Stainless steel pipe with thin-walled composite inner wall of carbon steel pipe, lined with stainless steel composite pipe is a bimetal composite pipeline, mainly composed of carbon steel pipes as the base pipe, and the stainless steel liner pipe is combined with the base pipe through composite processes such as shrinkage, cold expansion, explosion or brazing.
This kind of pipe is composited with thin-walled stainless steel pipes on the inner wall of the steel pipe, which greatly improves the corrosion resistance of the steel pipes, while retaining the mechanical strength and good sealing of the steel pipes..
- Advantages
1. No staining, no nodules, corrosion resistance
Composite in steel pipe Thin-walled stainless steel pipe, because stainless steel contains18%-20% chromium, an extremely thin chromium oxide film is formed during use. This film prevents metal from continuing to oxidize, so stainless steel has strong corrosion resistance. It can not only withstand the corrosion of water and air, but also withstand the corrosion of weak acids and weak alkalis. The corrosion resistance and density of stainless steel are stronger than the galvanized layer of galvanized steel pipes. so,Lined stainless steel composite steel pipe During use, there is no need to worry about scaling or noduling caused by rust on the inner wall, which will cause the inner hole to shrink.
The corrosion resistance of stainless steel is much higher than that of carbon steel, and is lined with stainless steel pipes, which can be used to transport acidic or alkaline chemical fluids.
2. High strength, pressure resistance, stretch resistance
Lined stainless steel composite steel pipe The outer steel pipe in the middle is made of welded steel pipe, seamless steel pipe, and spiral seam welded pipe. The tensile strength of welded steel pipes or seamless steel pipes is greater than that of335MPa, elongation is greater than 15%, and the elongation of the steel pipe inline stainless steel composite steel pipe reaches more than 25%. The steel pipes have undergone water pressure tests of more than 3.0MPa and pass the standard specified Bending test,flattening test,Fracture toughness test, metallographic inspection, tensile test and higher strength pressure test. After the composite stainless steel pipes in the outer steel pipes increase the total wall thickness and strength, it can not only be used for civil water and gas transmission, but also for industrial fluids. When welded steel pipes are used in outer steel pipes, the strength reliability of composite steel pipes is improved because the welds of outer steel pipes and stainless steel pipes are not in the same position.
3. Can be soldered
Welding can be used. Before welding, mechanical methods and organic solvents should be used to remove at least each side of the weld surface and the welding bevel.Oil stains, rust, metal chips, oxide films and other dirt within 20mm. Welding equipment should meet the welding process requirements and comply with the relevant equipment standards. In the welding procedure, first weld the composite material (stainless steel pipe), then the transition layer, and finally the substrate (carbon steel pipe).
The surface of the composite weld should be kept as smooth and smooth as possible from the composite surface. When welding the transition layer, the amount of melting of the base metal should be minimized as much as possible while ensuring good fusion, that is, the melting and ratio should be reduced. Clean after welding, and carefully clean the welding slag, welding tumor splashes and other dirt on the surface of the weldment after welding. Welds should be partially trimmed if necessary. After cleaning after welding, welder marks should be stamped on obvious parts near the substrate weld for future inspection.
4. Can be connected to flange,CanThreaded connection
Lined stainless steel composite steel pipe The joint seal is a double-layer seal, the outer layer is a pipe thread seal, and the inner layer is a special structure silicone rubber seal ring seal, ensuring the reliability of the piping system seal. Can also be coated on the outside of the shoulder-type forged cast fittingsHA alloy coating has corrosion resistance performance that reaches the corrosion resistance of stainless steel.
5. YesTrench connection
Because of the large diameter of the pipe fittings of DN125-DN600, it is difficult to process threads and tighten threads, so the pipe fittings of DN125-DN600 should use grooved pipe joints and plastic lining blue. Trench pipe joints are carried out on the outer surface and end surfacesElectrostatic plastic sprayingTreatment, can also be plated outside the ductile iron grooved pipe jointHA alloy coating, the corrosion resistance level of the coating reaches the corrosion resistance level of stainless steel. Silicone rubber or food grade inside the connectorNitrile rubberThe sealing ring, fluid flows in the pipe and will not come into contact with the outer steel pipe.
exist Lined stainless steel composite steel pipe The outer surface of the end of the end is extruded out of the groove, and the two end sides of the grooved pipe joint are pressed into the groove. The grooved pipe joint consists of two flap grooved pipe joints, and the grooved pipe joints are connected by bolts and nuts. When the bolt and nut are tightened, the two grooved pipe joints are tightly clamped together to tighten the silicone rubber sealing ring in the grooved pipe joint. The silicone rubber sealing ring tightly hugs the ends of the two-section pipes together, and the fluid flows in the tube and the sealing ring, ensuring the sealing of the fluid flow.
In order to solve the corrosion problem of the end face of the pipe, an anti-corrosion sleeve is designed. The outer surface of the anti-corrosion sleeve and the inner surface of the inner surface of the stainless steel composite steel pipe lined is formed, so that the anti-corrosion sleeve on the end face of the stainless steel composite steel pipe lined is closely attached to the end face of the pipe lined with the stainless steel composite steel pipe. Sealant is applied between the anti-corrosion sleeve on the end face and the end face and the inner surface of the steel pipe. The sealant is a two-component. When used, the two components are mixed together to immediately generate a great adhesion force. The end-face anti-corrosion sleeve and sealant well solve the corrosion protection problem of the end-face of the pipe when using grooved connections.
6. Resistant to high temperatures, can transport hot water, boiling water, steam, low temperatures, good brittleness, small expansion coefficient
The thermal expansion and contraction of plastics exceeds that of steel10 times, and the extension capacity of plastic when it shrinks when it is cold, it is much lower than that of steel. Therefore, when the water in the pipe is frozen and expanded in cold seasons, the plastic pipe cannot shrink and recover after it is frozen and expands, and it expands multiple times, causing the plastic to expand beyond its limit and breaks brittle.Welded steel pipes Ensure elongation exceeds 15%,Stainless steel pipe The elongation ensures that it exceeds 25%, an outer steel pipe that can elongate and expand, and a stainless steel pipe with better elongation is lining to avoid brittle breakage when the water in the pipe is frozen and expands.
7. Good hygiene performance and can transport clean water
Since stainless steel pipes are not corroded by fluid during use, the stainless steel pipe body has no impurities entering the fluid, and the stainless steel composite steel pipe is lined with Stainless steel threaded pipe fittings,Stainless steel flange, stainless steel welded pipe fittings, the fluid does not come into contact with the outer steel pipe, and the fluid only comes into contact with the stainless steel, so the inner lined stainless steel composite steel pipe can replace pure stainless steel pipes to transport drinking water.
8. Low price
Steel pipes are covered with Thin-walled stainless steel pipe This reduces manufacturing costs and ensures thickness to ensure strength, so that the cost of installing inner lined stainless steel composite steel pipes is much lower than that of thick-walled pure stainless steel pipes and thick-walled pure copper pipes.
- Production process
In the production of stainless steel composite pipes, the composite steel pipe manufacturer must be required to select different corrosion-resistant alloy layers as the inner lined pipes according to the requirements of the chemical company's process flow. Most corrosion-resistant alloys (such as pure titanium,Nickel-based alloy, ordinary stainless steel, duplex stainless steel) can all be used as inner lining layer. But for Duplex stainless steel In other words, the difficulty of recombination is very high because the yield strength of duplex steel is relatively large and the elongation of break is small. If the process control is not accurate enough, it is very easy to crack during the recombination process. Duplex stainless steel has two metallographic structures: austenite and ferrite, so it resists chloride ion corrosion andStress corrosion crackingGreat performance over316L. In salt making or salt chemical companies, duplex stainless steel composite steel pipes have very good performance advantages.
Sinosteel Stainless Steel Pipe is the Manufacturer and Supplier of Stainless Steel Pipe and Special Alloy Pipe