What are the process flows for API 5L welding steel pipes?

　　API 5L welding steel pipes often uses the Shielded Metal Arc Welding (SMAW) technique, commonly called stick welding. This method uses a stick-shaped electrode to generate an electric arc that melts the metal during welding. The welder uses a flux-coated electrode to protect the weld metal and prevent atmospheric contamination.

　　1. Process flow Installation preparation - groove rolling - hole opening, installation of mechanical tees and crosses - pipeline installation - system pressure test.

　　2. Installation preparation

　　1. Check the hole opening machine, groove rolling machine, and pipe cutting machine to ensure safe use.

　　2. Preparation of materials and tools, including pipes, steel tape measures, wrenches, vernier calipers, spirit levels, lubricants, wooden hammers, scaffolding, etc.

　　3. Install the support and hanger for the pipe to be installed according to the design requirements.

　　Welded steel pipe installation process

　　3. Groove rolling

　　1. Use a pipe cutting machine to cut the steel pipe to the required length, and use a spirit level to check the cut section to ensure that the cut section is perpendicular to the center axis of the steel pipe. If there are burrs on the cut, use a grinding wheel to grind it smooth.

　　2. Set the steel pipe that needs to be grooved on the groove rolling machine and the groove rolling machine tail frame, and use a spirit level to level it so that the steel pipe is in a horizontal position.

　　3. Place the processed end section of the steel pipe close to the groove rolling machine, so that the central axis of the steel pipe is perpendicular to the roller surface.

　　4. Press down slowly. Use the jack to make the upper pressure wheel close to the steel pipe, start the groove rolling machine, and make the roller rotate one circle. At this time, pay attention to whether the section of the steel pipe is still close to the groove rolling machine. If not, adjust the pipe to horizontal. If it is close, slowly press down the jack to make the upper pressure wheel roll the steel pipe evenly to the predetermined groove depth.

　　5. Stop the machine, check the groove depth and width with a vernier caliper, and after confirming that it meets the standard requirements, unload the jack and take out the steel pipe.

　　Welding steel pipe installation process

　　Fourth, open the hole. Install mechanical tees and crosses

　　1. Draw ink lines on the steel pipe to determine the opening position of the joint branch pipe.

　　2. Fix the chain hole opening machine at the predetermined opening position of the steel pipe. 3. Start the motor, turn the hand wheel, and slowly move the drill bit close to the steel pipe. At the same time, add lubricant to the drill bit to protect the drill bit and complete the drilling of the steel pipe.

　　4. Stop the machine, shake the hand wheel, open the chain, remove the drilling machine, clean the drilled metal blocks and the residue at the drilling site, and use a grinder to grind the hole smooth.

　　5. Put the clamp on the steel pipe, pay attention to the mechanical tee should be concentric with the hole, the gap between the rubber sealing ring and the hole is uniform, and tighten the bolts in place.

　　6. If it is a mechanical four-way, be sure to ensure that the holes on both sides of the steel pipe are concentric when drilling, otherwise when the installation is completed, the rubber ring may rupture and affect the water flow area.

　　Welded steel pipe installation process

　　V. Pipeline installation, according to the principle of installing large diameter, main pipe, and riser first, and then small diameter and branch pipe. During the installation process, it must be installed continuously in sequence, and it cannot be installed in a jump or segmented manner, so as to avoid difficulties in connecting segments and affecting the overall performance of the pipeline.

　　1. Fix the steel pipe on the support and hanger, and put the undamaged rubber seal ring on the end of one steel pipe.

　　2. Insert the other steel pipe with lubricant applied around the end into the rubber seal ring, and rotate the rubber seal ring so that it is located in the middle of the interface.

　　3. Install the upper and lower clamps on the outside of the rubber seal ring, and send the convex edge of the clamp into the groove, press the upper and lower clamp ears tightly, and bolt on the clamp screw hole position and tighten the nut evenly and alternately. Use a wooden hammer to hammer the clamp during the process of tightening the nut to ensure that the rubber seal ring will not wrinkle. The convex edge of the clamp must be stuck in the groove around the entire circumference.

　　4. Add support brackets to the pipe within 500mm of the rigid clamp joint.

　　5. System pressure test After the pipeline is installed, the system pressure test should be carried out. Before the system pressure test, it is necessary to fully check whether all installation parts, fixed brackets, etc. are installed in place. The installed pipeline may sag. If the sagging arc is large, a bracket can be added; if the arc is small, the arc will naturally disappear when the pressure in the pipeline increases.facebooklinetwitterwhatsapppinteresttumblrlinkedin.

　　API 5L Welded steel pipe refers to a steel pipe with a seam on the surface that is made by bending steel strips or steel plates into round, square and other shapes and then welding them. The blank used for welded steel pipes is steel plates or strip steel.