaser and supplier. 5.1.2 The control systems shall be designed in accordance with the risk assessment. This requirement is met when ISO 13849-1 is used. 5.1.3 The prevention of damage to the machine, system and the environment shall be considered. 5.2  Basic requirements for the design and specification of hydraulic systems 5.2.1  Selection of components and piping 5.2.1.1 All components and piping in the system shall be selected or specified to provide for safety in use, and they shall operate within their rated limits when the system is put to its intended use. Components and piping shall be selected or specified so as to ensure that they can operate reliably under all intended uses of the system. Particular attention shall be paid to the reliability of components and piping that can cause a hazard in the event of their failure or malfunction. 5.2.1.2 Components and piping shall be selected, applied and installed in accordance with the supplier’s instructions and recommendations, unless testing or field experience validates other components, applications or installations. Operator manuals for mobile machinery may exclude operation in certain situations. 5.2.1.3 It is recommended that, wherever practicable, components and piping made in conformance with recognized International Standards be used.5.2.2  Unintended pressures 5.2.2.1 All related parts of the system shall be designed or otherwise protected against foreseeable pressures exceeding the maximum working pressure of a system or the rated pressure of any part of the system if the excessive pressure can cause a hazard. Any system or part of a system that can be disconnected and sealed so that trapped fluid can be subject to a pressure increase or decrease (e.g. due to the change in a load or the fluid temperature) shall include means for limiting the pressure if the change can cause a hazard. 5.2.2.2 The preferred means of protection against excessive pressure is one or more pressure-relief valves located to limit the pressure in all related parts of the system. Other means, such as pressure- compensator pump controls, may be used to limit main system operating pressure, provided these means ensure safety under all operating conditions. 5.2.2.3 Systems shall be designed, constructed and adjusted to limit pressure surges and fluctuations. Pressure surges and fluctuations shall not cause hazards. 5.2.2.4 Loss of pressure or pressure drop shall not expose persons to a hazard and should not damage the machinery. 5.2.2.5 Means shall be provided to prevent unacceptable pressure build-up where high external loads are reflected on actuators.