Posted by Melissa Hall in #YHSafetyTips, Mar 06, 2019
Did you know the American Society of Mechanical Engineers (ASME) updated their standards that apply to below-the-hook lifting devices in 2018? Often referred to as a lifter, a below-the-hook lifting device attaches a load to a hoist. BTH devices come in several forms including: structural & mechanical lifting devices, vacuum lifting devices, close proximity operated lifting magnets, remotely operated lifting magnets, scrap & material handling grapples, and clamps. ASME BTH-1 and ASME B30.20-18 are the most important standards for the design and marking of below-the-hook lifting devices.
ASME B30.20-18 provides detailed standards on the classification, marketing, construction, installation, inspection testing, maintenance, and operation of below-the-hook lifting devices. ASME BTH-1 provides detailed information on the design criteria of below-the-hook lifting devices.
BTH Markings & ID Tags
All BTH devices must include rated load markings that are marked legibly on the device or on a tag that is attached to the device. If the BTH device is made up of several lifters that are detachable from the group, each individual lifter needs to be marked with the individual rated loads.
All BTH devices also need an ID tag, which is a nameplate or other permanent marking that is affixed to the structural or mechanical lifter. ID tags should list the following:
ASME BTH-1 divides lifting devices into two design categories, A & B.
Design Category A
Design category A states “Design Category A should be designated when the magnitude and variation of loads applied to the lifter are predictable, and where the loading and environmental conditions are accurately defined or not severe.”
Lifting devices in design category A are limited to a Service Class of 0, which limits the device’s load cycles to a maximum of 20,000 cycles. Design category A lifters are often found in rapid manufacturing locations where an identical load is used and where there are no outside conditions acting on the load.
Design Category B
The most common design category with most qualifying below-the-hook lifting devices, this category should be designated “when the magnitude and variation of loads applied to the lifter are not predictable, and where loading and environmental conditions are severe or not accurately defined.” Lifting devices under this design category can fall under service class 0-4 and require a design factor of 3:1.
ASME BTH-1 Table C2-1 Service Class
|Service Class||Load Cycles|
ASME BTH-1 Table C2-1 Service Class Life (Desired Life in Years)
|Cycles Per Day||1||5||10||20||30|
Operational Practices for Lifting Devices
Below-the-hook lifting devices shall only be operated by the following qualified personnel:
Below-the-hook lifting devices shall not:
Inspections of Below-the-Hook Devices
All BTH devices should be inspected before and during each lift made by the lifter. In addition to inspections during use, visual inspections by a qualified person should be performed on a frequent and periodic basis. The frequency of these inspections varies based on the level of service that is needed for the BTH device.
Frequent inspections are defined as visual examinations by the operator or other designated person. Records are not required for frequent inspections.
A visual inspection is performed by a qualified inspector who records the current condition of the below-the-hook lifter in order to provide the basis for a continuing program of recorded evaluation. Dated reports for periodic inspections shall be maintained.
All YorkHoist inspectors meet and exceed OSHA, ANSI, CMMA, and CCAA requirements.
All welding done during the construction of the lifting device must be done in accordance with ASME BTH-1 and ANSI/AWS D14.1.
For more information or to purchase a copy of the standard, visit ASME website, www.ASME.org.
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