ASME HST-6:2015 pdf free download

ASME HST-6:2015 pdf free download Performance Standard for Air Wire Rope Hoists
SECTION 6-2.1 ROPE SHEAVES
(a) The pitch diameter of running sheaves should notbe less than 16 times the rope diameter.
(b) The pitch diameter of nonrunning sheaves shouldnot be less than 12 times the rope diameter.
SECTION 6-2.2DRUM
(a)The pitch diameter of the drum should not be lessthan 18 times the diameter of the rope used.
(b)No less than two wraps of rope shall remain oneach anchorage of the hoist drum when the hook is atits lower limit of travel as determined by rated lift, unlessa lower limit device is provided, in which case no lessthan one wrap shall remain on each anchorage of thehoist drum.
SECTION 6-2.3 REEVING
Hoist reeving may be either single or double, and maybe one part or multiple part.
6-2.3.1 Single Reeving
On single-reeved hoists, one end of the rope isattached to the drum. Continuous drum grooving runsin one direction. The load block moves laterally in thedirection of the axis of the drum as the rope winds ontoor off of the drum.[See Fig.6-0.2-2, illustration (a).]
6-2.3.2 Double Reeving
On double-reeved hoists, both ends of the rope areattached to the drum. The drum is grooved with left-and right-hand grooves beginning at both ends of thedrum, then grooving toward the center of the drum. Theload block follows a true vertical lift (true vertical path)as the ropes wind toward or away from each other ontoor off of the drum. [See Fig. 6-0.2-2, illustration (b).]
SECTION 6-2.4OVERLOAD LIMIT DEVICE
(a) An overload limit device, when furnished, shallbe designed to permit operation of the hoist within itsrated load and to limit the amount of overload that can be lifted by a properly maintained hoist, under normaloperating conditions.
(b) The overload limit device may allow the lifting ofan overload but shall be designed to prevent the liftingof an overload that could cause damage to a hoist, trolley,or supports.This does not imply that any overload isto be intentionally applied to the hoist.
(c)The overload limit device is an emergency device.lt shall not be used to measure the maximum load tobe lifted and shall not be used to sense the overloadimposed by a constrained load.
SECTION 6-2.5 CONTROL
Hoists and trolleys shall have pendant, pull cord, orrod control.Control actuators shall spring return to the“OFF”position.
6-2.5.1 Pendant Control
(a)The pendant control station shall be supported toprotect the pneumatic hoses against strain.
(b)The pendant control station shall be clearlymarked to indicate the function of each actuator.
(c) Unless otherwise specified, the standard pendantcontrol shall have a length that will locate the pendantapproximately 3 ft to 5 ft (o.9 m to 1.5 m) above thelower limit of lift.
6-2.5.2 Pull Control
Pull control shall consist of two pull chains or cordswith suitable handle(s) clearly marked for direction.Unless otherwise specified,the standard pull controlshall have a length that will locate the control handlesapproximately 3 ft to 5 ft (0.9 m to 1.5 m) above thelower limit of the lift.
6-2.5.3 Rod Control
Rod control shall permit control of hoist or trolleymotion by linear or rotary movement of the rod handle,or a combination of both. The rod handle shall be clearlymarked for direction of motion. Unless otherwise speci-fied, the rod handle shall be located 3 ft to 5 ft (0.9 mto 1.5 m) above the lower limit of lift.