Strengthen anticorrosion polyethylene steel-plastic crossover sub and processing technology
Technical field
The present invention relates to a kind of pipeline connection fittings, relate in particular to a kind of pipeline connection fittings that are used for FLUID TRANSPORTATION such as combustion gas, liquid, be mainly used in the jointing and the processing technology of polyethylene (PE) plastic pipe and metallic conduit.
Background technique
In fluid-transporting tubing fields such as combustion gas, pipeline commonly used is generally the plastic pipe of metallic conduits such as steel pipe and polyethylene (PE), and wherein metallic conduit is generally used for the Intermediate High Pressure fluid delivery system, and it is main that plastic pipe then generally is used for low pressure; In addition, for the sake of security, national correlation engineering regulation and stipulation, plastic pipe do not allow directly to get into end-user indoor of pipeline.Therefore at high pressure pipe line to the low pressure pipeline transition, and plastic pipe needs to adopt polyethylene (PE) steel mould crossover sub when the garden pipe is registered one's residence usually.The antiseptic property of polyethylene (PE) pipeline is very outstanding; Its design service life was 50 years; And supporting with it steel is moulded the steel pipe end of crossover sub because what adopt is steel material, and the antiseptic property of itself does not catch up with the requirement of polyethylene (PE) pipe far away, adds that steel moulds the crossover sub majority and be embedded in moist underground; Or be exposed in the air, therefore require very high to its corrosion-resistant.
Common steel is moulded conversion mostly just at anti-corrosion materials such as external spray one deck nylon of steel pipe end or epoxy resin; In accumulating, installation, and in the later stage using process, factor such as collided with easily; The problem that anticorrosive coat comes off occurs, antiseptic effect and working life are all undesirable.And also strengthen anti-corrosion measure on the engineering at present in other multilayers that adopt; Often have also that complex procedures, construction requirement are high, anti-corrosion material can't be simultaneously and defective such as reliable bonding simultaneously between steel pipe and polyethylene (PE) pipe; There are various problems, are being difficult to reach perfect unification aspect antiseptic effect and the Economy.
Summary of the invention
Main purpose of the present invention is that to solve existing in prior technology not enough, thus through mould, the selection of perfect design of Sealing Structure and compatible anti-corrosion material between the steel, reach the polyethylene steel-plastic crossover sub of perfect antiseptic effect.
For cooperating above-mentioned purpose; The complete anticorrosion polyethylene steel-plastic crossover sub of the reinforcement processing technology of one cover that the present invention has studied success; Guarantee polyethylene (PE) no matter steel is moulded the crossover sub direct-burried underground; Still be exposed in the air, all can perfectly realize and polyethylene (PE) the pipeline purpose in identical working life.
Above-mentioned technical problem of the present invention mainly is able to solve through following technical proposals:
The anticorrosion polyethylene steel-plastic crossover sub of a kind of reinforcement,
Have polyvinyl plastics pipe fitting and metal pipe element, said polyvinyl plastics pipe fitting and the socket of metal pipe element part is characterized in that: said polyvinyl plastics pipe fitting is socketed in the metal pipe element outside; The metal pipe element outside of said polyvinyl plastics pipe fitting and metal pipe element socket place is processed with 5-8 road back-off structure, and both sides are processed with 2 to 3 circle seal ring circular grooves, in the said circular groove O-ring seals are installed; There is the wedge metal sleeve polyvinyl plastics pipe fitting outside of said polyvinyl plastics pipe fitting and metal pipe element socket place; Metal pipe element outside after connection coats DH solventless epoxy coating layer, is coated with the PUR winding layer in said epoxy paint layer, wedge metal sleeve and part polyethylene plastic tube outside, is coated with the PEX thermal contraction casing tube in said PUR winding layer outside; Form interference fit between said metal pipe element and polyvinyl plastics pipe fitting and wedge metal sleeve and the polyvinyl plastics pipe fitting; The tapering of said wedge metal sleeve is 2 ± 0.2 °.
A kind of processing technology of strengthening anticorrosion polyethylene steel-plastic crossover sub,
It is that the polyvinyl plastics pipe fitting partly is socketed in the metal pipe element outside that the anticorrosion steel of said reinforcement is moulded crossover sub; There are 5-8 road back-off structure and 2 to 3 circle seal ring circular grooves in the metal pipe element outside of socket place; There is the wedge metal sleeve plastic pipe outside of socket place, and the three forms interference fit;
1), selects materials
According to product specification, select the seamless steel pipe that is used for processing metal pipe fitting and wedge metal sleeve for use;
Adopt special use to add thick polyethylene (PE) injection moulding accessory, the corner of said injection moulding accessory is through chamfered; Said adding thickness is the 1.2-1.4 of conventional design thickness;
2), gold machining:
The outside of metal pipe element is processed with 5-8 road back-off structure and 2 to 3 and encloses the circular groove that is used to install O-ring seals; Said back-off structure and circular groove are positioned at the position of polyvinyl plastics pipe fitting and metal pipe element socket place; Said circular groove is positioned at both sides or the both sides and the neutral position of socket place;
The wedge metal sleeve adopts high-precision lathe in machining, the internal diameter size tolerance is controlled at ± 0.03mm in;
3), plastic pipe is accurately processed:
Plastic pipe by operation card requirement injection moulding blank after, need to place more than 1 month, inner to eliminate pipe fitting because the internal stress that production process produces;
Accurately before the processing, earlier the moulding blank is moved in 20 ℃ of isoperibols through the status adjustment more than 24 hours;
Adopt the high precision numerical control lathe pair accurately to process with metal pipe element and the supporting inner and outer surface of wedge metal sleeve, the precision of interior external diameter is controlled at ± 0.06mm in;
4), assembling:
Put seam ring and O-ring seals in the metal pipe element outside;
The polyvinyl plastics pipe fitting is placed in metal pipe element outside, till seam ring place, make metal pipe element and the polythene material that cooperates with it between form tight interference fit; Both reach the effect that connects two kinds of materials, born the part seal action simultaneously.
Highi degree of accuracy wedge metal sleeve is placed in vinyl tube spare outside, till seam ring place, the polyvinyl plastics pipe fitting is inwardly pushed, both form reliable connection;
5), metal pipe element, wedge metal sleeve and the clad processing of polyvinyl plastics pipe fitting outside:
The metal pipe element skin sprays one deck DH solventless epoxy coating in advance, and this coating is two components, is applied after stirring in proportion by A, B component, has characteristics dried soon, thick film;
The DH solventless epoxy coating carries out evenly polishing fully to the epoxy coating surface on the self-control polisher that adopts lathe to reequip after drying, make the coating layer surface more coarse, significantly improves the Adhesion force with other anti-corrosion materials;
The metal pipe element that scribbles the DH solventless epoxy coating is carried out 190 ℃-210 ℃ high temperature preheating, fully eliminate the moisture of epoxy paint layer;
To DH solventless epoxy coating layer through abundant heat drying and metal pipe element behind high temperature preheating; Adopt wide about 50mm; The low molecular weight polyethylene Hot melt adhesive tape of thick 0.5-1mm; Spiral amount of lap according to 50% is twined covering, and coverage rate relates to the part of metal pipe element, wedge metal sleeve and polyethylene pipe end;
According to the total length suit PEX thermal contraction casing tube of product, said thermal contraction casing tube covers all Hot melt adhesive tape winding zone;
Adopt special-purpose flame gun, between FT was controlled 300-500 ℃, opsition dependent carried out heat treated to thermal contraction casing tube successively; Coking needs to adopt the short period for fear of PEX heat-shrinkable T bush outer surface Yin Wendu is too high, comes the mode of the moving heating of flyback repeatedly, and the local time that stops heating continuously should not surpass 3s, and entire product is controlled in the 15min overall heating time approximately.Fully the thermal contraction casing tube after the heating can fully bounce back; Closely hold outside tightly at PUR; And further melt inner polyethylene (PE) Hot melt adhesive tape through the heat that thermal contraction casing tube passes over; Make the Hot melt adhesive tape upper and lower surface of fusion mould crossover sub steel pipe end with thermal contraction casing tube and steel respectively and polyethylene (PE) pipe end is bonding, thereby be welded together;
Each layer anticorrosive coat is through the flame gun heating; After tentatively merging between each layer; Adopt the principle of electromagnetic induction heating again, steel pipe is carried out double heating handle, set technology according to the Different products specification; The heating and temperature control of electromagnetism heating collar is at 160 ± 10 ℃, and be controlled in the 5min whole heating time; Because electromagnetic induction heating is only effective to metal; Therefore; The heating heat of this moment is by the outwards evenly diffusion of the steel pipe of inside, just can form perfect complementary effect with flame gun external heat before, and heat transmits from outside to inside with diffusion from inside to outside and combines; Make the hot melt more even distribution of each interlayer, bonding more reliable between each layer anticorrosive coat.
Beneficial effect of the present invention is: through mould, perfect design of Sealing Structure between the steel; The selection of compatible anti-corrosion material and unique treatment process; No matter thereby guarantee that the present invention's direct-burried is underground; Still be exposed in the air antiseptic effect excellent more, the perfect realization and polyethylene (PE) pipeline identical working life far beyond other like products.
Description of drawings
Accompanying drawing 1 is a kind of structural representation of the present invention.
Description of reference numerals: 1, polyvinyl plastics pipe fitting, 2, the wedge metal sleeve, 3, metal pipe element, 4, back-off structure, 5, the seal ring circular groove, 6, the O RunddichtringO, 7, DH solventless epoxy coating layer, 8, the PUR winding layer, 9, the PEX thermal contraction casing tube.
Embodiment
Pass through embodiment below, and combine accompanying drawing, do further bright specifically technological scheme of the present invention.
Embodiment 1:
Polyethylene steel-plastic crossover sub as shown in Figure 1 has polyvinyl plastics pipe fitting 1 and metal pipe element 3, said polyvinyl plastics pipe fitting and the socket of metal pipe element part, and said polyvinyl plastics pipe fitting is socketed in the metal pipe element outside; The metal pipe element outside of said polyvinyl plastics pipe fitting and metal pipe element socket place is processed with 6 road back-off structure 4, and both sides are processed with 2 circle seal ring circular grooves 5, and O-ring seals 6 is installed in the said circular groove; There is wedge metal sleeve 2 the polyvinyl plastics pipe fitting outside of said polyvinyl plastics pipe fitting 1 and metal pipe element 3 socket places; Metal pipe element outside after connection coats DH solventless epoxy coating layer 7; Be coated with PUR winding layer 8 in said epoxy paint layer, wedge metal sleeve and part polyethylene plastic tube outside, be coated with PEX thermal contraction casing tube 9 in said PUR winding layer outside; Form interference fit between said metal pipe element and polyvinyl plastics pipe fitting and wedge metal sleeve and the polyvinyl plastics pipe fitting; The tapering of said wedge metal sleeve is 2 ± 0.2 °.
Processing technology:
1), selects materials
According to product specification, select the seamless steel pipe that is used for processing metal pipe fitting and wedge metal sleeve for use;
Adopt special use to add thick polyethylene (PE) injection moulding accessory, the corner of said injection moulding accessory is through chamfered; Said adding thickness is 1.2 of conventional design thickness;
2), gold machining:
The outside of metal pipe element is processed with 6 road back-off structure and 2 and encloses the circular groove that is used to install O-ring seals; Said back-off structure and circular groove are positioned at the position of polyvinyl plastics pipe fitting and metal pipe element socket place; Said circular groove is positioned at both sides or the both sides and the neutral position of socket place;
The wedge metal sleeve adopts high-precision lathe in machining, the internal diameter size tolerance is controlled at ± 0.03mm in;
3), plastic pipe is accurately processed:
Plastic pipe by operation card requirement injection moulding blank after, need to place more than 1 month, inner to eliminate pipe fitting because the internal stress that production process produces;
Accurately before the processing, earlier the moulding blank is moved in 20 ℃ of isoperibols through 24 hours status adjustment;
Adopt the high precision numerical control lathe pair accurately to process with metal pipe element and the supporting inner and outer surface of wedge metal sleeve, the precision of interior external diameter is controlled at ± 0.06mm in;
4), assembling
Put seam ring and O-ring seals in the metal pipe element outside;
The polyvinyl plastics pipe fitting is placed in metal pipe element outside, till seam ring place, make metal pipe element and the polythene material that cooperates with it between form tight interference fit; Both reach the effect that connects two kinds of materials, born the part seal action simultaneously.
Highi degree of accuracy wedge metal sleeve is placed in vinyl tube spare outside, till seam ring place, the polyvinyl plastics pipe fitting is inwardly pushed, both form reliable connection;
5), metal pipe element, wedge metal sleeve and the clad processing of polyvinyl plastics pipe fitting outside
The metal pipe element skin sprays one deck DH solventless epoxy coating in advance, and this coating is two components, applies after being stirred in the ratio of 1:1 by A, B component, have do soon, the characteristics of thick film;
The DH solventless epoxy coating carries out evenly polishing fully to the epoxy coating surface on the self-control polisher that adopts the lathe repacking after drying, make the coating layer surface more coarse, significantly improves the Adhesion force with other anti-corrosion materials;
The metal pipe element that scribbles the DH solventless epoxy coating is carried out 200 ℃ high temperature preheating, fully eliminate the moisture of epoxy paint layer;
To DH solventless epoxy coating layer through abundant heat drying and metal pipe element behind high temperature preheating; Adopt wide 50mm; The low molecular weight polyethylene Hot melt adhesive tape of thick 0.5mm; Spiral amount of lap according to 50% is twined covering, and coverage rate relates to the part of metal pipe element, wedge metal sleeve and polyethylene pipe end;
According to the total length suit PEX thermal contraction casing tube of product, said thermal contraction casing tube covers all Hot melt adhesive tape winding zone.
Adopt special-purpose flame gun; Between 400 ℃ of the flame gun FT controls, opsition dependent carries out heat treated to thermal contraction casing tube successively, adopts the short period; Come the mode of the moving heating of flyback repeatedly; The local time that stops heating continuously should not surpass 3s, and entire product is controlled in the 15min overall heating time approximately, and fully the thermal contraction casing tube after the heating can fully bounce back; Closely hold outside tightly at PUR; And further melt inner polyethylene (PE) Hot melt adhesive tape through the heat that thermal contraction casing tube passes over, make the Hot melt adhesive tape upper and lower surface of fusion mould crossover sub steel pipe end with thermal contraction casing tube and steel respectively and polyethylene (PE) pipe end bonding, thereby be welded together.
Adopt the principle of electromagnetic induction heating again, steel pipe is carried out double heating handle, the heating and temperature control of electromagnetism heating collar is at 160 ± 10 ℃, and be controlled in the 5min whole heating time.Because electromagnetic induction heating is only effective to metal; Therefore; The heating heat of this moment is by the outwards evenly diffusion of the steel pipe of inside, just can form perfect complementary effect with flame gun external heat before, and heat transmits from outside to inside with diffusion from inside to outside and combines; Make the hot melt more even distribution of each interlayer, bonding more reliable between each layer anticorrosive coat.
Above-mentioned processing, polyvinyl plastics pipe fitting 1 closely connect after pushing through wedge metal sleeve pipe 2 with metal pipe element 3, form a sealed whole, mainly bear the function of overall product pressure-bearing.
2 pairs of polyvinyl plastics pipe fittings of wedge metal sleeve 1 form extruding closely, guarantee that polyvinyl plastics pipe fitting and metal pipe element form reliable and firm being connected.
Back-off structure 4 forms interference fit with the internal surface of the polyvinyl plastics pipe fitting 1 of the deformation that is squeezed, and reaches the effect that connects and seal.
O RunddichtringO 6 receives both compressional deformations between polyvinyl plastics pipe fitting and metal pipe element, play reliable seal action, thereby stops the generation of escape of liquid problem.
DH solventless epoxy coating layer 7 is coated in treated metal pipe element 3 outer surfaces uniformly through the mode of spraying, plays last one corrosion-resistant effect.
Low molecular weight polyethylene (PE) PUR winding layer 8 uniform winding are in the outside of DH solventless epoxy coating layer 7, wedge metal sleeve pipe 2 and polyvinyl plastics pipe fitting, and promptly play and strengthen the corrosion-resistant effect, but different anticorrosive coats of secure bond again.
PEX thermal contraction casing tube 9 is sleeved on the outside that has covered low molecular weight polyethylene (PE) PUR winding layer 8, and through the special process operation, tightens in PUR winding layer 8 outsides, plays first road, also is most important one antisepsis.
In use, the left end and the polyethylene pipe of polyvinyl plastics pipe fitting 1 are connected to the plastic pipe end through modes such as hot melts, and an end of metal pipe element 3 can be connected with the mode of metallic conduit through screw thread or welding.
Embodiment 2:
Adopt special use to add thick polyethylene (PE) injection moulding accessory, said adding thickness is 1.4 of conventional design thickness;
The outside of metal pipe element is processed with 8 road back-off structure and 3 and encloses the circular groove that is used to install O-ring seals.
Adopt wide 50mm, the low molecular weight polyethylene Hot melt adhesive tape of thick 1.0mm twines covering according to 50% spiral amount of lap.
All the other are with embodiment 1.
In sum, the present invention adopts two pass O type circle sealing configuration, between plastic and metalwork, forms mechanical connection through the wedge metal sleeve; Reach reliable sealing effect; Adopt three layers of compatible anti-corrosion material simultaneously, and adopt particular processing technology, thereby reach perfect antiseptic effect.