ASME B30-20 pdf download

ASME B30-20 pdf download Below-the-Hook Lifting Devices Safety Standard for Cableways, Cranes, Derricks, Hoists, Hooks, Jacks, and Slings
lifting beam (spreader beam): a load-supporting lifter [seeFig. 5, sketch (a)].
lock bar sheet lifter: a supporting lifter [see Fig. 5,sketch (j)].
manipulating lifter: a lifter that rotates the load about oneor more axes during the lifting process (see Fig. 4).mechanical lifting device: a mechanism composed of twoor more rigid parts which move with respect to eachother for attaching a load to a hoisting device.
service,heavy: that service which involves operationwithin the rated load limit that exceeds normal service.service, normal: that distributed service which involvesoperation with various weights within the rated loadlimit, or uniform loads less than 65% of rated load.
service, severe: that service which involves normal orheavy service with abnormal operating conditions.
structural lifting device: a lifter consisting of an assemblyof rigid parts designed to hold and attach a load to ahoisting device.
supporting lifter: a lifter that carries the load on rigidprojection(s) or bearing surface(s) (see Fig. 5).
SECTION 20-0.4:DEFINITIONS FOR CHAPTER 20-2breakaway force: the external force that is required toseparate the vacuum pad or vacuum lifting device fromthe load when applied perpendicular to the attachmentsurface.
four-pad powered vacuum lifter: see Fig. 6, sketch (d).four-pad poered vacunm lifter manipulator: see Fig. 6,sketch (e).
high-femperature surface: a condition where the surfaceto which the vacuum pad (or pads) is attached is above250°F(120°C).
horizontal lift: a condition where the surface to whichthe vacuum pad (or pads) is attached is in a horizontalplane.
low-temperature seroice: a condition where the surface towhich the vacuum pad (or pads) is attached is below0°F(-18°C).
multiple-pad mechanical vacuum lifter: see Fig.6, sketch (c).nonporous material: a material that is not permeable byfluid.
peel off: a prying action that takes place when deflectionof an overhanging load exceeds the compensating ability of the vacuum pad or vacuum lifting device, resultingin loss of load.
porous material: a material that is permeable by fluid.sealing ring: that part of the vacuum pad which formsthe seal of the vacuum chamber between the vacuumpad body or vacuum lifting device and the attachedmaterial.
serzvice, heavy: that service which involves operationwithin the rated load limit that exceeds normal service.service, normal: that distributed service which involvesoperation with various weights within the rated loadlimit, or uniform loads less than 65%of rated load.service, severe: that service which involves normal orheavy service with abnormal operating conditions.shear breakazoay force: the external force that is requiredto separate or slide the vacuum pad or vacuum liftingdevice on the load when the force is applied parallel tothe attached load surface.
single-pad mechanical oacuum lifter: see Fig. 6, sketch (b).trvo-pad mechanical zacxun lifter: see Fig. 6, sketch (a).vacu 1M: pressure less than ambient atmosphericpressure.
zacunr lifter: a below-the-hook lifting device for liftingand transporting loads in a fixed attitude using a holdingforce by means of vacuum (see Fig.6).
zacuxu111 manxipulafor: a vacuum lifter capable of reposi-tioning the load while suspended.
zacuaumr pad: a device that applies a holding force on theload by means of vacuum.
zacni reserzoir: the evacuated portion of the vacuumsystem whose function is to compensate for leakage intothe vacuum system or to provide a vacuum reserve inthe event of vacuum generator failure.
zertical lift: a condition where the surface to which avacuum pad is attached is in a vertical plane.
SECTION 20-0.5:DEFINITIONS FOR CHAPTER 20-3battery systemr (backup): batteries used to guard againstinadvertent load release due to the loss of primary powerto the magnet system.
cold current: that current drawn by the lifting magnetwhen its coil is at 68°F (20°C) and at rated voltage.