① appearance inspection: artificial lighting conditions, standards, experience, rationality, tube rotation. ② non-destructive testing. Ultrasonic testing of ultrasound.

Boiler pickling steps are as follows First, start the pickling, boiler economizer, fill the inner cylinder and soften the water wall.

Pipe shall not be directly piled on the ground, steel or concrete surface, the first layer of steel pipe from the ground distance of not less than 0.20m. Avoid pipes damp, dust and pollution, steel pipe (or pipe) should be placed in dusty and humid place, the ends of the pipe must be protected with plastic or paper bag, etc., to prevent dust from entering.

Pipe bending strength mortar coating test tube diameter, easy bending pipe, smooth and easy. Hour diameter easy to bend. It is considered that the coating of the pipe is liable to cause a curved mortar coating due to peeling of the coating. Cement mortar lining and ordinary cement with a certain thickness of sand, admixture, according to the ratio of design, made of mortar mixture, through special construction machinery and equipment, applied to the wall, the formation of a certain thickness of the mortar coating, cured lining. Cement mortar lining, relying on its own strength with the support of the wall, the structure is uniform, dense, hard, solid, and then brushing the surface of epoxy mortar, water roughness coefficient can be reduced. Cement mortar lining is not only a simple physical barrier barrier performance, but by the chemical properties of cement mortar lining to protect the pipeline.

High-pressure steel pipe for the manufacture of steel pressure vessels and pipe quality carbon steel, alloy steel and stainless steel seamless steel pipe.

Resistance welding is the workpiece through the electrode pressure, the use of current through the resistance thermal contact surface and the adjacent area of the connection welding.

Simple, easy to use, economical and practical, while adding high-performance corrosion inhibitors, corrosion inhibitors to prevent metal corrosion and hydrogen embrittlement, inhibiting the generation of fog. Especially for small complex parts, the situation should not be oiled, better than similar products in the market.

Seamed pipe is the strip or plate bent into a circular, square and other shapes, and then welded into the surface of the connecting pipe. Pipe is the use of steel or steel strip.

The unqualified mechanical properties of seamless steel pipe mainly in its low elongation, yield point is not obvious, the mechanical properties of the above unqualified products metallographic examination and found that the cold-drawn tube spherical pearlite and fine grain ferrite .

1, metal pipe, rod, wire testing, do not need to contact, do not need the coupling medium. Therefore, test speed, easy to automate the test, especially for online P capture.

Welded pipe joints suitable medium: oil, water, gas and other non-corrosive or corrosive media, welding seals require more flexible steel pipe specifications, the pipe after the weld has a strong connection, good sealing performance. It has been widely used in oil refining, chemical, light industry, textile, defense, metallurgy, aviation, shipbuilding and other systems, but also for a variety of mechanical engineering, machine tools and other hydraulic transmission lines. When the bite-type pipe fittings can not meet the needs of production, as well as the case of corrosive, consider giving priority. Welded pipe fittings manufacturing standards

Seamless steel pipe and longitudinal welded pipe compared to the following: 1, high precision Diameter and wall thickness deviation, straight seam welded pipe smaller than the seamless steel pipe. This is because steel pipe rolling and tube forming are easy to control and therefore have high dimensional accuracy.

Pipe surface roughness is the machined surface with small spacing and small valley irregularities. The distance between two wave crests or two troughs (pitches) is small (less than 1mm) and the naked eye is hard to distinguish, belonging to the geometrical error of the microstructure. The greater the surface roughness, the smoother the surface. The size of the surface roughness, the mechanical parts have a great impact on the performance.

Hot-rolled seamless steel billet can be forging blank, billet, slab, billet centrifugal casting. Short or long blank blanks are peeled off in the machine shop, sawing, drilling deep holes, back turning and chamfering into the extrusion line.

Weld and seamless pipe poor Concentricity: Manufacturing Process for Seamless Pipe A hole of stainless steel billets are fired at a temperature of 2200 ° F. At this temperature, the tool steel becomes soft and stamped and spirally drawn in Hong Kong. Uneven wall thickness, high eccentricity. As a result, ASTM allows seamless pipe wall thicknesses to differ significantly from those of pipe joints. Steel pipe fittings made of precision cold rolled sheet (4-5 feet per foot width). Cold-rolled sheets typically have a wall thickness of 0.002 inch. The sheet is cut into wide πD, where D is the tube outside diameter. Slit pipe wall thickness tolerance is small, and the entire circumference of the wall thickness is very uniform.

Galvanized iron pipe is generally used for water lines, it is anti-corrosion zinc impregnation. GI pipe is "galvanized iron pipe." Material MS is mild steel and GI is hot dip galvanized steel. Commonly used in water pipes on the galvanized iron pipe.

Straightening machine is a metal profile, bar, pipe, wire and other straightening equipment. Straightening roller straightening machine, to make it straight. There are usually two rows of straightening rollers in varying numbers. There are also two roll straighteners that rely on the variation of two roll angles (intermediate concave hyperbolic rolls) to straighten at different diameters. The main pressure straightening machine, balancing roller straightening machine, straightening machine, rotating straightening machine.

Density is one of the many properties of steel. It is calculated by dividing mass by volume. Steel has many different shapes. Density is calculated by dividing mass by volume. Carbon steel has a density of about 7.85 grams per cubic centimeter (0.284 pounds per cubic inch).

DIN 30670 is a polyethylene coating on steel pipes and fittings. Requirements and testing.

Hydrostatic Pressure Test Static method is used to measure the measurement index of rock deformation.

ERW is the acronym for the first letter, resistance welding. ERW pipe and submerged arc welding pipe are significantly different, the use of non-pressurized filler metal welding, the weld is no other ingredients, relying on the skin effect of high frequency current and proximity effects, instant heating plate edge squeeze roll extrusion forging of welded joints Welding temperature. High-quality steel pipe welds require on-line or off-line heat treatment, weld zone refinement, quality ERW pipe welds and base metal toughness can reach the same level, which is submerged arc welding process can not be achieved.