1. Assembly of the sleeve fitting
1.1 Pre-installation
The most important part of the pre-installation of the ① sleeve joint directly affects the reliability of the seal. Dedicated preheater are generally required. The tors with small diameter can be pre-installed on the pliers. Specific practice is to use a joint as the mother, the nut, the sleeve press to the pipe can. There are mainly card sleeve type through the pipe joint, card sleeve type end through the connection head, card sleeve type three-through pipe joint and other types. The author found that even if the same manufacturer is a batch of goods, the depth of the cone hole on these several joints is often not the same, resulting in leakage, and this problem is often ignored. The correct approach is to use what kind of joint body with one end of the pipe, the corresponding connection end with the same type of joint preloading, so as to avoid leakage to maximize the problem.
The end surface of the ② pipe shall be flush. After sawing, the pipe shall be polished flat on the grinding wheel and other tools, and removed from the burr, cleaned and blown clean with high-pressure air before use.
When ③ is pre-installed, the coaxiality of the pipe and the joint body should be kept as far as possible. If the pipe is too deviated, the seal will also cause failure.
④ pre-loading force should not be too ambassador the inner blade of the sleeve is just embedded in the outer wall of the pipe, the sleeve should not be significantly deformed. When connecting the lines, then assemble according to the specified tightening force.6-1 The tightening force of 64-1 15n, 16 фmmr 259n, and 18mm of the card sleeve is 450n. If the card sleeve is seriously deformed when pre-installed, it will lose its sealing effect.
1.2 No sealant. In order to achieve a better sealing effect, someone coated sealant on the jacket, the sealant was washed into the hydraulic system, causing the hydraulic element Yin hole blockage and other faults.
1.3 When connecting the pipe, the pipe shall have sufficient deformation allowance to avoid the tensile force on the pipe.
1.4 When connecting the pipeline, it should not be subjected to the lateral force, and the lateral force will cause lax sealing.
1.5 When connecting the pipeline, it should be good at one time to avoid multiple disassembly, otherwise the sealing performance will become worse.
Installation of sleeve pipe fitting
a. According to the requirements of the pipe should be pickling first;
b. Cut the pipe with sawing bed or special pipe cutting machine, absolutely do not use break (such as flame cutting) or grinding wheel cutting; remove the inner and outer round burr, metal chips and dirt; remove the rust agent and dirt of pipe joints; and ensure the roundness of the pipe;
c. Put the nut and sleeve into the pipe, the front edge (the trail end) is at least 3mm from the pipe orifice, and then insert the pipe into the cone hole in the joint, and the end to the top;
d. Tighten the nut slowly and turn the pipe until still, tighten the nut 2 / 3~4 / 3 laps;
e. Remove and check whether the sleeve has cut into the tube and in correct position. Card sleeve is not allowed to have an axial movement, can be slightly rotated;
f. Retighten the nut after qualified inspection.
2. Prevention of leakage at the pipe joints
In the hydraulic system, whether the metal pipe joints, or hose joints, there are easy to produce leakage problems. For the sleeve pipe joint, most of the pipe by a large external force or impact force, so that the sleeve loose or pipe end surface deformation caused by leakage, at this time should check whether the sleeve is not round, the blade mouth is defective, whether the pipe end is intact and the tightness of the sleeve nut, but also to eliminate the external force of the pipe. For the expansion pipe joint, most of them due to excessive expansion, quality is not required or multiple disassembly, resulting in expansion deformation or cracks caused by leakage, at this time, the front end can be cut off to expand again. If the female cone top pressure is used to seal, the leakage is mostly due to the damage to the two cone surfaces, and the cone surface can be ground with grinding sand. In some cases with "" ring end surface or outer diameter sealing, the leakage causes are the following: "" ring aging or deformation; "" ring assembly, uneven or "" ring cut leakage; "" ring not compacted, insufficient elastic deformation and leakage; "" ring stop groove too deep and leakage. In this regard, the "" ring with the same outer diameter and thicker section should be selected again, or the sealing plane with the stop groove can be cut or sharpened to reduce the depth of the stop groove, so that the "" ring has enough elastic deformation (the compression amount should generally be between 0.35-0.65mm). For the leakage of oil-resistant plywood, wool felt, soft steel cardboard, combined sealing gasket or sealant pipe joint, no matter what the material is, we should first check whether the seal is damaged for damage, deformation, aging and excessive roughness, and then take corresponding measures.
3. Notes for the installation of the high-pressure hose joint
(1) The hose should not bend excessively when moving or standing still, and it should not bend at the root, at least 1.5 times its diameter;
(2) When the hose moves to the extreme position, it should not be pulled too tight, and it should be relatively relaxed;
(3) Try to avoid the torsional deformation of the hose;
(4) The hose is as far away from the heat radiation components as possible, and the necessary fashion heat insulation plate;
(5) External damage to the hose should be avoided, such as long-term friction on the surface of the same component in use;
(6) If the weight of the hose causes excessive deformation, there should be supports.
4. Pre-installation of the pipeline
4.1. Introduction of the pipeline
(1) Double line supervisor and branch pipe: from the lubrication pump to the oil inlet of all distributors, the pressure is relatively high under pressure. Usually use cold pull seamless steel pipe, the material is 10 or 15 number steel. No badly corroded pipes must be used;
(2) Oil tubing: out from the distributor to all the lubrication point oil inlet (bearing seat oil hole), under a relatively low pressure. Usually use pull copper pipe, when bending easy pipe. There are also using cold-pull seamless steel pipe or stainless steel pipe;
(3) The hose joint is used when the active part is connected.
4.2. Pipeline layout requirements
(1) The pipeline should try to avoid the high temperature radiation and cooling water spray and other temperature is too high or too low, especially the hose joint;
(2) The pipe should not affect the operation of the host and other equipment, be safe and reliable, convenient for work, observation and maintenance;
(3) The pipe distribution should be horizontal and vertical, neat and beautiful. As far as possible less turning or small Angle bending pipe, using a large arc, so as to reduce the oil flow resistance;
(4) In case of installation conflict, large and low-pressure pipes for high-pressure pipes;
(5) The pipeline can not contact with each other, should be separated from a certain distance;
(6) The joints of parallel pipes should be staggered and installed, so as not to affect the installation and disassembly;
(7) For disassembly and cleaning, live joints should be installed, but should be used less to reduce the possibility of leakage.
4.3. Determine the length of the pipe
(1) According to the fixed pipe distribution path determined in Article 8.2, determine the length of the pipe on the site, and pay attention to the influence of the radius of the bending pipe;
(2) The impact of various pipe connections connected into the pipe should be taken into account;
(3) The length of the pipe should be determined, cut off and pre-installed section by section to facilitate the adjustment on the site according to the actual situation. If all the pipes are cut off at once, when there is an accumulated error, the pipe distribution is difficult;
(4) The cut short pipe should be used as far as possible in each place where the short pipe is needed. If necessary, the direct pipe joint can be used for the long connection, but the joint on the pipe section should not be more.
4.4. Pipe cutting
(1) Cut off the pipe with a saw bed or a special pipe cutting machine and other machines, and absolutely do not allow the dissolution of cutting (such as flame cutting) or grinding wheel cutting;
(2) The incision should be flat, the plane of the section should not be more than 1 mm, and the perpendiculality with the pipe axis should not be more than 1 degree;
(3) Remove chips and burrs with a file and scraper;
(4) Use clean compressed air or other methods to remove the attached debris and floating rust in the pipe;
4.5. Pipe bending
(1) With the bending machine cold bending, not hot bending (large diameter pipe can be replaced by right-angle joint bending pipe), the bending radius should be more than 4 times the diameter of the pipe;
(2) The ellipticity (length and length diameter change) at the bend is less than 10% of the pipe diameter, and the wrinkle can not occur;
(3) If there is a joint at the end of the pipe, a straight pipe should be connected to the joint to avoid affecting the installation
4.6. Pipe and joint welding
(1) Using tungsten pole argon arc welding or argon arc welding bottom sealing after arc welding filling welding. When the pressure exceeds 21mpa, 5l / min argon shall be supplied inside the pipe;
(2) When the pipe wall thickness is greater than 2mm, the outer circle should be cut into 35° slope, and leave 3mm gap at the counterpart; when the pipe wall thickness is 2mm, do not cut the slope and 2mm gap at the opposite place;
(3) The axis of the pipe must coincide, the wrong edge amount is less than 15% of the wall thickness, and the bias slope is less than 1:200;
4.7. Installation of pipe clips
(1) The pad plate of the pipe clip is generally welded in the structural parts directly or through corner steel and other supports, and the support is fixed on the concrete floor surface or wall side with expansion bolts;
(2) Attention should be paid to leveling when the pipe clip installation, that is, the installation surface is at the same height;
(3) Spacing between pipe clips: about 0.5~1 m at 10 pipe diameter; about 1~1.5 m at 10~25 pipe diameter; about 1.5~2 m at 25~50 pipe diameter, but at the right corner, one pipe clip should be used on both sides.
4.8. Pre-installation
(1) Connect the pipe joint with the equipment, pipe and pipe joint step by section until all the pre-installation is completed;
(2) See Chapter 4 for the installation method of pipe joints;
(3) At the same time, weld the pipe clamp plate on the structural parts or bracket, and do not weld the pipe on the pipe clip or bracket;
(4) After the pre-installation and qualified inspection, print the pipeline with a mark, one by one, and be listed as a form for backup. After the pipe is removed and cleaned, restore according to the number.
4.9. Notes
(1) Before installation, all steel pipes can be pickling treatment according to the requirements of Chapter 9, especially the steel pipe connected with the sleeve pipe joint should be pickling first, and then the sleeve should be fastened at the pipe end in advance;
(2) All pipe joints should be cleaned with kerosene to be installed first, and the o-type sealing ring inside should be removed temporarily for storage, and then put on for formal installation;
(3) During the construction, the oil outlet of the pump, distributor and other equipment, pipe joints and pipe ends should be kept clean, and water, dust and other foreign bodies should not be allowed to enter;
(4) The pipeline shall be laid in a free state, and the welded pipeline shall not be forcibly fixed and connected with too large radial force;
(5) The oil hole of the bearing seat should be checked in advance, whether the internal oil circuit is smooth, and whether the oil outlet thread is matched with the joint.
6. Pipeline cleaning and editor broadcast
To ensure a clean lubrication system and to supply the mechanical equipment bearings for clean grease, the pre-installed lines must be removed and cleaned. Cleaning has kerosene cleaning and pickling two kinds.
6.1. Kerosene cleaning object and method
(1) Copper pipe, stainless steel pipe;
(2) Steel pipes that have been pickling before pre-installation and the inner wall is not rust-free;
(3) Dirty pipe joints during pre-installation;
(4) Remove the pipe and joints to be cleaned, the tube with cloth (or hair yarn) with kerosene to clean the tube, both ends and joints soaked in kerosene cleaning, and then coated in the tube with oil or filled with grease, both ends closed to install;
(5) After cleaning, there shall be no visually visible pollutants (such as iron chips, fibrous impurities, welding slag, etc.), and special attention should be paid to the welding slag in the welding wall that must be thoroughly cleaned.
6.2. Surge the object
(1) Unpickling steel pipe before pre-installation;
(2) Although the steel pipe has been pickling, but seriously corroded steel pipe.
6.3. pickling construction sequence and treatment purpose
(1) Use skim agent to remove the adhesive oil on the pipe;
(2) Wash water with clean water to remove the dirt on the pipe;
(3) Rust removal Remove the rust spots and rolled iron chips on the pipe wall in the pickling liquid;
(4) Washing and high pressure water rinse the attachments produced in the above operation with clean water, and rinse the interior of the pipe with high pressure water;
(5) The residual acid liquid on the pipe;
(6) Dry In order to effectively dry the pipe should be immersed in hot water or steam drying, the pipe should be dry thoroughly;
(7) Anti-rust;
(8) Check whether the pickling pipe is cleaned;
(9) After packaging and keeping the pickling, immediately seal the opening of the pipe with plastic or plastic belt, to avoid the invasion of foreign bodies and water.
6.4. Notes for pickling
(1) The welding operation of the pipe before pickling has all been completed;
(2) When disassembly, transportation and pickling, do not touch the pipe, thread and sealing surface, and block the seal with adhesive tape or plastic pipe;
(3) Before pickling, the welding slag, splash out and varnish on the pipe should be removed;
(4) Each thread part shall be protected by plastic belt, rubber belt and other acid-resistant materials, or coated with dry oil at the thread after degrease and washing, and then remove rust in the acid solution to prevent erosion by the acid solution;
(5) Pay attention not to make the disappearance or mark of the pipe blurred during pickling.
6. The pipeline is officially installed to edit and broadcast
The cleaned lines shall be formally installed and filled with fat as soon as possible
(1) Connect all pipelines section by section according to the printed matching mark;
(2) Tighten all pipe joints according to the method of Chapter 4, and pay attention to put the original removed o-ring;
(3) All piping should be firmly fixed and not loose;
(4) All oil pipes can be left to be filled and then connected with the oil outlet and lubrication point of the distributor.
