The surface quality of the steel pipe is improved by removing the outer surface of the steel pipe with high-pressure water. With the market for hot-rolled seamless steel pipe on the outer surface of the increasingly high demand, the operating conditions of descaling water system problems are highlighted. Improvement measures: 1) Improve the water seal between the plunger and seal. The original plunger and seal letters between the seal life is short. At least once a week, or leakage of the system pressure and flow can not meet the production requirements. The original water seal is the material for the nylon plus graphite ring seal. Sealing material is too hard, deformation is small, leaking adjustment of the packing box water seal gland has no effect. The improved water seal material for the tetrafluoroethylene + graphite material + copper ring alternate combination of ring seal. Improved water seal life of up to 2 to 4 months, during which a little water leakage to adjust the packing box water seal can be. 2) To improve the structure of the check valve to improve the one-way valve sealing. The original one-way valve for the vertical one-way valve, the direction of water flow into the high, the seal between the valve core and valve seat for the plane seal, spool positioning and orientation by the valve cover. If the spool and the valve seat between the mechanical impurities, spool and seat Seal lax, while the valve cover and the stem easily deformed, the valve cover on the spool positioning guide down, between the valve core and the valve seat seal further Down until the system does not work properly. The improved one-way valve is a tubular one-way valve, the horizontal direction of water flow activities, sealing between the valve core and the valve seat for the cone seal. The spool has a guide rod along the axial direction, the spool has a strong spring with the spool to strengthen the one-way with the role of one-way guide with the spool and guide sleeve with the orientation of guidance is not chaos good, good sealing effect. 3) To improve the suction valve, drain valve and pump the seal between the spring. The original suction valve, drain valve and the seal between the pump body profile trapezoidal shape, the material is nylon. Deformation is very small, the sealing effect is poor. Benxi high-pressure water pump factory to improve suction valve, drain valve and the seal between the rubber material to rubber O-ring. The improvement of the sealing between the suction valve, the drain valve and the pump body solves the problem that the high-pressure water of the system goes into the low-pressure inlet end, destroys the pump body and forms the hornet's nest-type cylinder block; and solves the problem that the high- Water pipes, damaged piping and components. The original suction valve, drain valve spring material improved to 1Cr18Ni9Ti, to solve the suction valve, drain valve original spring due to lack of elasticity and rupture, resulting in high pressure water fleeing into the low-pressure water really a problem. Improved system conditions are not chaotic, suction, drain valve maintenance cycle from the original uniform week increased to about a month and a half. 4) To improve the life of the plunger. The original plunger often produces longitudinal scratches. The reason is mainly because the plunger in the high-speed reciprocating motion in the stuffing box with the friction function of the seal box, the outer surface of the plunger Ni60 plated Ni thick layer of 30μm plunger plunged into the longitudinal scratches significantly reduced.

Alloy steel casting process compared with carbon steel has the following characteristics: (1) According to the needs of the cast steel, the liquid steel purity, composition and pouring temperature, especially the control of trace element content, are required to achieve the specified value. This special steel continuous casting furnace must be equipped with refining equipment. (2) Mold should be used high-frequency, small amplitude vibration. (3) Selection of good performance and the protection of the whole process of pouring casting to ensure the quality of slab. (4) The best use of large capacity, deep melt pool, and build a retaining wall, the dam of the tank, give full play to the metallurgical function of the middle tank. (5) It should use the appropriate refractory materials to reduce consumption and improve the purity of steel. (6) The use of mold level automatic control to reduce surface fluctuations.

(1) Raw materials that coil, wire, flux. In the input before going through rigorous physical and chemical tests.  (2) Head-to-tail docking, the use of single-wire or double-wire submerged arc welding, rolled into steel after the adoption of automatic submerged arc welding. (3) Before forming, the strip after the flattening, cutting edge, planing, surface cleaning and transportation to the bending treatment.  (4) The use of electrical contact pressure gauge control the pressure on both sides of the conveyor cylinder pressure to ensure the smooth transport of strip.  (5) The use of external control or internal control roller molding. (6) The use of weld gap control device to ensure that the welding gap to meet the welding requirements, diameter, the wrong amount of margin and weld gap are strictly controlled. (7) Within the welding and welding are used in the United States Lincoln welding machine for single or double wire submerged arc welding, in order to obtain a stable welding specification. (8) Welded have been through the line of continuous automatic ultrasonic inspection instrument to ensure that the 100% of the spiral weld nondestructive testing coverage. If there are defects, automatic alarm and spray marks, so the production workers at any time to adjust the process parameters, the timely elimination of defects.  (9) Spiral steel pipe using air plasma cutting machine will cut into single pipe.  (10) Cut into a single pipe, the first of each batch of steel pipe to the first strict inspection system to check the mechanical properties of welds, chemical composition, melting conditions, steel pipe surface quality and non-destructive testing to ensure that the pipe process Qualified, can be formally put into production.  (11) The location of the weld on the continuous acoustic flaw detection mark, after manual ultrasonic and X-ray review, if there are defects, after repair, again after non-destructive testing until the defect has been confirmed to eliminate. (12) The welds of the strip butt welds and the pipes of the d-type joints intersecting the spiral welds are all examined by X-ray television or film inspection. (13) Pipe end machining, so that the end of vertical, groove angle and blunt edge to be accurately controlled. (14) Each pipe is subjected to a hydrostatic test and the pressure is radially sealed. Test pressure and time by the computer control of water pressure microcomputer control.

ERW steel pipe welding process is the use of high-frequency current generated skin effect principle to hot-rolled coil edge to the molten state, and then by mechanical extrusion method of welding. The steel pipe produced by this process will produce a white fusion line in the center of the weld. The heat affected zone on both sides of the fusion line will produce metal flow lines extending from the middle to the inner and outer surfaces. ERW steel pipe is used as a base metal welding material, so the performance of its weld metal base with a greater relationship. Common materials, the weld and base metal Charpy impact energy absorption test value is very small. On the contrary, there is a big difference in the high toughness of the material, the impact toughness was significantly worse than the base metal, but significantly better than the common materials of the weld. It can be seen that the impact toughness of the weld center of ERW steel pipe, even if the use of high toughness material, although the weld toughness is improved, but can not completely improve the weld center of the impact toughness.

In the design of the pressure pipe, pipe diameter is determined by the calculation, we must select the material pipe. The use of pipe materials for pressure pipe is based on the operating conditions of the medium (such as pressure, temperature) and the media characteristics of the decision.  Improper selection of materials, will result in a waste or buried accident risks. If you can use ordinary materials, pipe, pipe selection of more expensive materials, it increases the unnecessary investment in infrastructure. The use of acid-resistant stainless steel with carbon steel will directly affect the normal operation of the pressure pipe, and even leave the seeds. Therefore, the choice of pipe materials, designers must first understand the type of pipe, specifications, performance, use, it is best to investigate the pipe in other similar pressure pipe applications, and then in accordance with the following principles to determine the material pipe.