The uniformity of the wall of thick-walled straight-seam steel pipes will directly affect the later processing of parts. The wall of thick-walled straight-seam steel pipes cannot be controlled, which means that the overall steel pipe cannot be strictly controlled. Small and medium-sized steel, wire rods, steel bars, medium-diameter thick-walled steel pipes, steel wires steel wire ropes, etc., can be stored in a ventilated material shed, but the top is covered with a thatch and the bottom is padded. Some small thick-walled steel pipes, thin steel plates, steel strips, silicon steel sheets, small-diameter or thin-walled thick-walled steel pipes, various cold-rolled, cold-drawn thick-walled straight-seam steel pipes, and high-priced, corrosive metal products can be stored in the warehouse. Choose a suitable site and warehouse for storing thick-walled steel pipes. The site or warehouse should be clean and well-drained, away from factories and mines that produce harmful gases or dust. The warehouse should be selected based on geographical conditions. Generally, an ordinary closed warehouse is used, that is, a warehouse with a wall on the roof, tight doors and windows, and a ventilation device. The warehouse is required to be ventilated on sunny days and closed to prevent moisture on rainy days, and a suitable storage environment must be maintained at all times.
Thick-walled straight seam steel pipes are rolled from steel plates. After rolling, they need to be welded. Generally, there are three steps of welding: pre-welding, external welding, and internal welding. After welding is completed, flaw detection is required. The steel pipes for export need to be beveled, painted, and capped. Length processing according to customer’s requirements. Generally divided into fixed length and indefinite length. The main implementation standards are GB/T3091, GB/T9711, and API. Among them, GB/T9711 is divided into three parts: steel, B-grade steel, and C-grade steel. Thick-walled straight seam steel pipe is a kind of steel pipe used in oil and gas transmission pipelines with large usage and high reliability. Submerged arc welding straight seam steel pipe unit, the forming unit types include UOE, RBE, JCOE, etc. The main production process is qualified steel plate – plate edge chamfering – plate edge pre-bending – forming – JCOE forming – continuous welding of steel pipe seams – arc welding of inner pipe seams – submerged arc welding of outer pipe seams – rounding and straightening – pipe ends Chamfering and trimming – weld wave inspection – unqualified weld bead repair – weld bead X-ray inspection – hydraulic pressure test – weld bead wave inspection – unqualified weld bead repair – pipe inner surface drying treatment – pipe inner surface rust removal treatment – pipe inner surface Anti-rust coating treatment – rust removal treatment on the outer surface of the pipe – anti-rust coating treatment on the outer surface of the pipe – finished product.
The service life of a ship is generally about 20 years. There are many conventional systems, mainly including bilge water, ballast, drainage, injection, domestic water, fire protection, domestic sewage, air, measurement, cargo oil, cabin cleaning, ventilation, inert gas, heating, tank washing, foam fire extinguishing, water sprinkling, evaporation gas, liquid level telemetry, valve remote control, and other systems. Special ships also include special systems for transporting liquefied petroleum gas (LPG), liquefied natural gas (LNG), and other special systems. The service life of straight seam steel pipes in marine engineering can be at least 40 years. In addition to conventional systems in offshore engineering, there are also special drilling equipment systems, crude oil, liquefied petroleum gas, and liquefied petroleum gas processing process systems. Statistics show that the annual consumption of large-diameter straight seam steel pipes for ships reaches 5 million tons, about 500,000 pieces. The standards are GB, YB, and CB, and 70% of the steel pipes are connected. Just one 300,000-ton ultra-large oil tanker uses tens of kilometers of steel pipes and pipe fittings. The amount of steel pipes alone (including) is about 1,000-1,500 tons. Of course, compared to the 40,000 tons of steel pipes used in the hull structure, the amount of steel pipes used is still relatively limited. Also, consider that there are multiple ships to be built of the same type, and there are many other ships. A 300,000-ton ultra-large FPSO has more than 40,000 pipes and a length of more than 100 kilometers, which is 3-4 times that of the same tonnage. Therefore, the shipbuilding industry has become a large user of the steel pipe industry. For the application of straight seam steel pipes in marine engineering, in addition to the above-mentioned conventional systems and special systems, straight seam steel pipes are widely used in many structures, such as jackets, underwater steel piles, riser casings, mooring brackets, helicopter platforms, towers, etc.
This type of straight seam steel pipe has many specifications and high-quality materials. It has the same diameter, different diameters, different wall thicknesses, and a large number of Y, K, and T-shaped pipe nodes. Such as jackets, steel piles, wellhead water isolation sleeves, etc., most of which are large-diameter straight-seam steel pipes, which are generally rolled from steel plates. In addition to the size requirements for straight seam steel pipes in marine engineering. It also has high requirements for its corrosion resistance. Since the steel pipe has been in contact with water and various media in the water for a long time, the corrosion of the steel pipe is very serious. Therefore, the straight seam steel pipe must be treated with anti-corrosion technology before use. In the early days of the steel pipe industry, there were many tricks, but now people are more proficient in this industry. If the wall thickness of the steel pipe is not enough, use the gate method. If the mouth end of the steel pipe is shielded with a hammer, it will look thicker, but when measured with instruments, it will be thicker. Will be revealed. A straight seam is used as a seamless steel pipe. The straight seam weld is less than a longitudinal weld. The entire steel pipe is polished with a machine, commonly known as polishing. It looks like there is no gap to act as a seamless steel pipe.
In the production process, straight seam steel pipes need to use a product, that is, glass lubricant. Before the use of glass lubricants, they were produced with graphite, because this product was not available in the market at that time. Therefore, graphite can only be used as a lubricant, but after long-term use, everyone will find some problems, that is, the heat transfer efficiency of graphite is very high, and the heat insulation effect is also very poor, so when working It will cause the mold to heat up very quickly, which will easily cause the straight seam steel pipe to wear, so that the product cannot be used for a long time. Therefore, manufacturers have been looking for a product that can replace graphite, that is, glass lubricants, but why should they be used? That is because the trolley furnace has many advantages. The first is that the heat transfer efficiency is relatively low so It plays the role of heat preservation and can also extend the use time of the equipment.
Post time: Jan-16-2024