Slings, their types, the grading of a sling, rope, chain, textile
Slings, norm rejection, types of rope, chain, textile slings.
Slings are fittings (steel cables, ropes, chains, tape), providing the lifting and moving of cargo or the girth of the object and secure its retention to ensure that a given position in space.
Rejection of slings, norm rejection
Slings are fittings (steel cables, ropes, chains, tape), providing the lifting and moving of cargo or the girth of the object and secure its retention to ensure that a given position in space. In climbing equipment is the constructive elements, allowing to fix and fix the safety rope. Regardless of the purpose of the articles, both ends of each of them are equipped with loops, rings, kosami, brackets, hooks and other devices that help in the operation.
The main task of the strop – a reliable fixation of the moved or transported object, ensuring its safety and security to others. They are widely used industrial and agricultural enterprises, gas, oil, forestry, construction and other industries. They are also essential when carrying out loading and unloading activities. Therefore, the products must be of high quality, durable, have good flexibility and high load-bearing capacity. She standartisied and subject to mandatory certification.
Slings belong to rigging equipment and are susceptible to gradual damage. Therefore, to extend the period of operation necessary to evenly distribute the load and monitor the emerging defects. They can have different terminations of the ends (zaplatka, pressure testing, etc.), different properties, device. It is important to use them as directed for the recommended types of cargo should not exceed the permissible parameters. Quality products always complies with GOST.
Also, each sling shall be accompanied by a tag number, which knocked out the following information: when and by whom it is made, the date and place of passing the test, what is the weight calculated. Permissible mass may be duplicated the colour of the product or its parts. But no labels is prohibited. Guided by applicable standards, today there are three main categories: slings. Given the material they may be:
Rejection of slings, norm rejection chain, rope, textile slings:
The rejection chain slings:
– missing (or corrupted) tag or a passport from a lanyard;
– missing or unreadable markings on the webbing elements;
– the difference between the lengths of the branches of the sling, if the free SAG is more than 15 mm;
– when the elongation of the link chain, link, hinged and suspensions of more than 5% of its original size;
– if you reduce the cross section diameter of the chain links and the chain links suspended due to wear more than 8%;
– on hooks or other gripping elements are missing safety locks.
Rejection rope slings:
– missing (or corrupted) tag or a passport from a lanyard;
– nodes, twists, kinks, and creases on the ropes;
– if the number of visible breaks of the outer wires of the rope exceeds (for slings of rope double lay) 3d – 4, 6d – 6, 30d – 16;
– reduction of rope diameter due to wear or corrosion 7% or more;
– decrease in diameter of the outer wires due to wear or corrosion by 40% or more;
– reduction of rope diameter by 10% due to damage to the core;
open at least one strand;
– the extrusion of the core;
– damage due to temperature or electric arc discharge;
– deformation Deadeye or wear it cross-section of more than 15%;
– cracks in the insulating sleeve or changing its size by more than 10% of the original;
– on hooks or other gripping elements do not exist safety locks;
– in the absence of or damage to the marking of the tag;
with corrupted or missing braids or other protective elements in the presence of the protruding ends of the wire at the point of zaplatki;
– with hooks that do not have safety locks.
The grading of textile slings:
– missing the mark (tag), or read details about sling;
nodes in carrier tape slings;
the transverse cuts or breaks in the tape;
longitudinal cuts or breaks in the tape, the total length of which exceeds 10% of the entire length of the tape sling or isolated breaks no longer than 50 mm;
– local bundles of strips of sling, except in places sealing the edges of the tape, for length, in the amount of more than 0.5 m on one extreme or two or more internal seams (when you break three or more stitches of the seam);
local delamination of the tape sling in place sealing the edges of the tape lengths of more than 0.2 m at one extreme or two or more internal seams (when you break three or more stitches of the seam), and the detachment of the edges of the tape or sewing tape the loop to a length of more than 10% of the length of embedment of the ends of the strips;
surface outcrops thread strips with a total length of more than 10% of the width of the tape caused by the mechanical action of the sharp edges of the cargo;
– damage to tapes from impact of chemicals (acid, alkali, solvents, petroleum products, etc.) with a total length of more than 10% of the width and length of a single line or more than 10% of the width and length more than 50 mm;
– buckling of the filaments of the strip line at a distance of more than 10% of the width of the tape, including through holes with a diameter of more than 10% of the width of the tape from exposure to sharp objects;
– the burned through holes with a diameter of more than 10% of the width of the tape sling from exposure to splashes of molten metal or the presence of more than three openings when the distance between them is less than 10% of the width of the tape regardless of the diameter of the holes;
– contamination of the strips, petroleum, resins, paints, cement, soil etc. more than 50% of the length of the lanyard;
bundle strands of tape slings.
Rope slings – the most common category of products. The working body, formed by ropes of length 1-50 m, weaves in many strands of steel wires having the same diameter. Depending on the performance of retaining the end loops, they are compressed and tied, and given the involved branch – and odnogolosyj mnogovetvevye. Usually one end of the lanyard is equipped with a carbine, the other a hook. In mnogovetvevye models of carbines are connected to a steel ring. The optimal number of branches and variants of the seizure of goods chosen for each working situation.
Also in this category, there are varieties of slings with a ring and two-loop construction (chalky). They are used separately or combined into a universal rope knots (USK). The cable slings may move any types of lifting devices of both conventional and bulky or very heavy loads (0.6 – 20 ton), with rings, shackles, eyelets. Therefore, they can be equipped with various grippers. Equipment in this category has good resistance to big dynamic loads in a wide temperature range (-40 0C to +45 0C), and its margin of safety is increased at 6.0 or more times the design effort.
All models rope slings are characterized by reliability, flexibility and low cost. They have uniformly produced the composite elements, however, there are limitations on the use in aggressive environments and for moving fragile goods. Also has a large own weight, the peelability and is not repairable. Product marking the following:
– 1CK – product with one rope line braided or pressurized aluminum sleeve;
– 2CK model with two rope branches used in a warehouse lifting work;
– 3CK (4CK) – node three (four) branches operating in the construction and designed for lifting loads with a large mass;
– UPC – analogue 1SK, but with branches in the form of loops (УСК1);
– CKK – strop-ring fasteners on their own branches (УСК2).
Chain slings are also widely used category associated mainly with loading and construction works. Body slings – steel chain with welded links. Due to the high strength and high flexibility, they can move loads that have sharp edges and a large mass (from 1 to 67 tons). They can withstand acidic and alkaline environment, low and very high temperatures (from -45 0C to 400 0C), until the open fire and other extreme factors. The mobility of the slinging can be used in any operation where the work to other categories of the sling impossible.
Chain slings differ significant weight, but it is possible to reduce it if you use high-tech alloys. They are safe, easy to use, versatile. They have a special protective coating and exceptional durability due to the possibility of replacement of individual links if they are stretching or tearing. Important only the timely monitoring slings both visually and using measurements. Good hosts periodically check for step between the links and their diameter.
Counterparts like rope, chain slings are odnogolosyj and mnogovetvevye and closed ring. Their price is higher than other categories strop, but the lifetime is practically unlimited, it is possible to adjust the lengths of the branches (from 0.5 to 20 m). They are also easily cleaned and conveniently stored. The products have such marking:
– 1СЦ – odnovolova slings (settings are specified in the passports);
– 2СЦ – reinforced dvuhvetvevym products to move heavy loads;
– 3СЦ (4СЦ) – mnogovetvevye slings used in moving odd-shaped loads with maximum safety;
– USTs – universal ring model for extreme conditions (move pipe and cargo with sharp edges);
– CC and OT – chain branches and closed.
Textile slings – this is the most modern and lean fit of a durable polyester material with tape (width 30 – 300 mm) or round (diameter: 6 – 90 mm) weave. They are suitable for moving goods of any size and weight, including those that require particularly careful handling: easily deformable, fragile, newly painted, etc. Durable synthetic fabric is able to withstand very high loads (0.5 – 15 t), but is afraid of sharp edges and rough surfaces. So slings often have special cases that protect them from abrasion. These accessories help to protect against accidental damage of the goods.
Textile slings produce loop, ring and krugoobraznymi. They have low weight and high flexibility, can be used in a wide temperature range (from -60 0C to +100 0C), resistant to solvents, oil, most acids, sea water and alkali. Products in this category are characterized by high resistivity and low water absorption and minimal elongation. They are equipped with two belt layers and a protective spetstkani in the joints with hinges.
The use of textile slings saves time loading and unloading, allows to increase the speed of works and quality of their conduct. The fixtures are light weight, easy to transport, they are not afraid of heat and cold, water and light. Also they are much safer in comparison with alternative metal counterparts.
In addition to the required tags from the textile strop to determine capacity there are color-coded. Purple colored slings that can withstand up to 1 ton, green – to yellow – to three. Gray says about the possibilities of the product to raise 4 tons of cargo, red five, brown six. The highest at the blue and orange lines. They are designed for 8 and 10 tons respectively.
Performing the loading or construction work, straps are usually used with additional devices. They can be equipped with:
– hooks – the most popular items in loading and unloading. There are many forms and modifications;
– links used for hanging and connecting individual branch (part of branches) with each other;
– carbines, performing the role of reliable fasteners with fixing;
– kosami iron teardrop rings with grooves, curved edge of which is tied around a rope;
– cargo grips, which allows to move complicated and bulky goods such as sheet metal, rolled steel, pipes, pallets, building boards and blocks. This advanced types of hooks or handles, with swivel lugs, Cams, forks, clamps, screws, pliers. They do not apply to inventory products and projected requirements;
– traverses – removable lifting means, in which connected to each other beams. They are mounting, magnetic, lifting, normal and telescopic. They travel container, rails, pipes and coils, unload cars. The traverse belong to the original equipment, manufactured individually to the needs of customers.
Hooks and links for slings:
Hooks – reliable coupling elements, connecting the load with the sling. There are male (open) and sling (with snapping). The most common ones (SALK) have the eyelet, and the spring-loaded latch. The finger is a splint. Other used forklift pair, wide throat without safety lock, self-closing hinges, shortening and limiting design. There are hooks-swivels with bearings and hooks the chokers round shape. All kinds of products are parts of the lifting mechanism, which includes alloy steel.
Links are stropalnye and standard coupling of functions, it is separable (in different versions) and one-piece design, as well as ovoid, oval (Ov) and triangular (RT) form. Is used in their manufacture round steel, connect the contact welding or fusing, and the production is regulated by GOST 25573-82.Also there are varieties of high-strength parts made of special alloys and spiral eights with a turnbuckle adjustable in length. To evenly distribute the load, sometimes together with links are used for additional rings.
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