PVC pipe construction technology and maintenance
PVC is the main component of PVC, in addition to other ingredients to enhance its heat resistance, toughness, ductility and so on. The top layer of this surface film is a lacquer, with the main component in the center being PVC and the bottom layer being a back-coated adhesive. It is a favorite, popular and widely used synthetic material in today's world. Its global usage ranks second among all composites.
The essence of PVC is a vacuum plastic film, used in the surface of various types of panel packaging, it is also known as the decorative film, with plastic film, used in building materials, packaging, medicine and many other industries. Building materials industry accounted for the largest share of 60%, followed by the packaging industry, there are a number of other small-scale application of the industry.
First, PVC pipe construction technology
1, the pipe processing: the amount of pipe to take the length of the decision, available manual hacksaw saw or circular saw, sawing sawing. Both ends of the incision should be kept flat, with the butterfly to remove burrs and chamfer, chamfer should not be too large.
2, the pipe fittings of the bond: Before the test must be assembled, cleaning the pipe end of the outer tube about 50mm length and the inner wall of the tube bearing, and then coated with acetone cotton yarn scrub, and then the two bonding surface Brush with a layer of adhesive evenly coated, shall not leak coated. Complete coating is rotated to the desired combination of angles, the pipe into the pipe fitting bearing port, with a mallet percussion, so that all the pipe into the socket, in two minutes can not be opened or switch direction, and promptly wipe out the joints extrusion Viscose to keep the pipe clean.
A riser installed a telescopic section of each layer to compensate for the thermal expansion and contraction of the reverse flow tube.
b. Three-way installation should pay attention to the direction along the water, easy to install when the natural formation of horizontal pipe slope
c. stand pipe height of 3m each person, consider the installation of a hoop. Horizontal pipe is installed every time a 0.6m elevator.
d. Horizontal pipe, drain straight line distance greater than the provisions of Table 4, should be set to check the mouth or cleaning port.
Second, PVC pipe
production line equipment features
1, Raw material mixing: adding PVC stabilizer, plasticizer, antioxidant and other auxiliary materials into the high-speed mixer according to the proportion and technology. The materials and mechanical self-friction make the material temperature rise to the set process temperature, The mixer reduces the material to 40-50 degrees so it can be added to the hopper of the extruder.
2, Extruder part: The machine is equipped with quantitative feeding device, so that the amount of extrusion and feeding amount to match, to ensure stable extrusion products. Due to the characteristics of the tapered screw, feeding section has a larger diameter, the heat transfer area of the material and the shear rate is relatively large, is conducive to material plasticization, measuring section of the screw diameter is small, reducing the heat transfer area and the melt The shear rate, the melt can be extruded at lower temperatures. When the screw is rotated in the barrel, the PVC mixture is plasticized and then pushed to the nose, thereby achieving compaction, melting and kneading homogenization; and achieving the purpose of exhausting and dehydrating. Feeding device and screw drive using frequency control, speed synchronization can be achieved
3, the extrusion die part: After compaction, melting, mixing homogenized PVC, the follow-up material is pushed to the die by the screw, extrusion die is the pipe forming the Guan Jian parts.
4, vacuum stereotypes for the pipe stereotypes, cooling, vacuum stereotypes on the tank equipped with stereotypes and cooling for the vacuum system and water circulation system, stainless steel tank, circulating water spray cooling, vacuum stereotypes on the front and rear mounted on the water tank and mobile devices, Height adjustment manual device.
5, Traction machine for continuous, automatic cooling of the pipe has been hardened from the machine at the lead, frequency control.
6, Cutting machine: It is controlled by the length of the travel switch according to the required length, automatic cutting, and delay the shelf, the implementation of 流水生产, cutting machine to set the switch signal for instructions, to complete the cutting process, cutting and pipe operation Maintain synchronization, the cutting process is completed by the electric and pneumatic drive, the cutting machine is equipped with a vacuum device, the cutting debris generated by timely sucked and recovered.
7, flip rack flip action by pneumatic cylinder control to achieve, flip rack with a limit device, when the cutting saw cut pipe, the pipe continues to transport, after the delay, the cylinder into work to achieve the flip action , To discharge the purpose. Discharge after a few seconds delay automatically reset, waiting for the next cycle.
Third, PVC pipe construction and maintenance
PVC pipe connections are the main sealing ring, bonding and flange connection 3 kinds. Pipe diameter greater than or equal to 100 mm pipe commonly used apron interface; pipe diameter less than 100 mm generally use adhesive joints, and some live joints. Pipelines in the sewer or other pipelines, the general use of metal pipe, then the plastic pipe and metal pipe flange connection. Valve before and after the connection with the pipeline are also used flange connection.
1, when the small-diameter pipe using solvent bonding, the socket should be rounded down to form the bevel, and to ensure that the fracture is formed and vertical axis, so as to be firmly bonded, to avoid water leakage.
2, the general diameter greater than or equal to 100 mm PVC pipe are used apron interface. Personnel must be arranged before the installation of chamfering pipe socket parts, but also check the rubber ring quality is qualified. Installation must be sockets, rubber ring and other clean.
3, the traditional pipeline installation trench dredging only required to pipe into the trench and can be sealed, without loosening the original soil, you can not compress the ram.
4, the general PVC pipe branch can be used to open three-way or vertical stop plug split. In the construction of a saddle-shaped parts can be added a couple of three-way, and with the U-shaped bolt tight, so that thickened the pipe wall, and then drill directly in the open teeth, and then threaded plastic parts out. Tests show that with this method after construction pressure test acceptance can meet the requirements of the specification. In addition, the water flow generated in the pipe thrust position, such as elbows, tees and pipe end seal plate and other parts should be set to push the pier to withstand the thrust of water flow.