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1. Determine weight of the load.
2. Select sling having suitable characteristics for the type of load, hitch and environment.
3. Slings shall not be loaded in excess of the rated capacity. Consideration should be given to the angle from the vertical (sling-to-load angle) which affect rated capacity. (See sling chart on pages 22 & 23.)
4. Slings with fittings which are used in a choker hitch shall be of sufficient length to assure that the choking action is on the webbing.
5. Slings used in a basket hitch shall have the load balanced to prevent slippage.
6. Slings shall not be dragged on the floor or over an abrasive surface.
7. Slings shall not be twisted or tied into knots, or joined by knotting.
8. Slings shall not be pulled from under loads when the load is resting on the sling.
9. Slings shall always be protected from being cut by corners, sharp edges, protrusions or abrasive surfaces.
10. Do not drop slings equipped with metal fittings.
11. The opening in fittings shall be the proper shape and size to insure that the fitting will seat properly in the hook or other attachments.
ENVIRONMENTAL CONSIDERATIONS
1. Slings should be stored in a cool, dry, dark place and should not be exposed to sunlight to prevent mechanical or chemical damage,when not in use.
2. Chemically active environments can affect the strength of syntheticweb slings in varying degrees ranging from none to total degradation. The sling manufacturer should be consulted before slings are used in chemically active environments.
ACIDS
1. Nylon is subject to degradation in acids, ranging from none to total degradation.
2. Polyester is resistant to many acids but is subject to degradation ranging from none to moderate in some acids.
3. Each application shall be evaluated, taking into consideration the following:
A. Type of Acid C. Concentration
B. Exposure conditions D. Temperature
ALKALIS
1. Polyester is subject to degradation in alkalis, ranging from none to total degradation.
2. Nylon is resistant to many alkalis but is subject to degradation ranging from none to moderate in some alkalis.
3. Each application shall be evaluated, taking into consideration the following:
A. Type of Alkali C. Concentration
B. Exposure conditions D. Temperature
Nylon and polyester slings shall not be used at temperatures in excess of 180º F. (82º C.).
Slings incorporating aluminum fittings shall not be used where fumes, vapors, sprays, mists or liquids of alkalis and/or acids are present. Environments in which synthetic webbing slings are continuously exposed to ultraviolet light can affect the strength of synthetic webbing slings in varying degrees ranging from slight to total degradation.
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A. Factors which can determine the degree of strength loss are:
1. Length of time of continuous exposure.
2. Sling construction and design.
3. Other environmental factors such as weather conditions and geographic location.
B. Suggested procedures to minimize the effects of ultraviolet light:
1. Store slings in a cool, dry, dark place when not being used for prolonged periods of time.
2. Inspect slings weekly or more often, depending on frequency of sling use.
C. Visual indications of ultraviolet degradation are:
1. Bleaching-out of sling color.
2. Increased stiffness of sling material.
3. Surface abrasion in areas not normally in contact with the load.
D. Proof-Testing: Slings used in environments where they are subject to continuous exposure to ultraviolet light should be proof-tested to two times rated capacity annually, or more frequently depending on severity of exposure.
INSPECTION
TYPE OF INSPECTION
A. Initial Inspection: Before any new or repaired sling is placed in service, it shall be inspected to insure that the correct sling is being used as well as to determine that the sling meets the require-ments of this specification.
B. Frequent Inspection: This inspection should be made by the person handling the sling each time the sling is used.
C. Periodic Inspection: This inspection shall be conducted by designated personnel. Frequency of inspection should be based on:
1. Frequency of sling use.
2. Severity of service conditions.
3. Experience gained on the service life of slings used in similar applications.
4. Periodic inspections should be conducted at least annually.
POSSIBLE DEFECTS
A sling shall be removed from service if any defects such as the following are visible:
A. Acid or alkali burns.
B. Melting, charring or weld spatter of any part of the sling.
C. Holes, tears, cuts, snags or embedded particles.
D. Broken or worn stitching in load-bearing splices.
E. Excessive abrasive wear.
F. Knots in any part of the sling.
G. Distorted, excessively pitted, corroded, or broken fittings.
H. Other defects which cause doubt as to the strength of the sling.
INSPECTION RECORDS
Written inspection records, utilizing the identification for each sling as established by the user, should be kept on file for all slings. These records should show a description of the new sling and its condition on each subsequent inspection.
REPAIR OF WEB SLINGS
Slings shall be repaired only by a sling manufacturer. When repaired by other than the original manufacturer, the sling shall be permanently marked to identify the repair agent. All repaired slings shall be proof tested to two (2) times its newly assigned rated capacity before being put back into service. Certification of proof test should be provided. Temporary repairs of either Webbing, fittings or stitching shall not be permitted.
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