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TECHNICAL INSPECTION OF JACKS
Each rack, screw and hydraulic jack must have a manufacturer's data sheet and a plate indicating the lifting capacity.
Jacks in operation are subject to technical examination and testing in accordance with paragraph 5.53 of SNIP ΙΙΙ-Α.ΙΙ-62 at least after 12 months.
The test of jacks during the technical examination must be carried out for a static load exceeding the maximum rated carrying capacity by at least 10%. The jack must be under this load for 10 minutes, and the screw (rail, rod) must be extended to the uppermost position. For hydraulic jacks, by the end of the test, a pressure drop of more than 5% is not allowed. The test results are entered in the passport.
UNIVERSAL STAND FOR RIGGING EQUIPMENT TESTING
In fig. 5-7 shows a universal stand designed for testing blocks, hoists, jacks and mounting belts for a maximum load of 15 tons.
Figure: 5-7. Universal rig for testing rigging equipment,
The stand consists of a reinforced concrete foundation on which two supporting I-beams 1 are fixed. Two pipes 2 0 219X4.5 mm, 12 m high, are installed on the beams' consoles.
A crossbar 3 moves along the pipes, on which a dynamometer 4 is fixed, two rods 5 are also fixed to the crossbar for testing jacks. A fixed block is attached to the upper beam 6, a winch 7 is installed on the beams 1. A plate 8 is welded to the consoles of the beams 1, and plate 9 is welded to it, in which, as in the cross member 3, there is a hole for the thrust, with which they can be connected to each other with a friend.
When testing slings, blocks and hoists, this thrust must be installed, and when testing jacks it is removed.
The load on the tested slings, blocks and jacks is created by a winch through a chain hoist system; the load on the hoists can be created by the hoists themselves. The load is indicated by a dynamometer.
WORKING WITH THE JACK
Order on the appointment of responsible persons when working with a jack
For safe operation and organization maintenance jacks available at the enterprise, in accordance with the requirements of the normative and technical acts governing the work with devices, "Rules for working with tools and devices", approved. by order of the Ministry of Labor and Social Protection of the Russian Federation of August 18, 2013 N 552n,
I ORDER:
1. Appoint persons responsible for the organization and safe work with jacks, for the maintenance of jacks in good condition:
- Filatova A.A., mechanic of the transport department,
- Tulumbayev A.A., head of the boiler room.
2. Responsible persons appointed in clause 1. of this order:
2.1. Carry out maintenance, repair, technical inspection of jacks in accordance with the requirements technical documentation manufacturer;
2.2. Check the serviceability of the hydraulic jack before each use by performing an inspection;
2.3. Ensure the presence of a plate on the body of the jack indicating the inventory number, carrying capacity, date of the next technical examination;
2.4. Conduct periodic technical inspection of jacks in operation at least once every 12 months, as well as after repair or replacement of critical parts. Technical examination screw and rack jacks produce by inspection without static test... Technical examination of pneumatic and hydraulic jacks shall be carried out by inspection and carrying out a static test;
2.5. Do not allow faulty jacks or jacks that have not passed the technical examination;
2.6. The results of inspections, repairs, inspections, tests and technical examinations of jacks shall be entered in "";
3. The organization and performance of work with jacks in order to ensure the safety of workers performing them, and persons in the area of \u200b\u200btheir production, should be carried out in strict accordance with the normative documentation on labor protection (clause 43 of "Rules for labor protection when working with tools and devices" ).
4. Control over the execution of this order shall be entrusted to the chief engineer A.A. Vasiliev.
Director P.P. Pavlov
Testing of off-road rack and pinion jacks
Nowadays hi-jacks of two brands are on free sale: the American Hi-Lift and the Russian Sorokinstrument. Experienced jeepers will probably have Canadian Jack-All, but you will not find them on the shelves and in price lists for a long time. And even at the time of its active presence on the Russian market, the area of \u200b\u200bdistribution of "Canadians" was not so wide as to take them into account in our test. Today they are rather collectible rarities, and not a tool of "off-road labor". As well as hi-jacks from other manufacturers, which were never officially supplied to us and came across in single copies. And this is despite the fact that among the latter there may be interesting models for research (for example, Tiger Jack from the American "Maasdam Pow'r-Pull Inc." - they are given a lifetime warranty). In general, today we decided to focus only on models that are available to the Russian buyer.
The Hi-Lift Jack Company produces two types of rack and pinion jacks. According to the manufacturers, the "red series" is completely made of cast iron, with the exception of the steel handle, bolts and support pins. In the "black" part of the parts, including the support platform, the upper eyelet and some levers of the mechanism, are steel. Reiki, according to the manufacturer, is the same for both options. The prices are almost the same (the black model costs $ 5 less than the red one of the same length). Despite this, each color has its own adherents and, according to the reviews of sellers, there are even regional preferences. So, Moscow mostly buys red high-elevators, but they almost stopped taking them to the Urals - only black ones ask. In short, both here and there they consider “their” color stronger.
Those who are trying to save money (regardless of geography) opt for the hi-jack offered by the Sorokinstrument chain of stores. Their jack, which was previously sold under the name "farm jack", and now has become just a "high jack", costs about one and a half times cheaper than the "lift". By design, it is similar to overseas competitors, except for the nuances. So, the handle here is made non-separable, and not bolts and nuts are used as the axes of the levers of the mechanism, but cotter pins. In this case, the rail is fastened to the sole, on the contrary, by a bolt. In addition, in this model, the end of the handle is covered with a rubber cover, and the role of its lock in the vertical position is played by two plates welded to it. By the way, as practice shows, over time they unbend and stop performing their function. The curly spring ring, designed for the same purpose in the "Americans", has shown itself to be more reliable.
Since we have touched upon the "national question", let us dwell on it in more detail. The origin of Hi-Lift jacks is beyond doubt: Bloomfield, Illinois, USA. Their competitor's pedigree is not so clear. The passport, recently attached to the Sorokin hi-jacks, states: "Manufactured by Torin Jacks Inc., USA", and this despite the fact that these same instruments were previously sold as Dutch! And although evil tongues will claim that they are stamped in China, in order to avoid confusion in terminology, we will conventionally call the Sorokin jacks "ours", since they are sold under a domestic trademark.
For testing, we took the three longest versions of each model: HL-604, HL-605, and 5.8605. At first glance, jacks are very similar. Similar overall dimensions, similar design, the same principle of operation, and the rails are completely interchangeable. Indeed, profile dimensions the subjects are very close, and the distance between the holes of the laths in all three specimens is completely the same. The only thing that is striking is the difference in the design of the handles of the representatives of competing brands and the stamped flat top eyelet of the HL-604 adapted exclusively for attaching the cable. "Red-skinned American" and "our", on the contrary, are able to work as presses (clamps) due to the fact that, being turned across the rail, their powerful upper eye becomes a reliable stop. But there are also nuances, so if Sorokin 
the lug is constantly in the "clamping" position (configuration features do not allow turning it over in another way), then in the cast-iron Hi-Lift it rotates around its axis without any problems, which simplifies both transportation and work as a winch.
The first test was lifting a heavy Toyota LC on a country road ... All three jacks certainly did the job. The wheel was suspended high enough to be changed, and the car remained stable. With the further rise of another thirty centimeters in all cases, the balance was disturbed and the car smoothly slid to the side. In general, everything is as it should be on an uneven surface. However, interesting moments have already emerged here. So, 
the mechanism of the "black American" we inherited refused to move freely up the rail, and it had to be "pumped" even without load, and the "sorokin" had an elastic band falling off the handle. However, we attributed both to the individual shortcomings of specific specimens (completely curable in capable hands). However, they can be used to indirectly judge the stability of quality and production culture. But the paint peeling off in shreds on the "elevators" and the falling out cotter pins at the "farm" are, alas, statistics that are repeated on almost every copy. If we talk about the convenience of work, then we did not notice much difference between the three models. Unless the effort on the handle when lifting the car by "our" hi-jack subjectively seemed a little more than that of the "Americans", and the work of the mechanism - a little harder.
Our measurements
* from the axis of attachment
** without rubber cover
The correctness of our feelings was also confirmed by an impartial technique ... Measurements in a special laboratory of NICIAMT showed that the lever mechanism of each of the hi-jacks transmits the effort developed by the handle to the lifting platform in a different way. The maximum gear ratio was found in the black (steel) Hi-Lift, the minimum - in the Sorokinsky. The difference was about 15%. At the same time, the characteristics of the red (cast-iron) "American" are located approximately in the middle. Along the way, some nonlinearity of the force conversion characteristic of all three jacks was revealed. The more you load the handle, the higher is the gear ratio of the entire mechanism. Most likely, this is due to a change in the force vector during the working stroke of the handle and levers.
Along the way, we took another measurement: what is the maximum effort a person can develop with the help of a jack. Tellingly, in each approach, different results were obtained, even with the same tester. The lift proved to be very sensitive to how the “operator” stands, how he holds the handle, and even more so how he presses on it. However, no matter how hard we tried, no one managed to lift more than 2.5 tons. According to our calculations, taking this weight would require a hero with a mass of about a centner, and there was no such in our company that day ...
Now try to guess what a normal jeep will do if he needs to lift more than his own strength allows. There are two answers. He will either call another jeep for help and they will take the weight together, or simply lengthen the handle with a piece of pipe and win on his own. Yes, despite all the warnings in the instructions for the jacks that you can't do this, that's exactly what everyone does. And where to go if there is no other chance of salvation from the mud? We simulated such a situation by lengthening the handle to 190 cm. The laws of physics did not lie: it became several times easier to work. Now you can feel the lifting capacity of the jacks (in all cases declared by the manufacturers at the level of three tons) ...
Again we clamp the jacks in turn into a special stand with weights and now we press on the handle until something breaks. All three mechanisms are set at the same height - 1160 mm to the plane of the beak (in other words, at the top of the rail, a few clicks to the maximum), and the handles are lengthened. It is in such situations that the slats usually bend and mechanisms break off on the off-road ... Our laboratory experience differs from the jeep realities only in that we put each jack strictly vertically on a flat plane for a long time, simulating an ideal situation.
Black Hi-Lift was the first to hit the block. When the load on the beak approached the 2750 kg mark, the lateral deflection of the staff became visually noticeable. However, as the pressure on the handle increased, the lifting mass continued to increase, and soon the scale arrow crossed the three-ton mark. The deformation of the rail became more and more noticeable, the handle was slightly bent, but the jack continued to do its job. Only at around 3300 there was a crash, something flew near my ear, and the hi-jack collapsed. It turned out that the bolt, which performs the function of the supporting axis of the intermediate lever of the mechanism, could not stand. The lever, bent from a steel plate, simply cut it like scissors in two places (one of the pieces went free flight). At the same time, the mechanism flipped to the "descent" position, and the jack lost its balance. If he had a car, she would have fallen! As for the rail, despite a very noticeable bend during the ascent, it returned to its original state and again became perfectly straight ...
Now it's the turn of the red "elevator". On his account there was a suspicion that the thick cast lever would not be able to quickly cut the bolt and the jack would last longer (of course, if another part did not break). However, in terms of behavior under extreme loads, this specimen turned out to be similar to its black brother. At about the same figures, a lateral deformation of the rack appeared on the scales and began to gradually increase. However, we did not wait for the bend of the handle. But the already familiar bolt broke, but, as expected, a little later. Beyond the 3500 kg mark. At the same time, the mechanism flipped and fell down. What does a jeep in the forest do in such a situation? Finds the first hardened pin that matches the diameter, and again gets a workable hi-jack. However, the instruction for Hi-Lift explicitly prohibits such repairs, requiring only the original spare part from the repair kit to be installed. The fact is that the fracture of this bolt with the calculated strength is programmed by the manufacturers as a kind of fuse that does not allow more serious damage to the jack during overload. In both cases, it worked. There are no other obvious defects that prevent the use of jacks.
Now it's the turn of Sorokinstrument. He has a thicker pin in place of the bolt. I wonder if he also serves as a fuse or will we see a different scenario? We push! After 2600 kg, the rail bends slightly, but not across, but ... along the long side. We press it to almost 2800 kg - and here the handle becomes fluid. In this case, the load drops again by 2600 kg, but the jack maintains balance and continues to stand as if nothing had happened. The handle is bent in a half-ring, but not an ounce of sense. Had the jack sustained the declared three tons, this "overload" option would have been the best - the safest, at the same time visual and preserving further field operability of the instrument without any urgent need for repair (the rail, as in the two previous cases, straightened out after removing the load).
So, the first execution was tolerated by all three copies. "The Americans" after a minute of repair are ready to return to service, "our", albeit with a crooked handle, is fully operational. So what kind of load is needed to make the "irreparable" happen?
The answer to the question asked was given by the last test. Weighty, rough and visible ... We decided to simply load the jacks with a mighty press, resting the heel on one plate, and the beak on the other. We bring the mechanisms almost to their full stroke - 1260 mm, and before starting the experiment, we fix each of the jacks in the press, strictly observing the vertical and horizontal position.
I must say, the results of this test puzzled us a lot. The black "lift" proved to be the most persistent. The rail was bent, but held for a very long time. Only with a load of 3600 kg there was a loud bang, like a shot, and the jack folded across the rail. We expected something like this. But the behavior of the cast-iron "elevator" puzzled us - it simply and softly formed when the load reached only ... 1700 kg. "Sorokinstrument" was not much stronger: its rail could not withstand the load of 1750 kg and also formed, but more sharply.
In an attempt to explain what happened, or rather, the sudden weakness of the two red competitors, we settled on two versions. The first is that during the previous test, we practically overcame the stability limit of the rails, and irreversible deformation, which was imperceptible to the eye, occurred in them, possibly even with a change in the metal structure. Therefore, the fuse only worked correctly in the “combined” Hi-Lift. The second version - when the press moved in two cases, the position of the jack was violated and it moved relative to the position initially set in terms of level and plumb line. That is, it actually acquired a slope while continuing to increase the load, simulating a situation when the car is already starting to collapse, but it is still being raised. Such a significant decrease in carrying capacity in this case is explained by a change in the pressure vector.
What conclusions follow from this? In our opinion, the situation is quite obvious. Everything can be broken. But even if we take into account the likelihood of quality differences between different batches of the same brand, the strength of Hi-Lift is objectively higher than that of Sorokin. At the same time, for most SUVs, any of our three will work, just as we would not recommend one for pulling a truck. As for the features of the application, they are also similar: remember that the warnings about replacing safety bolts and lengthening the handles in the instructions are not written for the sake of an elegant style.
But it makes no sense to edit an already bent rail. It's like editing a bent nail. It is impossible to make it perfectly even the second time. In addition, during the appearance of irreversible deformation, the structure of the metal is disturbed and the carrying capacity becomes much less.
Chemical attack.
To comment on the results of the experiments and to conduct a spectral analysis of the material of the slats, we asked the metallurgists from the Research Institute of Inorganic Materials. academician Bochvar. Experts considered both of our assumptions about the difference in loads sustained by each of the hi-jacks in the first and second experiments to be correct. The conclusion that the metal fatigue occurred after the first test, according to the authoritative opinion, is more suitable for ideal laboratory conditions than the suspicion of displacement of the test sample, fixed in the press.
As for the material from which the slats are made, the result of the analysis surprised us. In terms of chemical composition, all three slats turned out to be very close, although not absolutely identical. But the material turned out to be steel. Moreover, the most ordinary, unalloyed. According to metallurgists, there can be no talk of any pig iron declared by both manufacturers with a carbon content of less than 0.5%. Cast irons should contain this element in the range of 2-4%. But this is also good - harder, but brittle cast iron would hardly withstand a much greater load, however, if deformed, the rail would not bend, but break in half, which, in our opinion, is much more dangerous in any case. In addition, in case of accidental strikes on the rail, inevitable during the operation of the jack, its metal could begin to crumble.
If we talk about the differences in withstanding load between jacks different manufacturers, then with a similar chemical composition the strength of the rail is determined by only one thing - the features of the material processing, during which the steel receives additional strength. It is in this that the secret of the ultimate hi-jack stability is hidden.
The chemical composition of the rails (mass fraction,%)
Reliable and trouble-free operation of the pumping unit largely depends on how correctly the design, material of units and parts are selected, as well as how the hydraulic parameters of the unit correspond to the features of the technological scheme in which it is installed.
The nature of the extinguishing agent outflow, hydraulic parameters and effective range * of the explosion suppressor
The use of a pyrotechnic composition as a gas generator makes it possible to provide the required mode ~ pressure of the working fluid, and, consequently, the necessary hydraulic parameters for the outflow and delivery of the extinguishing agent to the combustion zone.
Sprinkler hydraulic parameters:
Hydraulic parameters of the sprinkler EG-3.5:
EG-12 sprinkler hydraulic parameters:
The generator with a double-jet spray GDS-3,7 * has the following hydraulic parameters:
The GES generator has a four-jet sprayer and is an upgrade of the GDS generator. Below are the hydraulic parameters of the generator:
Water pipelines for various purposes should be used as a source of water supply for water fire extinguishing installations. If the hydraulic parameters of the water supply (pressure, flow) do not provide the design parameters of the installation, it should be provided pumping station to increase the pressure.
Irrigation maps at. using an involute sprinkler (sprinkler or drencher) are shown in Fig. V-14. Sprinkler hydraulic parameters are given in table. V-6.
Table V-6. Sprinkler hydraulic parameters
jacking devices were installed on the columns, with the help of which the covering elements and crane beams were lifted to the design height; at the same time, four overhead cranes were securely attached to the crane girders. Then the old columns were cut and the upper part of the building frame with an area of \u200b\u200babout 4 thousand m2 was lifted to a height of 6 m. The total weight of the structures being lifted was 800 tons; their lifting was carried out using 24 hydraulic jacks with a lifting capacity of 400 tf for 10 days.
The jacks are tested for a load that exceeds the ultimate carrying capacity by at least 10%. The jack should be kept under this load for 10 minutes. The test should be carried out with the screw, rail or rod fully extended. Jacks should be tested once a year. For hydraulic jacks, a pressure drop of no more than 5% is allowed within 10 minutes. For rack and pinion jacks, thread or tooth wear is allowed no more than 10%.
The test of jacks during the technical examination should be carried out at least after 12 months for a static load exceeding the rated carrying capacity by 10%. The jack must be under this load for 10 minutes, and the screw (rail, rod) must be extended to the uppermost position. For hydraulic jacks, a pressure drop of more than 5% is not allowed at the end of the test. The test results are entered in the passport.
the bridge was destroyed and rebuilt three times. Last time it was undermined by the Germans during their retreat in 1944 with the expectation of complete destruction. The explosion in one of the middle panels of the arch was completely broken and deformed. The tops of the bulls and the abutments were destroyed. The arches of the navigable span, broken into two semi-arches, turned in the longitudinal and transverse directions during the fall and, having moved from the supports, as if jammed one another. The bridge was rebuilt according to the project and under the supervision of engineer S.T.Sokhransky according to the work flow diagram shown in Fig. 11.2. The lifting of the semi-arches was especially difficult, since they had to be lifted in the longitudinal and transverse directions, aligned the oblique over the supports and moved over them in design position... The right semi-arch was lifted by a combined method using at the channel end of the farm lifts attached to two tower supports, and at the coastal end - two-hundred-ton hydraulic jacks on cobblestone cages. The left semi-arch and the surviving part of the coastal superstructures were raised with the help of jacks and pulley blocks attached to wooden portals, towers or stone cages. The restoration work was completed in seven months with the help of qualified riveters, welders and divers.
2 The blast furnace, blown up within the tuyere zone, sank by 3.5 m and simultaneously shifted to the side by 1.5 m, and the difference in the marks of the opposite points of the moratorium ring reached 0.6 m. The mass of the settled structures of the metal casing was 1200 tons. was produced as follows. At first, under the moratorium ring of the blast furnace, five supports from metal pipesthat have taken the load of the furnace. Then the lining was dismantled. The blast furnace was secured with six braces, and the descending gas pipelines were suspended from the masts. Subsequently, the temporary supports were removed, and the mass of the furnace was taken up by lifting devices. The furnace was lifted and leveled by three separate banks of five hydraulic jacks with a lifting capacity of 200 tons each. To recharge the jacks, two types of metal packages were used: from rails with a height of 140 mm for busting after one pumping out of the jacks and beam 800 mm from pipes to replace 5-6 cages from rail packages. First, a one-sided lifting of the blast furnace was carried out on two supports by rotating it in.
For hydraulic jacks, by the end of the test, the pressure drop should not exceed 5%.
Walkways consist of metal sleds, gutters, mechanical (hydraulic) jacks and racks. The chute is designed to facilitate the ejection of pipes onto the walkway. To reduce the coefficient of friction when moving the pipe along the chute, it is recommended to cover the bottom of the chute with a slippery coating (slippery plastic).
At present, all newly commissioned wells are equipped with reinforced concrete platforms for mobile units, as well as wellhead platforms and bridges made of reinforced concrete slabs. Preparatory work much easier with the use of movable walkways. Walkways with a gutter (Fig. 24) consist of transport sleds 1, platform 2, gutter 5, mechanical or hydraulic jacks and a set of racks 3. The design allows you to change the slope of the gutter and racks 4. During transportation, the platform is dismantled and placed in a sled.
in the case of the raised load, the locking pawl is retracted at the ratchets, and the non-return valve at the hydraulic jacks opens.
5.1.3. The controls for the lifting and lowering operations of the unit should be concentrated on an independent panel equipped with the necessary control and measuring instruments, located in a safe place and providing visibility of the tower, mast, hydraulic jacks, winches and other mechanisms installed on the unit.
Prestressed concrete is especially widely used in the construction of bridges, as well as in the construction of structures calculated according to the theory of plasticity. A steel wire reinforcement strand wrapped in a steel sheet or plastic sheath is poured with concrete in the same way as the reinforcement. The ends of the strands or bundles are terminated on the main plates in such a way that the prestressed concrete hoists can be pulled to the stops by hydraulic jacks even before the structural elements are loaded.
Tests of jacks (1 time per year) should be carried out with a static load more than the limit by 10% (according to the passport) for 10 minutes when the rod is in the upper extreme position.
The test of jacks (with a periodic technical examination) should be carried out with a static load, 10% higher than the maximum (according to the passport), within 10 minutes when the rod is in the upper extreme position.
The test of jacks (once a year) should be carried out with a static load more than the limit by 10% (according to the passport) for 10 minutes when the rod is in the upper extreme position.
Jacks are tested annually. The test results are entered in the passport, a stamp or stencil is placed indicating the load and the date of the test.
When testing jacks, their screws (rails, rods) must be pushed to the uppermost position corresponding to lifting the load to the maximum height according to the operational documentation.
When testing slings, blocks and hoists, this thrust must be installed, and when testing jacks it is removed.
A crossbar 3 moves along the pipes, on which a dynamometer 4 is fixed, two rods 5 are also fixed to the crossbar for testing jacks. A plate 8 is welded to the beams / consoles, and plate 9 is welded to it, in which, as in the cross member 3, there is an opening for a rod, with which they can be connected to each other.
When working with a hydraulic jack, it is not allowed to stand in front of its safety plug. The test of jacks during their periodic technical examination should be carried out with a static load exceeding its maximum rated carrying capacity by at least 10% for 10 minutes; in this case, its stem (rail, screw) must be installed in the uppermost position.
Each domzrat must indicate the inventory number, carrying capacity, date of the next test and belonging to the unit. The date and results of tests of jacks are entered in the Register of accounting and inspection of rigging means, mechanisms and devices, indicating the date of the next test, as well as information about the repairs performed or replacement of critical parts.
Each rack or screw jack must have a passport. There is a number on the body of the jack and its capacity is indicated. In the absence of a passport, it is necessary to test the jack to establish its carrying capacity.
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