At present, the general non-socket pipe hoop type straight pipe and pipe fittings are divided into two types: A-type flexible interface (flange gland connection) and W-type flexible interface (pipe hoop connection) according to their interface type, referred to as A-type and W-type.
The new flexible interface cast iron drainage pipe adopts high-speed centrifugal casting technology, which has the advantages of dense structure, uniform thickness of pipe wall, smooth inner and outer walls, no trachoma and slag inclusion, high tensile and compressive strength, and the product has the advantages of stable chemical composition, corrosion resistance, fire prevention and non-toxicity, meeting fire safety and environmental protection requirements, no noise, no deformation, and long service life.
A-type pipe: A-type pipe has the advantages of high strength, low noise, good fire performance, long service life, and good flexibility and seismic performance of its connection, but it is found that the installation space required by the socket joint part is large, the pipe body is bulky, and the steel consumption is more, especially in high-rise buildings, which is difficult to be accepted by the construction party.
W-type pipe: In addition to the characteristics of high strength, low noise, good fire performance, long service life, good flexibility and seismic performance of its connection, W-type pipe also has the characteristics of synchronous construction, high utilization rate of pipe, easy pipeline clearance, reduced hydraulic test times, shortened construction period and improved economic benefits. In addition, the bolt of this type of interface is fastened on the outside, and the defect that the flexible interface flange of the socket port is easy to be damaged, and the bolt of the wall foot is difficult to fix, has the advantages of easy operation, so it has strong competitiveness in the selection of building drainage pipes and pipe fittings. In addition, because the length of the straight pipe of the W-type pipe is 3m, the number of intermediate joints is greatly reduced and any length can be cut according to the need, so as to save a lot of pipes, reduce consumption and cost. The W-type non-socket pipe clamp is made of ribbed stainless steel clamp, lined with rubber rings for flexible connection, with high seismic performance and good sealing performance, allowing swing within a certain range and no leakage. Therefore, both at home and abroad, W-tubes have been widely used.
According to the author's experience, in the actual installation project, the above two kinds of pipes are used with better results, which can not only meet the needs of construction quality and use function, but also save materials and reduce costs. Generally, A-type pipes should be used for general drainage horizontal trunk pipes and first-floor outlet pipes, and W-shaped pipes should be used for drainage risers and drainage branch pipes. The advantage of this combination is that due to the good mechanical properties of the flange gland connection, the service life and use function can be guaranteed when the A-type pipe is connected by the flange gland. At the same time, due to its good mechanical strength, it is especially suitable for high-rise drainage and exit horizontal pipes, which can withstand the impact of water from the upper floor. Due to the quick installation and good flexibility of the interface, the W-type pipe should be used as the material for the drainage riser, especially when it is used as the installation and construction of the drainage cross branch pipe in the toilet and bathroom, the good flexibility and tightness of the interface can be used to control the slope of the drainage pipe. At the same time, due to the characteristics of the W-shaped pipe connector, combined with the current situation of the completion and decoration of the residential project (generally the drainage riser of the toilet and bathroom is exposed), when the riser is concealed and decorated, it is convenient for decoration and layout, which can save space and increase the actual use area. In addition, the combination of A-type and W-type pipes, in addition to the above reasons, also because the remaining short material generated in the installation and construction process of A-type pipe can be used as the installation of above-ground drainage cross branch pipe, saving materials and having good economic benefits. Combined with the current use of two kinds of pipes at home and abroad, the author combines his own experience in construction and use, focusing on the installation and construction of W-shaped pipes, and makes a brief introduction.
The connection of the W-shaped pipe is made of stainless steel clamps. Stainless steel clamp parts are composed of rubber sleeves, clamps, perforated rolling shafts and bolts. (See image below).
The interface is sealed with a rubber sleeve, which has a good effect and can withstand vibration from all directions (including strong **), and the outer cover is a stainless steel clamp, which is beautiful and firm and corrosion-resistant. When installing the interface, relax the clamp to the maximum diameter limit, first put the stainless steel jacket into the pipe, and then the two ends of the interface are respectively aligned into the rubber sleeve, and the stainless steel jacket is tightened on the outside of the rubber sleeve to obtain satisfactory results.
The W-tube connection mode determines its characteristics of convenient installation and maintenance, however, due to the connection mode of bolt fastening extruded rubber sealing sleeve, the degree of sealing is mainly dependent on the degree of tightening of the bolt in addition to the relationship with the material itself. According to the author's construction experience, when tightening bolts, it is best to use special tools provided by the manufacturer (there are also on the market at present), so that the fastening effect can be guaranteed and the work efficiency can be improved. In addition, when the drainage pipe is blocked, it is easy to remove the clamp piece, which is an advantage that traditional other pipes do not have.
In order to ensure the quality of construction and the use of functions, and to prevent the occurrence of phenomena such as running, rising, dripping, and leaking, in the actual project, in addition to the conventional water through ball test, the author also adopts the method of combining the full water test and tapping to listen to the sound. Carry out a full water test spot check on the materials entering each time, and only after all are qualified can they enter the site, when using them, tap the material, if the sound is light and brittle, it is qualified, once there is a buzzing sound, it means that there is a rupture. Secondly, after the construction of the pipeline is completed every day, the nozzle is temporarily blocked to prevent debris from falling into the pipeline and clogging it. After the installation of each toilet and bath, the drainage branch pipe is fully tested to check whether the interface is leaking, and the problem is dealt with in time.
Due to the characteristics of the new flexible interface cast iron drainage pipe, it is widely used in domestic high-rise buildings, and can replace related imported products, and meets the requirements of the Ministry of Construction's document selection. It can be said that it has all the advantages of the old-fashioned socket cast iron drainage pipe and plastic drainage pipe, the selection of this kind of pipe, not only saves investment, but also solves the defects of the previous drainage pipe, has the characteristics of high strength, corrosion resistance, low noise, seismic and fire resistance, and meets the requirements of the use function to a greater extent, maximizes the layout of the indoor space, and receives good social and economic benefits.
In short, the application of the new flexible interface cast iron drainage pipe in the building drainage system is in the initial stage, and there are many problems that need to be further clarified and verified.