ASME B30.7-2006 pdf download

ASME B30.7-2006 pdf download.Base-Mounted Drum Hoists.
(e) Swinger brakes shall have holding power in both directions to prevent movement of the rotating member of the load-handling equipment. The brake shall be capable of being set in the holding position and remaining so without attention on the part of the operator.
‘f,) A power control braking means (such as regenerative, dynamic, countertorque braking, or power controlled lowering) or a mechanically controlled braking means shall be provided and shall be capable of maintaining controlled lowering speeds.
7-1.2.4 Adjustments
Brakes and clutches shall be provided with adjustments where necessary to compensate for wear and to maintain tension in springs where used.
7-1.2.5 Guards
(a) Exposed moving parts (such as gears, set screws, projecting keys, chains, chain sprockets, and reciprocating or rotating parts), which might constitute a hazard under normal operating conditions, shall be guarded.
(b) Guards shall be fastened.
(c) Guards shall be capable of supporting, without permanent distortion, the weight of a 200 lb (90 kg) person unless the guard is located where it is unlikely that a person viIl step on it.
7-1.2.6 Ropes
(a) Ropes shall be of a size, grade, and construction to withstand the loads imposed. Fiber ropes may be used only with the manufacturer’s or qualified person’s recommendations.
(b) Ropes shall be of a length for the entire range of movement specified for the application, with no less than two full wraps of rope on the drum at all times.
(c) The design factor for ropes, except rotation resistant ropes, shall be not less than 3.5. The design factor for rotation resistant ropes shall be not less than 5. IThe design factor of 5 or greater for rotation resistant ropes may he modified by the hoist user by complying with the provisions of para. 7-3.2.1(b).j
NOTE: ASME B30.6 requires a minimum design factor of 3.5:1 for running ropes used with derricks. ANSI A 10.5 requires a minimum design factor for ropes of 7:1.
(d) Wherever exposed to temperatures in excess of 180°F (82°C), rope having an independent wire rope or wire strand core, or other temperature damage-resistant core shall be used.
(e) The rope (right or left lay) should be selected in accordance with the drum rotation and anchorage.
7-1.2.7 Controls
(a) All controls used during the normal operating cycle shall be located within reach of the operator while at the operator’s station. Arrangement of controls should be in accordance with applicable requirements of
SAE J983.
(1) Electric motor operated hoists shall be provided with a device that will disconnect all motors from the line on failure of power, and will not permit any motor to be restarted until the controller handle is brought to the off position, or a reset switch or button is operated.
(c) Electric motor operated hoists that are capable of overspeeding the power plant on overhauling regenerative loads shall be provided with means to prevent such overspeed ing.
(LI) Remote operated base-mounted drum hoists shall function so that if the control signal for any hoist motion becomes ineffective, that hoist motion shall stop.
7-1.2.8 Prime Mover Controls
Controls for operating the prime mover shall be within reach of the operator and shall include means to
(a) start and stop
(b) control speed of internal combustion engines or drive motors
(c) stop two-cycle internal combustion engines or drive motors under emergency conditions
(d) shift selective transmissions when used
7-1.2.9 Control Forces and Movements
When a hoist is operated within the manufacturer’s ratings, the following shall apply under normal operation.
(a) Forces not greater than 35 lb (156 N) on hand levers. Forces not greater than 50 lb (222 N) or less than 8 lb (36 N) on foot pedals.
(b) Travel distance on hand levers not greater than
14 in. (356 mm) from neutral position on two-way levers,
and not greater than 24 in. (610 mm) on one-way levers.
Travel distance on foot pedals not greater than 10 in.
(254 mm).
7-1.2.10 Engine Clutch
All hoists except direct geared hoists shall be provided with a clutch for disengaging power to the machinery. The clutch control shall be within reach of the operator’s station.
7-1.2.11 Electric Resistors
(a) Resistor units shall be supported to minimize vibration effect.
(b) Provision shall he made to prevent broken parts or molten metal from falling from the hoist.
(c) If ventilated or nonventilated resistor enclosures.