RIGGING BLOCKS & SHEAVES
ASC provides the largest selection and most available inventory in rigging blocks that are used for both vertical and horizontal load movement. Block types include tackle, utility, rolling, and snatch blocks. Load fittings vary from hooks, eyes, swivels, yokes, bails, shackle and pins. ASC supplies and distributes lift assistance products from some of the very best quality components and ASC sheaves are made from the highest quality materials. ASC provides the best in manufacturing and materials meeting the ASME requirements:
ASME B30.26-5.1.2 Materials
- The rigging block shall have sufficient ductility to permanently deform before losing the ability to support the load at the temperatures that the manufacturer has specified for use.
- The shell or side plates shall be metal, wood, or synthetic.
- The sheave(s) shall be metal or synthetic.
- The load bearing straps and fitting(s) shall be made of metal.
The blocks rated load is the maximum load applied to the primary load fitting, not the line pull. Knowing the line pull, parts of line and block loading angles are required to determine the actual load applied to the block. ASC meets or exceeds the ASME requirements:
SECTION 26-5.3: RATED LOADS
Rated load shall be in accordance with the recommendation of the rigging block manufacturer. The terms “rated capacity” and “working load limit” are commonly used to describe rated load.
The number of sheaves is determined by the number of sheaves in the boom point of the crane. Blocks are designed to utilize all sheaves to attain the full working load limit. If the number of sheaves used (Reeved) is less, the allowable load on the block must be proportionally reduced. This must be done regardless of wire rope capacity. e.g. In z 30-Ton block, if 50% of the sheaves are used, the block working load limit must be adjusted down to 15 Tons.
Identification is a requirement and each new block shall be marked by the manufacturer:
Each new rigging block shall be marked by the manufacturer to show:
- name or trademark of manufacturer
- rated load
- rope size(s)
26-5.5.2 Maintenance of Identification
Rigging block identification should be maintained by the user so as to be legible throughout the life of the block.
ASC will provides the necessary training:
SECTION 26-5.7: TRAINING
Rigging block users shall be trained in the selection, inspection, cautions to personnel, effects of environment, and rigging practices.
ASC provides the inspection necessary to assure your organization of safe and long life use of your blocks:
Sheaves: When fewer sheaves are used it is also very important to symmetrically reeve the sheaves.
SECTION 26-5.8: INSPECTION, REPAIR, AND REMOVAL
26-5.8.1 Initial Inspection
Prior to use, all new, altered, modified, or repaired rigging blocks shall be inspected by a designated person to verify compliance with the applicable provisions of the standard. Written records are not required.
26-5.8.2 Frequent Inspection
- A visual inspection shall be performed by the user or other designated person each shift before the rigging block is used. Semi-permanent and inaccessible locations where frequent inspections are not feasible shall have periodic inspections performed.
- Conditions such as those listed in para. 26-5.8.4, or any other condition that may result in a hazard, shall cause the rigging block to be removed from service. Rigging blocks shall not be returned to service until approved by a qualified person.
- Written records are not required.
26-5.8.3 Periodic Inspection
- A complete inspection of the rigging block shall be performed by a designated person. The hardware shall be examined for conditions such as those listed in para. 26-5.8.4 and a determination made as to whether they constitute a hazard.
- Periodic Inspection Frequency. Periodic inspection intervals shall not exceed one year. The frequency of periodic inspections should be based on:
- frequency of use
- severity of service conditions
- nature of lifts being made
- experience gained on the service life of hardware used in similar circumstances
- Guidelines for the time intervals are
- normal service – yearly
- severe service – monthly to quarterly
- special service – as recommended by a qualified person
- Written records are not required.
26-5.8.4 Removal Criteria
Rigging blocks shall be removed from service if conditions such as the following are present and shall only be returned to service when approved by a qualified person:
- missing or illegible identification
- misalignment or wobble in sheaves
- excessive sheave groove corrugation or wear
- loose or missing nuts, bolts, cotter pins, snap rings, or other fasteners and retaining devices
- indications of heat damage, including weld spatter or arc strikes
- excessive pitting or corrosion
- bent, cracked, twisted, distorted, stretched, elongated, or broken load bearing components
- excessive wear, nicks, or gouges
- a 10% reduction of the original or catalog dimension at any point
- excessive damage to load bearing threads
- evidence of unauthorized welding or modifications
- for hooks, the removal criteria specified in B30.10
- for shackles, the removal criteria specified in B30.26
- other conditions, including visible damage that cause doubt as to the continued use of the rigging block