What is a Mayevsky crane valve, how to choose, install and use it correctly

Cargo tilting

Cargo tilting by cranes should be carried out on tilting platforms or in specially designated places. The performance of such work is permitted only according to a pre-compiled technology that determines the sequence of the operation, the method of slinging the load and instructions for the safe performance of work.

The tilting of structures at a construction site during installation or assembly should be carried out according to specially developed technological schemes, which should reflect the technological sequence of operations, the exclusion of oblique tension of cargo ropes, instructions for the safe performance of work, and also indicate the methods of slinging structures.

The dimensions of the platforms are determined taking into account the dimensions of the products to be turned and the scope of work for maintenance and turning. An emphasis is installed on the tilting platforms to prevent structures from sliding. It is forbidden to carry out tilting of goods directly in the stacks.

Where should air vents be installed?

When installing a heating system, installing air vents is a mandatory procedure; to determine the right amount, you need to know where to put these devices. Air vents are recommended to be located in the following places:

The highest points of the system. If during installation the pipeline rises up, bypassing any obstacle, and then goes down to the heat exchangers, an automatic air vent for the heating system should be installed from above. This will prevent air build-up because light air always rises and collects in the piping on the top floor.

Rice. 9 Types of automatic air vents

• Heating radiators. Radiator heat exchangers have a complex shape, which includes a large number of sections - this creates convenient cavities for air accumulation. Therefore, Mayevsky outlet valves are always used in radiators; in an individual heating circuit, they are installed on each radiator, regardless of the connection scheme (single-pipe, two-pipe, lower, side, diagonal). Radiator manual models of exhaust valves, unlike automatic ones, are small in size, less expensive, fit aesthetically into the radiator circuit, therefore they are installed on batteries in the vast majority of cases by the manufacturer and, if necessary, by the owners of houses.
• Towel dryers. Towel warmers produced by the industry of a complex “ladder” shape popular in everyday life are always equipped with an air vent with a straight pipe located in its upper part. It is more convenient if the heated towel rail is equipped with an automatic air vent for the following reasons: the manual model screw located at the top is inconvenient to tighten, water may periodically be absent in residential buildings and manual adjustment becomes troublesome, besides, the channel protruding from the side spoils the aesthetic appearance of the heater.
• U-shaped branches and bypasses. Any section of the pipeline with an upward loop collects air, if a shut-off valve is used to turn off the loop, it is installed at the highest point using a model with a built-in Mayevsky automatic valve (naturally, the air vent at the top can also be installed separately from the valve).
• Boiler piping system. It is also recommended to equip the boiler piping with a valve to ensure the safe operation of the heating equipment in case of air in the line.
• Hydroguns.Not so often in domestic heating systems, hydraulic arrows are used, to which circulation pumps, radiator and underfloor heating collectors are connected - if the device is located vertically, an automatic air bleeder is screwed into its upper part.
• Collectors. When installing multi-circuit underfloor heating, collectors with combs are used, to which a pipeline of various circuits is connected. The collectors are located above the level of the water floors and are always equipped with automatic air vents that are installed in their housing by the manufacturer; the system includes two devices for the supply and return lines.

Rice. 10 Manual and automatic air vents in the heating system - layout diagram

What should be the correct structure of the system

Automatic air vent - a simple design device that does not allow air to accumulate in the system

When designing, it should be foreseen that air can accumulate in horizontal pipes, and how to bleed it from the heating system will be a difficult task.

Therefore, it is important that the top supply pipe has a slight slope, starting from the riser and further in the direction of the coolant. At the highest point, a device is installed that allows you to bleed air from the heating

It can be a regular faucet or Mayevsky faucet, but it is better to use an automatic air vent. In a more complex heating system, air vents are installed in all places where an airing problem may occur. Then there will be no question of how to bleed air in one or more heating radiators, since the accumulating bubbles will be gradually bled from each group of elements that make up the system.

The return pipe must be laid with a slope towards the boiler. This is done to combat air congestion, and also so that you do not have to guess how to drain water from the heating system if repairs are needed.

If the heating system is equipped with a circulation pump, then there is no need to observe the slope of the pipes with great accuracy. And yet, for the effectiveness of the system, it is desirable to lay pipelines with the correct slope.

Finally, we can recommend that you always contact a specialist about problems with heating. They know how to design a workable system and advise on how to bleed air that has accumulated in radiators. But the homeowners themselves must, on the eve of the heating season, carry out a preventive inspection and check of their heating system.

The video gives a visual explanation of how to bleed the air from the radiator:

Installation of internal water supply and sewerage systems

The design documentation used in the repair, reconstruction or modernization of the substation, as well as the final documentation based on the results of the work performed, should include repair working drawings and, if necessary, a description of the sequence of work and the performance of critical operations. The organization performing the repair, reconstruction or modernization of the substation must perform the specified work in accordance with the developed specifications, if these requirements are not in the manual of the substation operation manual. In the case of welding, the specifications must be developed taking into account paragraphs 68 - 82 of these FNP and contain instructions on the metals and welding materials used, methods for controlling the quality of welding, rejection rates for welded joints, as well as the procedure for acceptance from repair of individual units and finished products. Monitoring compliance by a specialized organization with the requirements of technical specifications, repair drawings and technology for the production of repair work should be carried out by the service of the technical control department, hereinafter referred to as the QCD of a specialized organization performing repair work.The quality control of the repair of reconstruction, modernization of the substation must be confirmed by the Protocol. The quality control of the repair of the rail track must be confirmed by the certificate of acceptance of the rail track for the substations moving on rails. Upon completion of the repair, reconstruction or modernization of the substation, a specialized organization is obliged to make an entry in the passport of the substation reflecting the nature of the work performed and provide information copies of the certificates of the materials used. An organization that has performed repairs or reconstructions of poor quality is liable in accordance with applicable law.

Air vents for heating systems principle of operation

To bleed air from the circuit, you can use a conventional valve, draining some of the liquid. If in communal houses a decrease in the volume of water in the circuit does not cause negative consequences and it is replenished by public utilities, then in individual houses the drained coolant will have to be replenished independently.

For a closed system, topping up the coolant is a rather big problem - you will have to connect a manual or electric pump, and if there is poisonous ethylene glycol antifreeze in the line, work with the necessary safety measures will take a lot of time.

The main difference between special air vent devices and conventional valve locks is the small diameter of the outlet, its location at an angle of 90 degrees and the possibility of smoothly adjusting the cross section of the outlet channel with a threaded screw.

As can be seen from fig. 2, the screw has a conical shape and a similar seat, due to which, when closed, it reliably and tightly closes the inlet. To bleed the air, the screw head is turned one or two turns, opening the outlet drain hole of small diameter, and the airy coolant, together with the bubbles, will begin to flow out of the tap in small quantities, while the air lock will be bled more intensively.

The advantage of using an air vent is that when the screw is turned, first of all, with a characteristic hissing sound, the air flow comes out, and then the air coolant flows out, a small amount of which can not be added to the system.

Fig.3 The principle of operation of the automatic air vent

Job site requirements

The crane owner or operator must:

• develop and issue to the places of work projects for the production of construction and installation works with cranes, flow charts for warehousing goods, loading and unloading vehicles and rolling stock, and other technological regulations;
• familiarize (on receipt) with the projects and other technological regulations of persons responsible for the safe performance of work by cranes, crane operators and slingers;
• provide slingers with distinctive signs, tested and marked load-handling devices and containers, corresponding to the mass and nature of the goods being moved;
• post at the work site a list of the main cargoes moved by the crane, indicating their mass. Crane operators and slingers servicing jib cranes during construction and installation work, such a list should be handed out;
• determine the sites and places for storing goods, equip them with the necessary technological equipment and devices (cassettes, pyramids, racks, ladders, stands, linings, gaskets, etc.) and instruct crane operators and slingers regarding the order and dimensions of storage.

Organizations operating cranes must establish a procedure for the exchange of signals between the slinger and the crane operator. Recommended sign signaling is given in Appendix 3.When erecting buildings and structures with a height of more than 36 m, two-way radio communications should be used. Sign signaling and a signal exchange system for radio communications should be included in the production instructions for crane operators and slingers.

The place of work for the movement of goods by cranes must be illuminated in accordance with the project for the production of works.

For the safe performance of work on the movement of goods by cranes, their owner and the manufacturer of the work must ensure that the following requirements are met:

• at the place of production of work on the movement of goods, as well as on the crane, the presence of persons who are not directly related to the work performed should not be allowed;
• a list of used load-handling devices and a graphic representation (scheme) of cargo slinging;
• places and dimensions of cargo storage, access roads, etc.;
• measures for the safe performance of work, taking into account the specific conditions at the site where the crane is installed (fencing of the construction site, installation area, etc.);
• it is not allowed to lower the load onto the car, as well as to lift the load when people are in the body or cab of the car. In places of constant loading and unloading of motor vehicles and gondola cars, stationary overpasses or hinged platforms for slingers should be installed. Loading and unloading of gondola cars with hook cranes should be carried out according to the technology approved by the manufacturer of the work, which should determine the location of the slingers when moving goods, as well as the possibility of their access to overpasses and hinged platforms. The presence of people in gondola cars when lifting and lowering loads by a crane is not allowed.

Places of temporary or permanent location of workers should be located outside the hazardous areas.

At the boundaries of zones of permanent hazardous production factors, protective fences should be installed, and zones of potentially hazardous production factors - signal fences and safety signs.

The illumination of premises and sites where loading and unloading operations are carried out must comply with the requirements of the relevant building codes.

Installation of ball valves on batteries

A conventional ball valve is only designed to switch to 2 positions: "open" and "closed". It is impossible to regulate the flow of coolant through the radiator with it, only to block it. The figure below shows a simple connection diagram for a heater with this type of fitting:

The proposed scheme is the best option for an unregulated connection of a radiator to central heating risers in an apartment. You still don’t have to balance it, and it’s pointless to install a thermostatic valve because of the poor quality of the coolant. Instead of a ball valve at the outlet, the installation of a so-called shut-off valve is also practiced, its difference is only in appearance.

Depending on the layout of appliances and heating pipes, you can choose an angle valve for a radiator with or without a decorative coating.

Also, when choosing a product, it is recommended to pay attention to the working pressure indicated on the body of the product or in its passport. It must correspond to the pressure in the heating network of an apartment building

Advice. Choose good thick-walled brass taps for mounting on a radiator and a connection with an American union nut. It will allow you to quickly disconnect the eyeliners without rotating the elements. On a single-pipe riser, be sure to install a bypass with a slight offset to the side of the main pipe.

Loads that must not be lifted with cranes

It is forbidden to lift a load weighing more than indicated in the crane passport. When operating hoisting machines, it is forbidden to lift loads whose mass exceeds the permissible load capacity, as well as loads with an unknown mass.It is forbidden to lift and move empty and filled cylinders with a magnetic crane.

It is forbidden to lift "dead" weight. “Dead” cargo includes: cargo buried in the ground, cargo pressed by another cargo, cargo frozen to the ground.

If the mass of the load to be lifted is unknown, it must not be lifted;

use a crane to release loads covered with earth, snow, structures and equipment frozen to the ground, bolted or filled with concrete, load-handling devices jammed by the load, as this leads to an unacceptable overload of the crane, which in most cases ends in a breakdown or accident;

lift reinforced concrete products with damaged mounting loops;

feed materials into window and door openings if they do not have lifting (unloading) platforms, as well as deliver a larger load than these platforms.

balancing valve

The valve for adjusting heating differs in design from a conventional ball valve in that it can smoothly close the flow area in a few turns. Moreover, after balancing, the position of the valve can be fixed so that no one accidentally violates the settings. This type of control valves is placed at the outlet of the radiator, as shown in the diagram:

Shown here is the connection to a two-pipe horizontal system, the most common in private houses and apartments with individual heating. By the way, the principle of mounting fittings with a single-pipe scheme remains the same. An ordinary ball valve is placed on the supply line, and an adjusting valve is placed on the return line. In the case when a system with vertical risers takes place in a two-story house, then the installation diagram of the associated fittings looks like this:

The principle of product selection is the same as in the previous section.

Direct or angular execution is accepted depending on the layout of equipment and pipelines, it is also important to use American women when assembling

Pay special attention to the quality of the casting and the thickness of the brass walls of the reinforcement. If you have networks of polypropylene pipes, do not rush to buy PPR taps, it is better to put adapters and reliable metal products

Advice. Balancing valves are placed on all radiators, except for the very last one, located at the dead end of the branch. On the connections to it, it is enough to put simple ball valves.

Feeding loads into floor openings

The supply of goods into the openings (hatches) of ceilings and coatings should be carried out according to a specially developed project. When feeding the load into the openings (hatches) of ceilings and coatings, it is necessary to lower the load and raise the hook with slings at a minimum speed without swinging them.

The distance between the edge of the opening (hatch) and the load (or hook block, if it is lowered into the opening (hatch)) must ensure the free movement of the load (or hook block) through the opening and must be at least 0.5 m.

In exceptional cases, it is allowed to reduce this distance when escorting the cargo through the opening (hatch) using a guy line.

The load brought to the opening (hatch) must be calmed from swinging and only after that it is lowered into the opening. When lifting the sling through the opening (hatch), all hooks must be hung on the detachable link, and the sling must be guided from below with a hemp rope; the hemp rope is unhooked from the sling after the sling is taken out of the opening (hatch). The slinger can approach the load (move away from the load) when the load is lowered (raised) to a height of not more than 1 m from the level of the surface (platform) where the slinger is located.

At the place of acceptance (or dispatch) of goods supplied (or removed) through the opening (hatch), as well as at the opening in the ceiling (covering), a light signaling (luminous inscriptions) must be equipped, warning both about the presence of cargo above the opening (hatch), and and about lowering it through the opening (hatch), as well as inscriptions and signs prohibiting people from being under the transported cargo.

Light signaling must be located so that it cannot be damaged by the transported load or lifting devices.

Radio communication must be established between the crane operator and the slinger, who is out of sight of the crane operator.

The opening (hatch) through which the load is fed must have a permanent fence with a height (distance from the level of the workplace to the lowest point of the upper horizontal element) of at least 1,200 mm with a solid side board along the bottom to a height of at least 100 mm. The fence must meet the requirements of GOST 12.4.059-89.

When the cargo is fed into the openings (hatches) through the inter-farm space or through several ceilings, when the openings (hatches) are located directly above each other, a shaft with smooth walls is equipped or the lowering of the load must be carried out with mandatory accompaniment. Examples of the supply of goods through openings (hatches) are presented on.

Delivery of goods into window openings and onto balconies without special receiving platforms or special devices is not allowed.

Buckets for special equipment BU

As a rule, the installation of internal plumbing systems is carried out in parallel with the installation of internal sewerage systems. This is due to the fact that they usually pass close to each other. Laying of water pipes should be carried out at temperatures above 2 degrees. For installation of pipes in rooms with high humidity, pipes with insulation are used that prevent metal corrosion and extend the service life of pipes for a longer time.

Sometimes air gets into the heating system.

Installation of heating systems for a house, cottage or any other building and structure is a critical part of the construction work, which follows after the complete construction of the box and the closing of the thermal circuit, but before the interior finishing of the premises. Good organization of the heating system is the key to further carefree operation of the facility. Incorrectly performed work will definitely lead to heating failures in general or individual devices.

Substation installation and works

Mark the wrong answer. Mark only incorrect answers. Mark only correct answers. Crane operators and slingers servicing jib-type cranes and pipe-laying cranes during work, such a list should be handed out.

The danger zone along the overhead power line, in which the danger of electric shock operates, is the space enclosed between vertical planes spaced from the extreme live wires at an appropriate distance. Construction and installation work using cranes in the security zone of an existing power transmission line with a voltage of more than 42 volts should be carried out under the direct supervision of the person responsible for the safe performance of work by cranes, with the written permission of the organization that owns the line and the work permit for the performance of work in hazardous areas. or harmful factors issued to the immediate supervisor of the work, and a work permit for the performance of work by a crane near an overhead power line, issued to the crane operator. When installing cranes in the security zone of an overhead power line, it is necessary to remove voltage from the overhead power line. If it is justified that it is impossible to remove voltage from the overhead power line, the work of construction machines in the security zone of the power line is allowed to be carried out provided that the following requirements are met: To perform work in areas of hazardous production factors, the occurrence of which is not related to the nature of the work performed, a work permit must be issued in accordance with the form. The work permit is issued to the immediate supervisor of the work, foreman, foreman, etc.

Using valves with thermal heads

These are the best taps that can only be put on radiators in the heating system of a private house. Adjusted to a certain air temperature, the thermal head acts on the valve stem, forcing it to open or close its flow area.Thus, there is an automatic quantitative regulation of the coolant passing through the heater.

The thermostatic valve is installed on the supply line to the battery, and a balancing valve is placed on the return line. It is a mistake to assume that the system will be automatically balanced by thermal heads; valves are needed in any case. The installation of conventional ball valves instead of them is allowed for centralized heating or in systems with a passing movement of the coolant (Tichelmann loop). But it is unacceptable to regulate the coolant flow using a ball valve, and it will not work.

Advice. Most models of thermal valves have a mode of mechanical blocking of the flow section. If you got products without such a mode, then you will have to install an additional cutter to service the battery, as shown in the diagram:

Recommendations for selection and installation

Models of air vents produced are equipped with elastic gaskets that provide a reliable and tight connection to the pipeline or radiators. Installing the air vent is not difficult, only an adjustable wrench is required from the tool.

If the gaskets do not provide tightness, you can use linen tow complete with putty, plumbing thread, it is undesirable to use FUM tape due to its low strength on sharp threads.

Automatic devices are installed vertically on straight, strictly horizontal pipelines; for manual air vents, a strict horizon is not so critical. When choosing and installing air vents, you can use the following recommendations:

• Manual air vents are installed only on heating radiators - in all other cases, airing is impossible to predict and it is more reliable to use automatic devices.
• You should not choose radiator modifications with rotating handles - small children can unscrew them and drain the coolant from the system, and if poisonous ethylene glycol is poured into it, the consequences can be catastrophic.
• You should refrain from purchasing Chinese automatic products - most budget models pass coolant along with air, jam during operation (the liquid does not have time to displace air). The internal parts of Chinese appliances are made of low-quality materials that are more prone to corrosion. At an affordable price, you can buy products of domestic and European manufacturers.
• It is better to install an automatic air vent along with a shut-off valve - this will allow you to dismantle the device at any time for replacement, maintenance or repair.

Rice. 11 How to install air vents in the manifold and hydraulic arrow

The air vent is a necessary element that ensures the efficient operation of the heating system when using radiator heat exchangers, numerous underfloor heating circuits. High-quality automatic models costing 3 - 5 USD. when installed at the right points, they completely exclude the possibility of airing the system without the third-party participation of the owners.

18. Installation of cranes

Documents of the Federal Service for Ecological, Technological and Nuclear Supervision. Documents on safety, supervisory and licensing activities in the field of supervision of lifting structures. The Collection includes the Rules for the Design and Safe Operation of Hoisting Cranes, approved by the Decree of the Gosgortekhnadzor of Russia No. Running Wheels. Load gripping bodies. Drums and blocks. Instruments and safety devices. Control devices.

Installation of a URAL trailer brake control valve - a list of parts and an M16x elbow of an air cylinder (JSC AZ URAL).

Crane manipulator, I load myself; I drive; "Teschina" hand - order, rent.General instructions for the production of works by cranes manipulators KAMAZ. Part 1. Cranes-manipulators can be allowed to move only those loads, the mass of which does not exceed their carrying capacity, taking into account the position of the outriggers. When operating a crane-manipulator, the requirements set forth in its passport and operating manual must not be violated.