Installation method: construction and installation method
1, general requirements
(1) Installers should be familiar with the general performance of hot-melt plug-in PP-R (random polypropylene) pipes and master the basic operation points.
(2) The installer should be familiar with the design drawings and understand the structural layout of the building and its relationship with other types of work.
(3) Before construction, the materials, appearance and accessories shall be inspected, and it is forbidden to expose crosslinked polypropylene pipes to the sun for a long time.
(4) Casing shall be set at the place where the pipeline passes through the wall and plate, and the inner diameter of the casing shall be 20mm larger than the outer diameter of the pipeline, and the casing shall be filled with flexible incombustible materials.
(5) When the pipeline is buried underground or in a wall or plate, the water pressure test must be carried out first, and it can be buried or closed only after it is qualified.
2, piping points
(1) The pipe shall be cut with special scissors or ordinary hand saw. When cutting the pipe, the incision should be smooth. When shearing, the section should be perpendicular to the pipeline axis.
(2) Scrape an inclined plane on the outer surface of the pipe end. Before welding, it is best to clean the welding parts with alcohol and then dry them with clean cloth or paper. And draw the length to be welded on the pipe.
(3) Open the special welding machine and heat it to 260℃. When the control indicator light turns green, start welding.
(4) Put the pipes and pipe fittings to be connected into the welding head, and heat the outer surface of the pipes and the inner surface of the pipe fittings. Then, pull it out of the machine head at the same time, and quickly insert the heated end of the pipe into the heated fitting interface. Do not rotate the test tube when inserting, and let it cool for a few minutes after inserting. Heating time, cooling time and welding depth shall be as follows:
Outside diameter of pipeline (mm) welding depth (mm) heating time (s) treatment time (s) cooling time (min)
20 14 5 4 3
25 16 7 4 3
32 20 8 4 4
40 2 1 12 6 4
50 22.5 18 6 5
63 24 24 6 6
75 26 30 10 8
90 32 40 15 8
1 10 38.5 50 10 10
Note: If the ambient temperature is lower than 5℃, the heating time should be extended by 50%.
(5) After the welder is used, the nose must be cleaned for the next use.
(6) Install the welded pipeline in place.
3, pipe, hanger installation
(1) The selection of pipe supports and hangers can be based on the site installation conditions, such as plastic pipe clips made by pipe manufacturers or steel supports and hangers on pages 55-16/kloc-0, 48 and 49 of the national general water supply and drainage standard atlas. During installation, a layer of soft rubber sheet with a thickness of 1mm shall be placed between the pipe clamp and the pipe of the steel hanger.
(2) Installation spacing of pipe supports and hangers
1) The maximum spacing of riser supports is as follows:
Outside diameter of pipeline (mm) 20 25 32 40 50 63 75 90110
Maximum spacing (mm)10001200150017001800 2000 2100 2500.
2) The maximum spacing between supports and hangers of horizontal pipelines is as follows:
Outside diameter of pipeline (mm) 20 25 32 40 50 63 75 90110
Maximum spacing (mm) 650 800 9501001250140015001900.
(3) System hydrostatic test
1, the hydraulic strength test pressure should be 1.5 times of the working pressure of the pipeline system, but not less than 0.60MPa, and the pressure test value adopted in this project is 1.00MPa.
2. Before the water pressure test, take safe and effective fixing and protection measures for the pressure test pipeline.
3, water pressure test steps
(1) Block the end of the pressure test pipeline, inject water slowly, and remove the gas in the pipeline at the same time.
(2) Check the water tightness after filling with water.
(3) The system shall slowly boost the pressure, and the boosting time shall not be less than 10 minute.
(4) After boosting to the specified test pressure, stop boosting and stabilize the pressure for 65438+/-0h, and observe whether the joint leaks.
(5) After stabilizing the pressure 1h, the pressure shall be supplemented to the specified test pressure value to eliminate the interference of the volume expansion of the pipeline on the test results after the pipeline is compressed due to water load.
Construction Requirements for Indoor Buried Pipe Laying of Water Supply Polypropylene Pipe (рр-R) (Hot Melt)
First, the process flow:
Construction preparation → trench excavation → drawing installation details → underground pipeline laying → pressure test → backfill soil and setting protective pipes → quality inspection records.
Second, the requirements:
A the following conditions shall be met before pipeline installation and construction:
1. Technical documents such as construction drawings are complete, and technical disclosure of drawings has been made to meet the construction requirements.
2. The construction scheme, construction technology, materials and machinery supply can ensure normal construction.
3. The construction personnel shall receive technical training for the installation of polypropylene pipes for building water supply.
4. The pipes and fittings provided shall meet the design requirements, with product specifications and quality certificates. Materials with signs of damage shall not be used. After the materials enter the site, check the specifications and quantity. Check whether the pipeline is flat or cracked, and find the manufacturer to replace it in time.
5. Handle pipes and fittings with care to avoid oil pollution. Pipes and fittings should be stored in a well-ventilated warehouse or simple shed, not in the open air, to prevent direct sunlight, and pay attention to fire prevention. Pipes shall be stacked horizontally on a flat ground, and the stacking height shall not exceed1.5m. ..
B the pipeline shall be laid in the compacted fill layer. After the compacted fill layer is compacted, the excavation shall be carried out according to the buried depth of the pipeline. It is forbidden to lay pipelines before backfilling or in uncompacted soil layer, and the trench bottom for laying pipelines should be flat. There shall be no protruding hard objects. The particle size of soil should not be greater than 12mm, and a sand cushion with a thickness of 100mm can be laid when necessary.
C. Pipes below 0.00 for indoor floor shall be laid at both ends. Pipes below 0.00 shall be laid to the outer wall section of foundation wall first, and outdoor connecting pipes shall be laid after the completion of civil construction.
D before laying the pipeline, draw the sample drawing according to the position of the design drawing and measure the actual length. If there is any change in site construction, graphic records shall be kept.
E hot melt connection should be adopted between water supply polypropylene pipe and pipe fittings of the same material, and special hot melt tools should be used during installation. Threaded connection and flange connection shall not be used for buried pipelines. Polypropylene welded pipes for water supply shall be connected by metal fittings, and polypropylene fittings with metal inserts shall be used for transition. The pipe fittings are connected with plastic pipes by hot melt, and connected with metal pipe fittings or sanitary ware hardware by thread. Hot melt connection shall be carried out according to the following steps:
1. The hot-melt tool can only be operated when the power supply is connected and the working temperature indicator light is on;
2. When cutting the pipeline, the end face must be perpendicular to the pipeline axis. Pipe shears or pipe cutters are generally used for pipe cutting, and sharp hacksaws can be used if necessary, but burrs and burrs on the cross section of the pipe should be removed after cutting;
3. The connecting end faces of pipes and fittings must be clean, dry and oil-free;
4. Measure and draw the hot melt depth of the pipe end with a caliper and a suitable pen. The hot melt depth shall meet the following table:
Technical requirements of hot melt connection
Nominal outside diameter (mm) Hot melt depth mm Heating time (s) Processing time (s) Cooling time (min)
20 14 5 4 3
25 16 7 4 3
32 20 8 4 4
40 2 1 12 6 4
50 22.5 18 6 5
63 24 24 6 6
75 26 30 10 8
90 32 40 10 8
1 10 38.5 50 15 10
Note: If the operating environment temperature is lower than 5℃, the heating temperature should be extended by half.
5. When hot-melting elbow or tee, pay attention to its direction according to the requirements of design drawings, and mark its position with auxiliary signs in the straight direction of pipe fittings and pipelines;
6. When connecting, guide the pipe end into the heating jacket without rotating and insert it to the marked depth. At the same time, push the pipe fitting onto the heating head, without rotating, to reach the specified mark, and the heating time must meet the provisions in the above table (or according to the provisions of the hot melt tool manufacturer).
7. Immediately after reaching the heating time, remove the pipes and fittings from the heating jacket and the heating head at the same time, and quickly insert them into the marked depth along a straight line without rotating, so as to form a uniform flange at the joint.
8. Within the processing time specified in the above table, the newly welded joint can be corrected, but rotation is prohibited.
F pressure test shall be carried out before the trench returns to the soil, and the civil work can continue only after the pressure test meets the requirements. (The test pressure shall be 1.5 times of the working pressure of the pipeline system, but not less than 1.0 MPa). Pipeline hydrostatic test shall meet the following requirements:
1. For hot-melt connecting pipes, the water pressure test time should be 24 days later.
2. Before the hydrostatic test, the pipeline should be fixed and the joint should be exposed.
3. After the pipeline is filled with water, exhaust the air in the pipeline first and check the water tightness.
4. The hand pump should be used for pressurization, and the pressurization time should be no less than 65438±00min, and the pressure accuracy of the measuring instrument should be 0.065438±0 MPa.
5. To the specified test pressure, stabilize the voltage for 65438 0 h, and the test pressure drop shall not exceed 0.06Mpa.
6. When the working pressure is 1. 15 times, stabilize the pressure for 2 hours, and the pressure drop shall not exceed 0.03Mpa. At the same time, check whether there is any leakage at each joint. Within 30 minutes, it is allowed to make up the pressure twice and raise it to the specified test pressure, and fill in the Record of Strength and Tightness Test of Pipeline System, and carry out cleaning test before the pipeline is completed and put into use, and fill in the Record of Cleaning (Purging and Degreasing) of Pipeline and System. The evaluation of this work must be completed after the pressure test and before the concealed work. At the same time, fill in the "Acceptance Record of Pipeline Concealed Works" in JZ 17-4.
G. Only after passing the pressure test can the pipeline be returned to the landfill. The backfill around the pipeline shall not be mixed with hard objects and shall not be in direct contact with the pipe wall. Backfill with sand or soil with particle size not greater than 12mm to 300mm above the top of the pipe. Backfill can be carried out only after the original soil is compacted. The buried depth of indoor buried pipes should not be less than 300mm, and the place where the pipes leave the ground should be protected, and its height (PVC-U sleeve) should be higher than the ground. When the pipeline crosses the foundation wall, a metal sleeve should be set. When there is no provision in the design, the clearance height between the sleeve and the reserved hole of the foundation wall should not be less than100 mm.
H. quality control points:
1. It is forbidden to lay in the soil before backfilling or in the uncompacted soil layer, and the trench bottom for laying pipelines should be flat.
2. Hydrostatic test must be conducted before backfilling.
3. Backfill soil shall be backfilled with sand or soil with a particle size not greater than 12mm to 300mm above the pipe top.
4. The pipeline shall be installed on the ground.
5. Hot melting must be carried out in accordance with relevant requirements.
Third, the main machines and tools:
Name specification remarks Name specification remarks
Cutting machine wrench
monkey wrench
Hacksaw steel tape measure
Hot melt shovel
Caliper pick
Four, operating conditions:
1. The indoor pipelines laid underground shall be excavated again after the civil backfill soil is compacted.
2. Before construction, the design drawings and technical documents are complete, qualified materials and machines are in place, and there is a well-ventilated warehouse.