STRUCTURAL and MECHANICAL LIFTERS
BELOW-THE-HOOK LIFTING DEVICES
Lacking an OSHA standard, OSHA will generally rely on the methods and procedures determined by ANSI, ASME, other standards writing bodies, as well as the applicable industry.
The criteria listed below should be adhered to in order for a Structural / Mechanical Lifting Device (non-sling) to be manufactured and certified in accordance with ASME standard B30.20.
The use of Structural / Mechanical Lifting Devices, NOT manufactured in accordance with ASME B30.20, should an accident occur, could place the user and seller in a serious and potentially indefensible liability position.
Determine the maximum load the lifter will be used for; this is the rated load. The lifter must be designed with a minimum design factor of three (3) based on yield strength. ITNAC looks at a design factor of 5 based on ultimate strength. We compare the yield with the ultimate and uses the safer of the two values.
To support the rated load and its design factor, the supplier should be able to trace all material and component specifications and be able to recover any applicable material certifications.
All welding and welder certification must be in accordance with AWS D1.1.
Lifting devices should be load tested by the manufacturer, not to exceed 125% of rated load.
The rated load must be marked on the lifter where it is
clearly visible. A name plate or other permanent marking must be attached to the lifter
and include the following:
(A) MANUFACTURER NAME
(B) SERIAL NUMBER
(C) LIFTER WEIGHT
(D) RATED LOAD CAPACITY
The serial number provides the tracing mechanism for the criteria of the lifter.