ASME HST-4 pdf download.Performance Standard for Overhead Electric Wire Rope Hoists.
(a) ASME HST-4 establishes performance requirements for electric wire rope hoists for vertical lifting service involving material handling of freely suspended (unguided) loads using wire rope with one of the following types of suspension:
(1) lug
(2) hook
(3) trolley
(4) base or deck mounted (does not include base-mounted winches of the type covered by ASME 1330.7)
(5) wall or ceiling mounted (does not include base-mounted winches of the type covered by ASME 1330.7)
(b) This Standard is applicable to hoists manufactured after the date on which this Standard Is issued. This Standard Is not applicable to
(1) damaged or malfunctioning hoists
(2) hoIsts that have been misused or abused
(3) hoists that have been altered without authorization of the manufacturer or a qualified person
(4) hoists used for the purpose of lifting or lowering people
(5) hoists used for the purpose of drawing both the load and the hoist up or down the hoist’s own wire rope
(6) hoists used for marine and other applications as required by the U.S. Department of Defense (DOD) unless Nonmandatory Appendix A is invoked
(c) The requirements of this Standard shall be applied together with the requirements of ASME B30.16. Please also refer to ASME 1330.16 for requirements pertaining to marking, construction, and installation; inspection, testing, and maintenance; and operation.
SECTION 4-0.2: DEFINITIONS
abnormal operating conditions: environmental conditions that are unfavorable, harmful, or detrimental to the operation of a hoist, such as excessively high or low ambient temperatures; exposure to weather, corrosive fumes, dust-laden or moisture-laden atmospheres; and hazardous locations.
ambient temperature: the temperature of the atmosphere surrounding the hoist.
base or deck mounted: a type of mounting where the hoist is mounted to the top side of a horizontal supporting surface. beam: an overhead standard structural or specially fabricated shape on which the trolley operates.
block load: the assembly of hook or shackle, swivel, bearing, pins, sheaves, and frame suspended by the rope. This shall include all appurtenances reeved into the hoisting rope.
brake: a device, other than a motor, used for retarding or stopping motion by friction or power means. brake, holding: a friction brake for a hoist that is automatically applied and prevents motion when power is off.
brake, mechanical load: an automatic type of friction brake used for controlling loads in a lowering direction. This unidirectional device requires torque from the motor to lower a load but does not impose additional load on the motor when lifting a load. A mechanical load brake may also be used as a holding brake if designed as such by the manufacturer.
braking, control: a method of controlling speed by removing energy from the moving body or by imparting energy in the opposite direction.
braking, countertorque (plugging): a method of controlling speed by applying a variable motor torque in the direction opposite to the direction that the motor is rotating as it is being overhauled by the load.
The hand chain shall be guarded to prevent its disengagement from the hand chain wheel. The hand chain shall withstand, without permanent deformation, a force of three times the pull required to traverse the trolley with rated load.
4-1.6.3 Motor Operated
A motor-operated trolley is recommended where the operating frequency, distance of travel, rated load, beam elevation, or type of load being handled exceeds recommendations for the use of plain or hand-chain-operated trolleys. The design of motor-operated trolleys shall be based on intermittent operation on a straight beam unless otherwise specified. Where trolley travel involves a curved beam, beam switches, exceptionally long runs, or near continuous operation, a special design may be required. Full particulars should be provided with the Inquiry.
A cushioned start or multispeed drive is recommended for trolley speeds above 100 It/mm (30 rn/mm) or for use on beams with curved sections. Brakes, when specified, should be actuated by mechanical or electrical means and shall have the following characteristics:
(a) Brakes shall have sufficient capacity to stop the trolley within a distance in feet (meters) equal to 10% of the rated speed in feet (meters) per minute when traveling at rated speed with rated load.
(b) Brakes shall have heat dissipation capability for the frequency of operation defined by the user.
(c) Brakes shall have provision for adjustment where necessary to compensate for wear.
4-1.6.4 TroLLey Wheels
When a trolley Is required for use with a hoist, the type and size of support beam must be specified to ensure the trolley wheel contour is suitable for the contour of the beam.
ASME HST-4 pdf download
