Quality problems in water supply and drainage and heating engineering construction of 1
1. 1 Water supply and drainage and heating pipeline installation quality problems
1. 1. 1 No measures were taken when the pipeline passed through expansion joints, seismic joints and settlement joints.
This problem is implemented according to the requirements of Article 3.3.4 in GB50242-2002, and both sides of the wall are connected flexibly. Install a square compensator horizontally on the wall; There shall be a gap of not less than 150mm above and below the pipeline or insulation layer.
1. 1.2 casing installation is not in place.
(1) Article 3.3 of GB 50242-2002.13 has specific requirements on the installation and setting height of sleeves, which should be strictly observed in the actual engineering construction process: when installing sleeves in toilets and kitchens, the top of sleeves should be 50 mm higher than the decorative floor, and the bottom of sleeves should be flush with the bottom of the floor. When installing the bushing in the floor, the top of the bushing should be 20 mm higher than the decorative floor. When installing the sleeve on the wall, both ends of the sleeve should be flush with the decorative surface. The following measures should be taken for the gap between casing and pipeline: the gap between pipeline and wall-penetrating casing should be filled with flame-retardant dense materials, and the end face should be smooth. The gap between the pipeline and the floor bushing should be filled with flame retardant dense materials and waterproof ointment, and the end face should be smooth.
(2) Requirements for setting sleeves: In order to facilitate future use and maintenance, water supply and drainage, fire fighting, heating and other pipelines should be set in the pipelines passing through walls and floors.
1. 1.3 pipeline insulation is often neglected.
Article 4.8.22 in GB500 19-2003 clearly points out that heating pipes should be insulated under any of the following circumstances: the pipes should be laid in ditches, technical interlayers, closed roofs and tube wells or places prone to freezing; The room or place where the pipeline passes needs thermal insulation; The useless heat loss of the pipeline is large, and the heat medium transported in the pipeline must keep certain parameters. According to the requirements of Article 3.5.25 of GB500 15-2003, anti-freezing measures should be taken for water supply pipelines laid in rooms, basements, tube wells, pipe trenches and other places where ice may be formed. However, in the actual construction process, due to the negligence or misjudgment of designers or constructors, it often happens that pipes in non-heating stairwells, semi-basements, tube wells, water tanks and other places are not treated with heat preservation and antifreeze. In cold season, the pipeline will freeze and crack because of low temperature, which will cause heat loss of heating pipeline on the one hand and a lot of maintenance costs on the other.
1.2 installation quality of water supply system;
1.2. 1 The pipeline installation is not standardized, resulting in poor support firmness. Problems such as pipeline leakage, bending, deformation and fracture often occur in construction projects. On the one hand, PPR pipes with poor rigidity are mostly used for drainage pipelines at present. On the other hand, the construction workers did not follow the specifications during installation, which led to unstable installation between them, leaving future troubles. Therefore, in the process of water supply and drainage installation, brackets should be installed in strict accordance with the construction technology, and the bracket spacing should be set according to the specification requirements.
1.2.2 At present, when the building is completed, most of them are rough houses, and the construction unit generally only carries out the decoration of rough houses in the building. After the water supply pipe is installed on the bathroom wall, the pipe is very close to the wall, which brings a lot of inconvenience to the householder's later decoration. Because the gap between the water supply pipe and the wall is too small, it is still difficult to install the water meter, not to mention the difficulty of redecorating after installing the water meter. If the construction team follows the requirements of Article 4.2. 10 in GB50242-2002: during installation, ensure that there is a clear distance of 10 ~ 30 mm between the water meter shell and the decorative surface after installation, such problems can be completely avoided.
1.2.3 the state expressly stipulates that cast iron faucets and sand cast iron pipes are obsolete products in construction and are prohibited from being used in construction. However, in the actual construction, it is found that some houses are still using such products, which brings a lot of inconvenience to residents' future life.
1.2.4 Before the water supply system is completed and put into use, the clean water source of the water supply pipeline should be pressurized and flushed at a flow rate not less than 1.5m/s to ensure that the dirt in the pipeline is completely washed away. If the tap water in the building is turbid, it is mostly caused by the construction party not flushing the water supply pipeline or the flushing is not in place.
1.2.5 Who should be strictly disinfected according to the construction specifications? After inspection by relevant departments, an inspection report will be issued. The specification points out that the water supply system should be disinfected with clean water with chloride ion concentration of 20 ~ 30 mg/L at first, and the chlorine solution in the water supply pipeline should be kept for at least 24 hours, and then the pipeline should be cleaned with residents' drinking water. In construction, the problem of inadequate disinfection of water supply system often occurs.
1.2.6 Pipeline leakage often occurs during construction. According to the requirements of construction technology, the pipeline interface should be tight, and the tightness of the pipeline should be carefully checked. The pipeline must be subjected to water pressure test according to the design requirements and construction specifications, and it can be concealed only after it is qualified.
1.3 installation quality of drainage system;
1.3. 1 Fabrication and installation of drainage pipe piers, supports and hangers.
(1) Cement mortar shall be applied to outdoor corners and tees of drainage pipes. Some construction workers set up hollow brick or dry brick piers here, which can't withstand long-term pipeline pressure. (2) The pier at the bottom corner of the neutral pipe in the drainage pipeline is prone to loose support. (3) Before cutting and punching the support, the construction site was not measured in advance, and the cutting position and punching position were certified and calculated, which led to blind cutting and punching, which made the installation difficult, and more waste holes affected the use of the support. (4) Brackets and pipes shall be made of the same material. If they are different, rubber asbestos shingles are not used for joint isolation as required. (5) The metal supports and hangers of drainage pipes are directly processed and installed without rust removal and rust prevention, which will greatly shorten the service life of the supports.
1.3.2 pipeline installation
Drainage pipe installation
(1) When the drainage pipeline passes through the basement or the external wall of the underground building, the construction unit fails to make waterproof casing as required by the design drawings, or even if waterproof casing is made, the height or position of the casing is not up to standard during installation, and it still cannot play a waterproof role. (2) When drainage pipes pass through seismic joints, structural expansion joints and settlement joints, seismic and settlement protection treatment is neglected. (3) The pipe thread is broken, the pipe thread is exposed for too long, and the control pipe thread 2-3 is not exposed according to the specification requirements. (4) When the pipeline passes through the floor and heating wall, the casing is not set or the setting is not standardized. (5) The gap between the casing and the pipeline is not filled with flame retardant material, resulting in different width of the thin gap.
1.3.3 sanitary ware installation
(1) The traps of sanitary ware such as washbasin and laboratory basin are installed under the floor, which brings inconvenience to future maintenance.
(2) The position of sanitary ware drain is not strictly controlled as required.
(3) The bracket installation of sanitary ware is uneven or unstable. The contact surface is uneven and the gap is large.
(4) The mortar at the joint between the bathroom and the ground is uneven, and the flexible pad is not assumed in the bathroom bolt, which leads to the instability of the bathroom.
(5) The flush pipe angle of the squatting pan is incorrect, and two 14# copper wires are not used to stagger and bind the rubber bowl at the water inlet.
(6) Low water tank leaks
(7) No sanitary ware nozzles and valves are installed. According to the instructions.
1.4 installation quality of heating system;
1.4. 1 The slope and direction of the heating pipeline are not up to standard. The hole position of the pipeline should be accurately reserved and installed in strict accordance with the slope, position and direction required by the drawing design. Some builders do not recommend using the bracket as a pedal after installation.
1.4.2 The radiator is unevenly installed and its position is incorrect. Radiators can be installed after the floor decoration is completed or the decoupling reaches the specified strength, but not too many radiators can be installed. Before installing the unhooking and fixing clip, the cable should be pulled in advance.
1.4.3 radiator is not installed firmly, and it is loose after installation. When installing unhooking, fixing clips and brackets, the construction technology shall be strictly installed, and the radiator shall not be trampled.
1.4.4 The radiator is hot or cold. Before installation, it is necessary to ensure that the dirt in the radiator has been thoroughly cleaned, and the radiator should also be cleaned and discharged when used to prevent the dirt from blocking and affecting heat dissipation.
1.4.5 The radiator interface drips during use. Pressure test should be carried out before heating, and the pipeline should be tested in strict accordance with the prescribed procedures, and the responsibility lies with people. If leakage occurs, it should be marked and handled in time. Strictly in case of non-compliance inspection, use the pointer to swing in a straight line as the acceptance data.
1.4.6 There are welding problems in galvanized pipeline. Article 4. 1.3 in GB50242-2002 clearly points out that galvanized steel pipes with a diameter less than or equal to 100mm should be connected by threads, and the damaged galvanized surface and exposed threaded parts during threading should be treated with anti-corrosion; Galvanized steel pipes with a pipe diameter greater than 100mm should be connected by card flanges or special fittings, and the welded joints between galvanized steel pipes and flanges should be galvanized twice. At present, the heating system with household metering is adopted, and some pipes use galvanized welded pipes with diameters greater than 32mm, which is easy to cause leakage. Construction personnel should strengthen the study of quality standards and master the engineering quality.
1.4.7 adopts household metering heating system, and there are many buried pipes, but most heating pipes use PPR pipes, and pipe joints are inevitable. This is inconsistent with the requirement in the Code for Design of Heating, Ventilation and Air Conditioning that plastic sleeves should be added outside buried pipelines and there should be no joints.
1.4.8 quality problems in the construction of floor radiant heating system;
(1) In the radiant floor heating system, there is a high requirement for laying insulation boards. When laying multi-layer insulation boards, whether multi-layer or single-layer, attention should be paid to staggered joints, and the joints between boards should be pasted with special tape paper. In some construction projects, the joints are not treated at all, and only the insulation boards are placed according to their positions, which can not play the proper insulation role at all, and will also cause heat loss.
(2) Bushing must be set in densely populated areas such as doorways and corridors due to excessive heat, and flexible bushing should be used when the pipe spacing is100 mm. If casing is not set in densely populated areas of heating pipes during construction, the service life of pipes will be shortened and troubles will be brought in the future.
Prevention measures of water supply and drainage and heating engineering quality problems in building engineering.
Many factors will lead to quality problems in building heating and water supply and drainage projects, such as low quality of technicians, limited technical level, lax quality control of building materials, improper connection of various processes, and imperfect engineering supervision and management mechanism. In view of various problems existing in the construction of building heating and water supply and drainage engineering, we must pay enough attention to it and strictly control the technology and quality. Appropriate measures should be taken in time to remedy the problems that have occurred.
2. 1 Prevention and control of construction quality before construction of building heating and water supply and drainage works
2. 1. 1 Carefully review the design drawings and other relevant construction materials provided by the design institute, and timely feed back the technical loopholes in the drawings to the relevant departments for thorough solution. After getting the construction contract, first of all, after the joint review of drawings, the pipeline direction of water supply and drainage and heating engineering is initially located. Familiar with construction codes and standards, and strictly follow these codes in future work.
2. 1.2 Improve the construction organization design. On the basis of project planning, construction organization design is to formulate feasible technical, organizational and management schemes in strict accordance with the requirements of construction drawings and the actual situation of the project. It is a guiding document in the whole construction process, which has certain legal effect and is a feasible management rule for the smooth implementation of the project.
2. 1.3 Seriously prepare for the construction. Construction technicians must hold relevant certificates according to regulations. Welding and lifting equipment must undergo strict safety training and on-the-job training for special jobs. Various instruments and tools used in the construction process should be checked regularly to ensure that the equipment integrity rate reaches 100% in the construction process, so as to ensure the safety and smooth progress of the whole project.
2. 1.4 Technical disclosure and safety disclosure shall be done before construction. Through technical disclosure, construction workers can have a preliminary understanding of the important links of the project and pay enough attention to them, and introduce the problems and solutions encountered in the blue prints.the design to construction workers in the disclosure, so as to help them make technical adjustments. In addition, it can also alleviate the conflicts in the convergence of various majors to varying degrees. Through technical disclosure, the construction party can make clear the construction intention, such as whether the layout of drainage pipes and heating pipes in bathrooms and kitchens needs to be unified, and what are the requirements for material selection levels. Through safety disclosure, the construction party can improve safety awareness, and at the same time clarify safety responsibilities to ensure the smooth progress of the project.
2. 1.5 Do a good job in site management. Should actively keep in touch with the project supervision, timely grasp the progress of the project and the problems existing in the project, and make reasonable solutions. Formulate the site management system, master the acceptance criteria, and do a good job of communication with the construction unit.
2.2 Quality control in the construction process
2.2. 1 Quality control of good materials entering the site. It is necessary to ensure that all building materials cannot enter the site without the material certificate and material inspection report of the national quality supervision department. Heating, water supply and drainage materials should also strictly implement the acceptance system. In addition, if it is technically required that materials that should be inspected twice before construction must pass the second inspection before use.
2.2.2 In the process of construction, the position, direction, elevation and slope of various pipelines shall be controlled in strict accordance with the technical requirements. The fewer turns the pipe has, the better. The pipeline setting is mainly horizontal, and the drainage pipeline cannot be reversed. Try to avoid bending up and down with other professional pipelines during pipeline construction. The fixing bracket must be firm. The spacing and position of supports shall be calculated accurately.
2.2.3 The pipeline should be carefully checked before it is concealed. Establish a strict supervision and management system and make inspection records in the inspection work. Unqualified pipes shall not be concealed, and must be thoroughly rectified under the guidance of professional and technical personnel, and can only be concealed after passing the inspection again. Pipeline inspection of high-rise buildings is relatively complicated, and buildings can be divided into three different batches: high, medium and low.
2.2.4 Arrange each working procedure reasonably and check the completed project in time. The on-site supervision system should be strictly implemented for the key working procedures and key parts of the project, and the process progress should be strictly checked. Investigate quality hidden dangers in time. Problems should be dealt with in time. Minimize losses.
Through the above research on building water supply and drainage and heating engineering, drainage pipe installation, heating construction and other issues, some solutions are put forward, hoping to provide reference for people engaged in water supply and drainage and heating engineering, help the practical work in the future, and further improve the quality of building engineering.
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