Views:87 Author:DINGSHENGFUTE Publish Time: 2019-05-20 Origin:Site
To move materials safely from one place to another is troublesome in some cases. Hoists are often used when materials are too heavy or bulky to be safely moved manually. Because hoists rely upon slings to hold their suspended loads, slings are the most commonly used materials-handling apparatus.
Slings, chokers, shackles and hoists are are available in many different materials and styles. Slings are commonly used in combination with a lifting device, such as an overhead crane, hoist, or forklift.
Wire Rope: The most commonly used sling. Used in the construction and other applications where heavy loads and rugged conditions exist.
Chain: Combines superior strength, ease of handling and durability. The combination of heavy loads, elevated working temperatures and severe lift conditions usually dictate that an alloy chain sling be used.
Mesh: Wire and Chain. Excellent in lifting objects that are hot or have sharp edges, such as bar stock or plate steel. Mesh slings usually have wide load bearing surfaces that greatly enhance load balancing. Machine shops and steel warehouses typically have applications requiring mesh slings.
Synthetic: Both web and round-slings are used where loads must be protected from damage. Their light weight and flexibility reduce fatigue and strain on the rigger.
The sections below serve as a guideline when hoisting or rigging at Princeton University.
The following basic guidelines must be followed for all types of rigging:
(1) It is essential to determine the proper style, size, length, diameter and thickness of sling needed for the application prior to use. Select the sling best suited for the job.
(2)Never tie knots in slings.
(3)Rigging equipment must not be loaded in excess of its safe working load.
(4)Hooks must be provided with safety latches.
(5)Know the limitations of the lifting device
(6)Determine the center of gravity of the load.
(7)Protect sling from sharp surfaces.
(8)Protect load from rigging, if necessary.
(9)Allow for increased tension caused by sling angles.
(10)Equalize load on multiple leg slings.
(11)Maintain load control. If required, attach tag lines prior to lift.
(12)Keep personnel clear of lift area.
(13)Lift load a few inches and check rigging.
(14)Start and stop the lift slowly.
(15)Watch for obstructions and power lines. Maintain at least 10 feet from energized power lines at all times.
(16)Use proper hand signals when communicating with crane operators.