Installation sequence of PVC drain pipe fittings: assembly process from pipe to fittings

PVC drainage system is the "blood vessel" of building drainage, and its installation quality directly affects the later drainage efficiency and use experience. Many people think that "receiving pipes" is a simple task, but ignoring the order and details often leads to problems such as water leakage and blockage. The following is the correct installation process for dismantling PVC drainage pipe fittings step by step from pipe treatment to accessory assembly.

The first is the preparation of tools and materials. Prepare steel tape measures, PVC special cutting knives, chamfers (or sandpaper), cleaning cloth, PVC adhesive (to match the pipe model), and required pipe fittings - such as tee, elbow, trap, pipe cap, etc. Note that the fitting specifications should be consistent with the pipe (for example, the pipe of De110 corresponds to the pipe of De110) to avoid the adaptation problem of "small pipe inserted into large pipe".

The next step is to measure and cut the pipe. According to the design drawings or the actual direction of the site, measure the required pipe length with a steel tape measure, and mark the cutting line with a marker on the pipe. When cutting, be sure to use a PVC special knife. The blade is close to the marking line and cuts vertically. Slowly rotate the pipe with even force to avoid skewed or burrs on the cutting surface. Skewed incisions can lead to weak bonding, and burrs may scratch the sealing ring or hinder drainage.

The third step is the pipe port treatment. There will be sharp burrs and uneven edges at both ends of the cut pipe, which must be polished with a chamfer or sandpaper: first grind the burrs on the inside of the nozzle (to avoid noise or hanging debris when water strikes), and then grind the outer edge (to prevent scratching the glue layer when inserting the pipe). Then use a cleaning cloth dipped in alcohol or water to wipe off the dust and oil on the port - any impurities will affect the stickiness of the adhesive.

The fourth step is the adhesive connection between the pipe and the pipe. This is the core step of installation, and the order cannot be messed up: first apply the adhesive evenly on the inside of the socket of the pipe (pay attention to coating the entire contact surface, do not miss coating), and then apply the outside of the socket of the pipe (the coating thickness should be the same, about 0.5-1 mm). After gluing, quickly insert the pipe into the pipe. When inserting, keep it straight, do not skew, and the insertion depth should reach the marking line of the pipe socket (usually 1/2-2/3 of the length of the pipe). After inserting, gently rotate the pipe 15-30 degrees (do not twist it back and forth), let the glue layer distribute evenly, and then keep it fixed for more than 30 seconds, and wait for the initial curing of the adhesive (it usually takes 24 hours to fully cure, and do not move the pipe during this period).

The fifth step is the installation of the fittings. Commonly used accessories such as traps should pay attention to the height of "water seal" - it is necessary to ensure that the height of the water in the trap is not less than 50mm (national standard), otherwise the odor of the sewer cannot be blocked; tee pipe fittings should be aligned in the direction of the drainage branch, such as the tee of the kitchen sink should be facing the drain pipe of the sink to avoid poor drainage due to reverse connection; the choice of elbow should be adjusted according to the space: use a 90-degree elbow when the space is sufficient (the drainage is smoother), and use a 45-degree elbow when the space is narrow (to reduce resistance).

The sixth step is to fix the pipeline. After the pipeline is installed, it should be fixed with a pipe card in time to avoid displacement due to self-weight or water flow impact. The fixing principle is: install a pipe card every 1 meter for the riser (vertical pipe), and one every 0.5 meters for the horizontal pipe (horizontal pipe); the pipe card should be fixed on the load-bearing structure of the wall or ceiling (such as concrete beam, keel), not fixed on soft materials such as gypsum board. Do not screw too tightly when fixing, leaving a little space for the pipeline to expand and contract.

Finally, the closed water test. After all pipes are installed, be sure to do the closed water test: plug the end of the pipe with a pipe cap or airbag, inject water into the pipe (the height covers at least the lowest interface), and let it stand for 24 hours. If the water level does not drop and there are no traces of water seepage at the interface, it means that the installation is qualified; if there is a water leak, it should be disassembled and reprocessed in time - do not wait for the tile to be pasted before finding the problem, otherwise the maintenance cost will be very high.

In fact, the installation of PVC drainage pipe fittings is not complicated, the key is to "come in order": prepare and then measure first, deal with the port first and then bond, install accessories first and then fix, and finally test. Every step is done in place to ensure that the drainage system is "unimpeded". Remember: slow work and meticulous work, take more time when installing, and worry a lot less later.