Ductile iron pipe is a kind of pipe material widely used in water supply, drainage, gas transmission and other fields. It has the characteristics of high strength, corrosion resistance and long service life. The diameter range of DINSEN ductile iron pipe is DN80～DN2600 (diameter 80mm～2600mm), generally 6 meters and can also be customized. Pressure level: usually divided into T type (low pressure), K type (medium pressure) and P type (high pressure). Click to get the catalog of ductile iron pipes.
For the connection methods of ductile iron pipe system, DINSEN summarizes them as follows:
1. T-type socket connection: It is a flexible interface, also called a slide-in interface, which is a common interface for domestic ductile iron pipes. The contact pressure between the rubber ring and the socket and the spigot forms a seal for the fluid. The socket structure takes into account the positioning and deflection angle of the rubber ring, can adapt to a certain foundation settlement, has a certain earthquake resistance, has the characteristics of simple structure, easy installation and good sealing, etc. Most water supply ductile iron pipes on the market use this interface.
Specific steps: 1. Clean the socket and spigot. 2. Apply lubricant to the outer wall of the spigot and the inner wall of the socket. 3. Insert the spigot into the socket to ensure it is in place. 4. Seal with a rubber ring.
2. Self-anchored socket connection: It adopts a T-type interface sealing structure, which is used in situations where the thrust of the water flow at the bend of the pipe is too large, or the settlement is too large, which easily causes the interface to fall off. Compared with the T-type interface, the welding ring, movable opening retaining ring, special pressure flange and connecting bolts welded on the spigot end of the pipe are added to make the interface have better anti-pullout ability. The retaining ring and the pressure flange can slide, so that the interface has a certain axial expansion and deflection ability, which can be used when the pier cannot be set.
3. Flange connection: By tightening the connecting bolts, the flange squeezes the sealing ring to achieve interface sealing, which is a rigid interface. It is often used in special occasions such as valve accessory connections and connections of different pipes. The advantages are high reliability and good sealing. It is suitable for situations where the pipe diameter is large or the pipe length is long, and it is also suitable for scenes where the pipe connection and disassembly requirements are frequent. However, if it is buried directly, there is a risk of corrosion on the bolts, and manual operation has a greater impact on the sealing effect.
Specific steps: 1. Install flanges at both ends of the pipe. 2. Add a sealing gasket between the two flanges. 3. Fasten the flange with bolts.
4. Arc welding: Suitable welding rods such as MG289 welding rods can be selected for welding, and the strength is higher than that of cast iron. When using arc hot welding, preheat 500-700℃ before welding; if a nickel-based alloy welding rod with good plasticity and high crack resistance is selected, arc cold welding can also be used, which has high productivity, but the arc cold welding has a fast cooling speed, and the weld is prone to white mouth structure and cracks.
5. Gas welding: Use RZCQ type welding wire, such as magnesium-containing ductile iron welding wire, use neutral flame or weak carburizing flame, and slowly cool after welding.
Specific steps: 1. Clean the pipe end. 2. Align the pipe end and weld. 3. Check the quality of the weld.
6. Threaded connection: A ductile iron pipe with threads on one end is connected to a joint with matching threads. It is suitable for applications with smaller diameters and lower pressures. It is relatively easy to install and disassemble, but its sealing performance is relatively limited, and it has high requirements for thread processing accuracy and installation operations.
Specific steps for other connection methods: 1. Process external threads at the pipe end. 2. Use internal thread joints to connect. 3.Seal with sealant or raw tape.
7. Elastic sealing ring connection: Install an elastic sealing ring at the end of each pipe section, and then push the two pipe sections in and connect them together through a thrust connector. The sealing ring ensures the sealing performance of the connection and is suitable for pipes with smaller diameters.
8. Rigid waterproof wing ring connection: Weld the water stop wing ring on the ductile iron pipe, and directly cast it into one piece during the construction of reinforced concrete walls. It is often used to connect ductile iron pipes for drainage with walls such as inspection wells.
In short, the connection method of ductile iron pipes can be selected according to the construction scenario. Specifically, the socket connection is suitable for underground pipes, the flange connection is suitable for occasions that require frequent disassembly, the threaded connection is suitable for small-diameter pipes, the welding connection is suitable for high-pressure and high-temperature environments, and the mechanical connection is suitable for temporary or emergency situations.
Contact DINSEN for your customized ductile iron pipe connection solution
Post time: Feb-07-2025