Semi-rigid flame-retardant plastic pipe concealed construction technology

1 Scope This process standard is applicable to electrical lighting concealed pipe wiring projects in general civil buildings, and shall not be laid in high-temperature places, places susceptible to mechanical damage, or in ceilings. ​

2 Construction preparation

2.1 Material requirements:

2.1.1 Semi-rigid plastic pipes and accessories must be made of flame-retardant materials. The outer wall of the plastic pipe should have continuous flame-retardant marks and manufacturer’s labels with a spacing of no more than 1m, and should have a product certificate. The thickness of the pipe wall is uniform, and there are no cracks, holes, bubbles, or deformation of the pipe body. Semi-rigid plastic pipes must not be stacked and stored in high temperatures or in open places. 2.1.2 Distribution box: It should be the product of two certified manufacturers, and the product should have a certificate of conformity. ​

2.1.3 Plastic boxes such as switch boxes, socket boxes, lamp holder boxes, and junction boxes should all have a neat appearance, complete knock-out holes, and no cracks or other phenomena. ​

2.1.4 Galvanized materials: flat steel, round steel, wood screws, machine screws, lead wire, etc. ​

2.1.5 Auxiliary materials: anticorrosive paint, adhesive, cement, sand, etc. ​

2.2 Main tools: 2.2.1 Pencil, tape measure, level, line weight, bucket, ash bucket, ash shovel. ​

2.2.2 Hand hammer, gouge, hacksaw, saw blade, knife saw, wood file, etc. ​

2.2.3 Bench drills, electric hand drills, drill bits, wood drill tool bags, tool boxes, high stools, etc. ​

2.3 Operating conditions:

2.3.1 Closely cooperate with civil construction, adjust the horizontal line and wall thickness line according to the building wall structure (such as brick wall, aerated brick wall, etc.), and install boxes, boxes and pipes. ​

2.3.2 When cooperating with the construction of civil structures, when constructing concrete walls with large formwork or sliding formwork, it is necessary to embed boxes and pipelines during the reinforcing bar binding process, and perform hidden inspections before proceeding with concrete pouring construction. ​

2.3.3 For air-entrained concrete floor slabs and round hole slabs, the pipes should be installed when the joints of the hoisted floor slabs are adjusted in time with the civil engineering. ​

3 Operation process

3.1 Process flow: Elastic wire positioning → Box box fixing → Pipe laying → Sweeping pipe threading line

3.2 Positioning of elastic lines: Measure horizontal lines and wall thickness lines according to the design drawings to determine the positions of boxes, boxes and embedded parts; boxes and boxes in rows should be straightened by hanging lines or cross lines to determine the positions of boxes and boxes. the exact location. 3.3 Boxes and precision fixing: 3.3.1 Boxes and boxes are firmly embedded in the block wall. Pick the holes according to the position of the box and box. The size of the hole should be slightly larger than the box and box. Clean the hole, wet it with water, and then bury the box and box firmly with cement mortar with a strength grade of not less than M10. If it is a hollow block wall, after digging holes, use crushed block cement mortar to seal the holes first, and then bury the boxes and boxes securely. 3.3.2 Cast-in-situ reinforced concrete walls, floor slab fixed boxes and boxes: 3.3.2.1 Use reinforcing steel boxes to be directly fixed on the steel bars. ​

3.3.2.2 Use machine screws to fix the boxes and boxes on the flat steel, and then fix the flat steel on the steel bars. ​

3.3.2.3 Prefabricated floor slabs with stably embedded lamp holder boxes: prefabricated round hole plates and aerated concrete floor slabs. The holes for the lamp holder boxes should be dug from bottom to top under the floor slab, and the upper holes can be expanded above the floor slab. Install the clamping iron or car pole on the box, install the ash board under the floor, wet the hole with water, and then bury the box firmly with cement mortar with a strength grade of not less than M10. ​

3.3.2.4 Sliding formwork concrete wall to securely bury boxes and boxes: Reserve boxes and box covers, then remove the boxes and box covers, and bury the boxes and boxes securely in the reserved holes. ​

3.4 Pipe laying: 3.4.1 Pipe laying requirements:

3.4.1.1 Semi-rigid plastic pipes can be connected by casing bonding. The length of the casing should not be less than three times the outer diameter of the pipe; the interface of the pipe should be located in the center of the casing, and the joint surfaces of the joints should be firmly bonded with adhesive. . ​

3.4.1.2 When laying pipes, bends should be minimized. When the length of the straight line section exceeds 15m or there are more than three right-angle bends, an intermediate junction box should be added. ​

3.4.1.3 Where the pipeline passes through the deformation joints of the building, there should be a compensation device that can move freely. ​

3.4.1.4 When grooving and laying pipes, horizontal grooves and laser cutting stainless steel bars are not allowed to be grooved; only grooving along the seams of the aerated concrete slab is allowed. ​

3.4.1.5 There should be no joints in the vertical pipe sections within the sliding formwork. ​

3.4.1.6 When the tubes are put into the box or box, the tube openings should be flush, and the tube openings exposed out of the box or box should not be larger than 5mm, and there should be one hole for each tube, and the hole size should match the outer diameter of the tube. ​

3.4.2 Pipe laying in block walls:

3.4.2.1 When building a wall, civil engineering should be coordinated. Semi-rigid plastic pipes should be laid in the wall. The pipe openings should be blocked when leading upwards, and temporary poles (steel bars or wooden poles, etc.) should be used to lift the pipes along the laying direction. In order to make the boxes and boxes flat and at an accurate height, the pipes can be laid to 100mm from the box and boxes and thrown out. After the wall is completed, the pipes can be inserted to bury the boxes and boxes securely. 3.4.2.2 When picking out the groove and laying the pipe, the thread should be played on both sides of the groove and picked with a quick chisel. For aerated concrete walls, use a knife saw to cut both sides and separate them. The groove width and depth should be 5mm larger than the outer diameter of the pipe. When laying the pipe, fix the pipe with iron nails and thin lead wire every 0.5m or so. Then use cement mortar with a strength grade of not less than M10 to protect the surface, and the thickness should not be less than 15mm. ​

3.4.3 Pipe laying on prefabricated floor slabs:

3.4.3.1 The pipelines laid on the prefabricated round hole plate should be tied with fine lead wires to the plate holes every 0.5m or so and within 0.15m from the lamp holder box, and then cement mortar should be used to bury the lamp holder box firmly. ​

3.4.3.2 The reserved pipe leading to the partition wall should not be too long, and the pipe opening should be blocked. ​

3.4.3.3 Pipe sections susceptible to mechanical damage should be protected with cement mortar in advance. ​

3.4.4 Pipe laying in existing concrete walls or floors:

3.4.4.1 The pipeline should be laid between the two layers of stainless steel bars. After the pipe is put into the box, the pipe opening and the box should be blocked. The pipelines should be tied firmly with thin lead wire and steel bars every 0.5m or so and within 0.15m from the box. ​

3.4.4.2 The reserved pipe leading to the partition wall should not be too long, and the pipe mouth should be blocked; the upward pipe can be lifted up with steel bars; the downward pipe can be reserved perpendicular to the partition wall (about 100mm× 50mm), or pre-embedded casing. After removing the formwork, lead the pipe down.

3.4.4.3 When constructing the sliding formwork, the pipe section from the switch box or junction box to the lamp position can be placed in the corbel wall section first. After the sliding formwork is completed, the pipe should be taken out in time and led to the lamp position after the top plate is supported. ​

3.5 Sweep the pipe threading line: 3.5.1 After the pipes are laid, and after the wall and floor construction is completed (the cast-in-place concrete project should be after the formwork is removed), the pipes should be pre-swept in time. During the pipe sweeping process, the pipeline must be checked against the construction drawings and faults in the pipeline must be dealt with in a timely manner. ​

3.5.2 When sweeping the pipe, use the method of sweeping the pipe with a cloth, that is, fix the cloth strip on one end of the pipe and pull it out from the other end of the pipe to remove debris and accumulated water in the pipe. After cleaning the pipe, the pipe mouth should be plugged and the box mouth should be closed. ​

4 Quality standards 4.1 Guarantee items: Semi-rigid plastic pipes must be made of flame-retardant materials, their oxygen index should be above 27%, and their materials and applicable locations must comply with design requirements and construction specifications. Inspection method: Observation and inspection or inspection of hidden engineering records. ​

4.2 Basic items:

4.2.1 The pipeline connections are tight, the pipe mouth is smooth, and the protective layer is greater than 15mm. Inspection method: observation and inspection, and inspection of hidden engineering records.

4.2.2 The boxes and boxes are set up correctly and fixed reliably. The pipes enter the boxes and boxes straightly, and the length exposed inside the boxes and boxes should be less than 5mm. Inspection method: observation, ruler inspection. ​

4.2.3 A compensation device should be installed where the pipeline passes through the deformation joint of the building, and the compensation device can move freely. Inspection methods: Observation and inspection and inspection of concealed engineering records. ​

4.3 Allowable deviation items: The allowable deviations for pipeline laying and box and box installation are shown in Table 3-4.

5 Finished product protection 5.1 When grooving and making holes, do not use excessive force to avoid breaking the surrounding wall surface. It is not easy to make the opening too large or too wide, so as not to cause civil structural defects. ​

5.2 Pipes should be protected immediately after being laid. When operating other types of work, care should be taken not to flatten or step on the pipes. ​

5.3 When making holes in concrete slabs and air-entrained slabs, be careful not to break the malleable steel bars. When making holes, drill holes first, and then expand the allowable deviations for pipeline laying and box and box installation. Table 3-4 Items Items Items Allowed Bonding test method 1 Tube’s minimum bending radius ≥6d meter inspection and check installation record 2 Tube’s curved flatness ≤0.1d ≤ 0.1d measurement 3