ASME B30.28:2015 pdf download

ASME B30.28:2015 pdf download.Balance Lifting Units
Volume B30.28 includes provisions that apply to the marking, construction, installation, inspection, testing, maintenance, and operation of balance lifting units (bal- ancers). Balancers are distinguished by their ability to float the load. This Volume applies to balancers with fixed arm support (Fig. 28-0.1-1) and balancers with overhead flexible lifting medium (Fig. 28-0.1-2). This Volume does not apply to balancers with autonomous operation or balancers used for lifting personnel, as these units require additional considerations, provi- sions, and features that are not included in this Volume.
abnormal operating conditions: environmental conditions that are unfavorable, harmful, or detrimental to or for the operation of balancers, such as excessively high or low ambienttemperatures, exposure to adverse weather, corrosive fumes, dust-laden or moisture-laden atmo- spheres, and hazardous locations. balancer: a balance lifting unit capable of moving loads within the rated capacity and with the capability to float the load. balancer service, heavy: service that involves operation within the rated load limit, which exceeds normal service. balancer service, normal: service that involves operation with loads at or less than 65% of rated load for not more than 50% of the time. balancer service, severe: service that involves normal or heavy service with abnormal operating conditions. balancer, standby: balancers that are not in regular service but are used occasionally or intermittently, as required. clearance: the distance from any part of the balancer to the nearest obstruction. end effector: a feature, device, method, or components for connectingthe load to a balancer. Also maybe referred to as “receiver” or “below the hook lifting devices” (see ASME B30.20).exposed: applies to hazardous objects not guarded or isolated (capable of being contacted inadvertently). float the load: the ability to move the load up or down, without inputs to the operational controls, by applying a force to the load of less than 5% of the load. hazardous (classified) locations: locations where fire or explosion hazards may exist. Locations are classified depending on the properties of the flammable vapors, liquids, or gases, or combustible dusts or fibers that may be present and the likelihood that a flammable or combustible concentration or quantity is present. Refer to NFPA 70. Class I locations: locations in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures. Class II locations: locations that are hazardous because of the presence of combustible dust. Class IIIlocations: locations that are hazardous because of the presence of easily ignitable fibers or flyings, but in which such fibers or flyings are not likely to be in suspension in the air in quantities sufficient to produce ignitable mixtures. lifting medium: the balancer component that supports and moves the load up and down and determines the type of balancer. load: the total superimposed weight on the balancer including any end effector devices attached to the balancer. load, rated: the maximum load designated by the manu- facturer for which the balancer is designed and built. manual valves: a valve for which a manual actuator is the only means of valve actuation.normal operating conditions: conditions during which bal- ancers are performing functions within the scope of the original design. overload: any load greater than the rated load. qualified person: a person who, by possession of a recog- nized degree or certificate of professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve or resolveproblems relatingto the subjectmatterandwork. rope: refers to wire rope unless otherwise specified. safety device: a feature placed in use for the specific pur- pose of preventing an unsafe condition and designated as such by the manufacturer. shall: a word indicating a requirement. sheave: a grooved wheel or pulley used with a rope to change the direction and point of application of a pulling force. should: a word indicating a recommendation. stop: a device to limit travel. This device is normally attached to a fixed structure and does not have energy- absorbing ability. switch: a device for making, breaking, or changing the connections in an electric, hydraulic, or pneumatic circuit.