1, different pipe laying forms have different requirements for some pipe fittings.
There are three ways to install the horizontal drainage branch pipe: ① the pipe is suspended under the floor of this floor, which is also called "non-floor drainage" or "suspended drainage under the floor"; (2) The ground structure of the toilet sinks, and the pipeline is laid on the backfill layer, which is also called "sinking drainage on the same floor"; ③ The pipeline is installed on this floor, which can also be called "drainage on the same floor". Generally, the first and second forms are selected for laying drainage pipes in bathrooms, and the first and third forms can be selected for kitchens. Different pipe laying forms lead to different arrangements of the following pipe fittings.
The setting of 1 1 casing
According to the specification, the pipeline should pass through the wall and floor, and be provided with metal or plastic sleeves. The height of the sleeve installed in the kitchen and bathroom is required to be 50mm higher than the decorative floor. Both ends of the sleeve installed in the wall are flush with the finish. For suspended drainage under the floor, there should be no problem in implementing this requirement. But you can't install sinking drainage casing on the same floor, and you can only do waterproof treatment. The waterproof layer should be below the horizontal branch pipe, and the riser should extend out of the molding ground. Waterproof ointment can be embedded in the root of the pipeline to make a cement mortar waterproof ring with a height of 50mm and a width of 30 mm. At the same time, it is required to waterproof the surface layer, otherwise the sinking structure will become a puddle, which will destroy the building and environmental sanitation. For the drainage on the same floor, it should be noted that if the riser is outdoors, the part of the wall bushing near the outdoor should be waterproof and padded, and the water stop ring or plastering and external wall should be decorated accordingly.
1.2 setting of expansion joints
Plastic drainage pipes of residential buildings should be equipped with expansion joints according to design requirements, generally one on each floor, and expansion joints should be set at confluence fittings. Therefore, the expansion joint of the suspended drainage pipe under the floor is located below the pipe fittings such as tee or cross, and the distance from the confluence pipe fittings is 7~ 10cm. The expansion joints of the same floor sink drain pipe and the same floor ground drain pipe are located 7~ 10cm above the confluence pipe fittings. If it is in the backfill layer, the expansion joint can be located at a distance of 15~20cm from the decorative floor. Or when a branch pipe is close to the floor in the same floor, the expansion joint can be arranged in the middle of the pipe. The setting of expansion joint of horizontal horizontal pipe should also meet the design requirements, and more attention should be paid to the apron in the direction of water connection of expansion joint during installation.
2. Ensure the safety and hygiene requirements for pipe fittings.
2. 1 exhaust pipe setting
The main function of the vent pipe is to discharge the dirty and harmful gas in the drainage pipeline into the atmosphere, balance the positive and negative pressure in the pipeline and protect the water seal of sanitary ware. Breathing tube can be said to be one of the important accessories to ensure the safety and function of drainage system. In the inspection of drainage system installation, we should attach great importance to the setting of ventilation pipes. In many houses, the drainage pipe extends from the roof as a ventilation pipe, and its diameter should not be less than that of the drainage riser. The height of the breather cap should be 2m higher than the owner's roof. If there are doors and windows around the hole, the breather cap should be 0.6m higher than the hole. Lightning protection measures should be considered for metal snorkel. For individual drainage pipes that can't reach the top, designers should consider the design of convergent snorkel or unventilated riser, and it is strictly forbidden to set suction valves in buildings without reaching the top snorkel.
2.2 trap and floor drain settings
According to the mandatory provisions of Design Code, a trap should be set under the drain of sanitary ware without trap in the structure, and the water seal depth of the trap should be not less than 50 mm In order to "ensure the indoor environment, protect people's physical and mental health and prevent accidents".
Floor drain has the function of removing groundwater. However, the setting of floor drain also involves whether harmful gases can be prevented from entering the room to pollute the indoor environment, so the key concern should be water sealing. Summing up the requirements of the specification, it is best to use a straight-through floor drain and set a trap; Secondly, a deep-water floor drain with a water seal depth of not less than 50mm is adopted. For some places where floor drains are not often used, closed floor drains should be set up.
2.3 Support and hanger settings
There are three situations that should be paid attention to in the setting of supports and hangers. A, outdoor drainage pipe bracket should be made of plastic material, connecting screws with galvanized screws, support firmly; Two, drainage riser through the floor with casing, overhead at the bottom, the bottom of the riser should be set pier or other fixed measures; Thirdly, when the horizontal drainage pipe is long, its fixing measures should be considered. Therefore, in the transfer floor and other types of parts, the bottom of the drainage riser and the corner of the horizontal drainage pipe should be provided with fixed supports and hangers. In addition, if the plastic pipe is equipped with metal supports and hangers, a nonmetallic liner or sleeve should be lined between them.
2.4 setting of firestop ring
The acceptance specification requires that "the exposed drainage plastic pipes in high-rise buildings should be provided with fire rings or fire sleeves according to the design requirements." According to the regulations and instructions in the design code, it should be understood as a drainage plastic pipe with a diameter of110 mm. On both sides of the horizontal pipe passing through the firewall or the wall of the pipeline shaft, a fire ring or a fire sleeve should be set below the floor of the vertical pipe in the pipeline shaft with open layer or interlayer fire blocking. The fireproof sleeve installed on the floor of the riser crossing layer should be not less than 500mm higher than the floor, and the total length installed under the floor should be not less than 500mm, and it should be buried in the floor, which is 2H/3(H is the thickness of the floor); The total length of the horizontal pipe passing through the wall shall not be less than 300mm, and the length of the outer casing on both sides of the firewall and the pipeline well shall not be less than 100mm.
3, ensure the use of functional requirements
3. 1 Installation of pipeline slope and reducing ring
Residential drainage system uses gravity to ensure smooth drainage, so the basic principle to ensure the normal use of drainage pipes is to ensure slope. The slope is too small, the hydraulic condition is poor, and the pipeline is easy to block, which can not meet the use requirements and increases the workload of manual cleaning; The slope is too large, the pipe joint is not tightly inserted, the space occupied is too large, and the pipeline layout is not easy. The pipeline gradient of the horizontal pipe can be properly adjusted by the reducing ring set during reducing, but the setting of the reducing ring should ensure the bottom of the large and small pipes to be flat as far as possible.
3.2 Installation of bottom drainage pipeline
Based on the understanding of the design code, in order to avoid the water seal of the bottom sanitary ware being damaged, according to the requirements of the design code, it is required that the bottom horizontal branch pipe should have a certain distance from the bottom of the riser, increase the diameter of the drainage pipe, or discharge the bottom horizontal drainage pipe to the outside alone.
3.3 Settings of inspection port and cleaning port
The inspection ports on the riser are required to be set outside the lowest floor and the highest floor, and it is best to set one every other floor. If there is a B-bend, an inspection port should be set at its upper part. The horizontal pipe is provided with cleaning ports according to the number of connected sanitary wares. It is advisable to set the ground cleaning mouth flush with the ground. The setting of cleaning port should consider the space of inspection and cleaning operation, and the design standards and acceptance specifications have detailed provisions on this, so they are not repeated here.
The above points are often encountered in the installation of residential drainage system. From the selection of system to the installation of pipe fittings, it may be affected by various factors, so it is impossible to require a unified approach to all details of various types of houses in design and construction. Only in the design and construction stage, in line with the attitude of ensuring the use function and people-oriented, master the basic principles and be familiar with the specifications, strictly control the quality, and finally meet the requirements of the specifications and satisfy the users.