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ASME HST-2-2018 pdf free

ASME HST-2-2018 pdf free.Performance Standard for Hand Chain Manually Operated Chain Hoists.
2-1.5.2 Hand Chain Putt (Geared TroLLey)
The hand-chain-operated type is recommended where trolley motion is relatively infrequent or short, and for those loads and beam heights where a plain-type trolley would be Impractical. The hand-chain-operated trolley provides good load spotting ability.
The trolley hand chain shall be guarded to prevent hand chain disengagement from the hand chain wheel, The trolley hand chain shall withstand, without permanent distortion, a pull of 3 times the pull required to traverse the trolley with rated load.
The trolley motion is obtained by pulling on the hand chain, which rotates a hand chain wheel, which in turn is directly connected to the trolley wheels through gears or sprockets. Hand-chain-operated trolleys are recommended for
(a) capacities over 3 tons (3000 kg)
(b) beam elevations greater than 20 ft (6 m) above operator’s floor level
(c) accurate load spotting ability
An overload limiting device, when furnished, shall be designed to permit operation of the hoist within its rated load and to limit the amount of overload that can be lifted by a properly maintained hoist under normal operating conditions The overload limiting device may allow the lifting of an overload, but shall be designed to prevent the lifting of an overload that could cause damage to the hoist. This does not imply that any overload is to be intentionally applied to the hoist.
The overload limiting device is an emergency device and shall not be used to measure the maximum load to be lifted. and shall not be used to sense the overload imposed by a constrained load.
(a) Load sprockets shall have pockets formed to allow proper engagement of the load chain.
(b) Load sprockets shall be guarded to minimize entrance of Foreign objects.
(c) Provision shall be made to guard against jamming of the load chain with the hoist mechanism under normal operating conditions.
The hoist shall lift or lower the rated load in a controlled manner when a manual force is applied to the hand chain. When equipped with more than one hand chain, the hand chain pull indicates the required pull for each hand chain.
(a) Load chain shall be suitable for hoist service. Chain shall be accurately pitched to pass over sprockets without binding.
(b) Load chains shall be proof tested by the chain manufacturer or hoist manufacturer with a load at least equivalent to 1/2 times the hoist rated load divided by the number of chain parts (lines) supporting the load.
Ic) If a load is supported by more than one part (line) of load chain, the tension on the parts (lines) shall be equalized.
Hooks shall follow the guidance of ASME U30.1O.
(a) If the hooks are of the swiveling type. they should be free to rotate. Load hooks should be capable of rotating through 360 deg when supporting the rated load.
(b) Hooks shall incorporate latches unless the application makes the use of the latch impractical. When required, a latch shall be provided to bridge the opening of the hook for the purpose of retaining slings, chains, etc.. under slack conditions.ASME HST-2 pdf download.

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