According to different needs, polyethylene pipe system can be applied to a variety of connection methods (but it should be noted that not all the connection methods suitable for other pipe systems are suitable for the application of polyethylene pipe system), and the main ones are as follows:
Polyethylene pressure pipe (for water supply, gas, industrial infusion) : hot melt connection, electric melt connection, mechanical connection (including mechanical compression connection, flange connection and connection with prefabricated steel-plastic transition pipe).
I. connection of polyethylene pressure pipe
1 hot melt connection
The hot melt connection of polyethylene pipeline system includes hot melt butt joint (including saddle type connection) and hot melt socket connection.Hot melt socket connection is suitable for pipe fittings with small diameter (generally less than DN63 mm in diameter), because the pipe wall of pipe fittings with small diameter is thinner and the section is smaller, it is not easy to ensure the quality by butt joint.Hot melt butt joint is suitable for pipe fittings with large diameter, less material than socket joint, easy to manufacture, and because the oxidation surface layer is cut off before welding, welding pressure can be controlled, the quality is easy to ensure.Look from development trend, use hot melt butt joint is mainstream.
It has had been proved that the pipe fittings made of company's grades of polyethylene pipe materials (conforming to the standard and with little difference in melt flow rate MFR) can be connected by hotMelt. But because the domestic production of polyethylene pipe fittings, 2 in the material is not fully in line with the standard pipe materials,So in the need of the company brands and batch of polyethylene pipe fittings of hot - melt connection, it is it to pass the test and testing.
The process and equipment (tools) for hot-melt connection of polyethylene piping system are relatively simple.In recent years, many problems occurred in connection of polyethylene pipeline engineering.The difficulty is that it is difficult to detect the quality of hot-melt connection on site (under the condition of not breaking the connection).Foreign countries are exploring the quality of hot melt connection using ultrasonic testing, but the field has not been widely used, currently the general field or rely on 'visual testing'.The guarantee of the quality stability of hot melt connection mainly depends on strictly observing the specified operating procedures (especially to strictly control the temperature, pressure and time three parameters).It is suggested that the polyethylene pipe fitting manufacturers should work out detailed operation rules for the pipe fittings of their own enterprises by means of tests and tests (combined with the characteristics of the hot-melt connection equipment adopted) in accordance with relevant specifications (provisions on the principle of comparison).And through training and consultation to help builders master the operating procedures.Most of the major companies producing polyethylene pipe systems in the world have these operating procedures to guide hot-melt connections.A practical approach to quality control is described in the PPI manual: perform an experimental hot-melt connector on site each day and perform a 'tape bending test' (destructive testing of equipment is not required) to determine whether the process and equipment need to be adjusted.
2 electric fusion connection
The electric fusion connection includes the electric fusion socket connection and the electric fusion saddle connection.
The prominent advantages of electric fusion connection are reliable quality (reduce human factors) and high construction efficiency.Due to the high technical requirements and high cost, the electric melting pipe fittings were mainly used in the gas pipeline system with small diameter in the early stage.In recent years, with the development of technology, the application of electric fusion connection is more and more extensive.It is not only applied to water supply pipe system, drainage pipe system, but also started to be applied to larger diameter (but the main market of electric melting pipe fittings is in the range of dn20-250mm).
From the technical line there are two categories: one is the first electric wire wrapped in the mold on the metal mandrel or wrapped in the prefabricated polyethylene thin sleeve, into the injection mold injection into the embedded electric wire melting pipe.Among them, there are different designs (each has advantages and disadvantages) such as electric hot wire semi-embedding (metal wire is semi-exposed), full embedding (metal wire is not exposed), electric hot wire pre-coating polyethylene layer (metal wire is not exposed);The degree of automation of all or part of all or part of manual operation with a manipulator.The other is the use of injection plastic polyethylene pipe and then mechanical processing wiring process.
Cangzhou Steel Pipe Group (CSPG) Co., Ltd. is a large-sized, key metallurgic enterprise of Hebei Province in North China, whose history dates back to 1994. CSPG currently em/paces six member companies with products varying from SSAW, LSAW, ERW, seamless steel pipes to 3PE pipes, galvanized pipes, casing pipes, etc. A Joint-stock corporation, CSPG occupies an area of 600,000 square meters with a total asset of $530 million.
Specialized in the production of straight welded pipe spiral pipe galvanized pipe 3PE/3PP/FBE/TPEP internal and external epoxy powder internal and external epoxy resin cement mortar two cloth three oil buried pipeline IPN8710 non-toxic drinking water internal and external plastic coated lining plastic and other anti-corrosion pipe fittings for oil and gas pipeline water conservancy projects
Executive standard :DIN30670 DIN30678 CSA Z245 AFNOR nf49-710/711 NACE rp0394/0490 AWWAC 210/C213GB/T9711 API 5L ISO 3183Material: Q235B/Q355BGR A GR B x42-x80 l245-l555
Business scope: 21.3mm-3620mmLSAW submerged arc welded pipe 325-2020mmERW straight welded pipe 6mm-711mmSMLS seamless tube 10-1120mmSSAW spiral steel tube 219-3620mmDemand for quality suppliers and partners