How welded wire skeleton plastic polyethylene composite pipe?
A. welding process three factors: voltage, current and time are the parameters to set welding, welding parameters are important factors to ensure the quality of electrofusion welding. From the point of view of welding, setting the correct welding parameters essentially provides the welding area with the right amount of heat (electric energy is converted into heat energy). B. parameter correction: welding parameters may change from time to time (season), because (different regions), due to environmental changes and meteorological conditions in different geological conditions to make the appropriate adjustments to the strict discipline: on-site welding welding process parameters is confirmed, not allowed to change, must strictly abide by. C. pipes and fittings pipe inspection: focus on examination of the pipe surface have deep scratches, pipe inside and outside surface are unrecoverable protrusions or pits, pipe port sealing ring if there is a crack or fall off; to focus on examination of pipe thermal resistance wire is energized, whether there is a deep scratch damage to hot wire etc.. D. fixed length Piping: according to the needs of the site, the pipe needed in the process of pipe connection can not be entirely the whole pipe, so it is necessary to cut the fixed length pipe on the spot. The electric cutting saw is generally used in the field, because it is limited by the operating space at the bottom of the ditch,
Steel skeleton plastic composite pipe laying and steel pipe, and pipe connection generally adopts electric melting connection and sleeve flange connection in two ways, and the connection between the pipe between the welding connection, pipes and pipe fittings fused the control points of construction. The important temperature parameters of polyethylene thermoplastic are glass temperature, viscous flow temperature, crystal melting temperature and pyrolysis temperature. When the plastic is above the viscous flow temperature or the crystal melting temperature, the plastic is melted into a viscous fluid by the solid state, and the welding is carried out in this temperature range. Hot melt welding principle established in semi crystalline thermoplastic polyethylene (HDPE crystallization degree is 85% ~ 95%) melting properties, melting process of polyethylene is basic ground connection interface by heating to melt state, contact theory according to the viscosity, by controlling the temperature and time are connected into a bond in under the action of pressure, the fusion zone can reach the same intensity of pipe.
Steel skeleton plastic composite pipe construction process is as follows: trench excavation, pipe length, pipe, hot-melt sleeve and pipe end grinding, the fixed, welding, cooling, fixture, pipeline pressure test, demolition of trench backfill.
