The difference of hot dip galvanized square tube and cold galvanizing square tube

Galvanized square tube in two ways: hot-dipped galvanized square pipe and galvanized square tube into two categories. Galvanized square pipe with wet, dry, lead, zinc, oxidation reduction method. Different methods of hot dip galvanized steel pipe main difference in the acid leaching after cleaning, the method used to improve the surface activation of galvanized pipe quality. Are mainly the production of dry and oxidation-reduction method, which is characterized in Table. Electro-galvanized zinc layer of the surface is very smooth and dense, homogeneous; has good mechanical properties and corrosion resistance; hot dip galvanized zinc consumption lower than 60% to 75%. Galvanized of the technical complexity, but the single-sided coating, inside and outside surface of the coating thickness of the different double-sided coating, and thin-walled tube galvanized h ave to be using this method.


Hot-rolled seamless steel pipe defect


1 uneven wall thickness
Features: steel pipe in the same section of uneven thickness, the big difference between the maximum wall thickness and minimum wall thickness.

2 wall thickness of ultra-poor
Features: pipe wall thickness one-way ultra-poor, ultra-positive deviation is called extra-thick wall thickness; the negative deviation is called ultra-thin wall thickness.


What is large-diameter hot-expanding seamless steel pipe?

Large-diameter hot-expanding seamless steel pipe product, as smelting, rolling main line extension, he used the "medium frequency heating, hydraulic push system" Expanding process, our factory has three advanced thermal expansion of pipe production line can be a variety of to 820mm diameter steel pipe expansion following a variety of specifications. In recent years, large-diameter seamless steel pipe factory has formed a variety of full scale structural systems in the oil and gas pipelines, building structures, petrochemical and other industries, to specifications, superior quality, quick delivery, reasonable price and other advantages by industry praise. Products are widely used in aerospace, chemical, construction, food, industrial control, medical, nuclear power plant, oil and gas development and production, transportation and seabed exploration and other fields.

coil tube heat

Coil volume heat exchanger is very common on board applications, mainly used for heating the deep tank body storage and some crude oil, edible oil, grease and syrup goods. These fluids at room temperature because the viscosity is too high can not handle the steam coil to raise the temperature of the liquid, to reduce their viscosity so that it can be pumped.


Requirements of sewage pipe corrosion

Sewage pipes buried under the city's characteristics, pipeline coating should meet the following basic requirements:

① has good chemical resistance;

② good insulating properties and density, electrochemical, and to prevent stray current corrosion;


The defect of buried pipeline

Corrosion of buried pipelines in the urban sewage treatment project is mainly soil erosion, which is characterized by scattered piping, soil conditions are very complex, so the corrosion mechanism is very complex.

Soil erosion and soil in the salt, water, oxygen and the electrochemical corrosion of steel pipe composition, microbial erosion. As the urban underground electrical facilities, cable is more dense, stray current corrosion is more serious, even through the pipeline near the plant may be acid or alkaline media of chemical corrosion.


LSAW steel pipe rust method

In the oil and gas pipeline anti-corrosion construction process, LSAW steel pipe anti-corrosion surface treatment is to determine the life of one of the key factors, it is LSAW steel pipe anti-corrosion layer and whether the combination of a solid premise. The study of professional organizations, in addition to the life of the coating depends on the type of coating,Coating quality and construction of environmental factors, LSAW steel pipe coating surface treatment of life-span of about 50%, therefore, should be strictly in accordance with standard coating the surface of LSAW steel pipe requirements, continuous improvement straight seam steel surface treatment method,LSAW steel pipe are mainly the following methods in addition to embroidery


SSAW steel pipe and LSAW steel pipe

50 to 60 years, spiral steel pipe(SSAW steel pipe) in the oil and gas pipelines in the widely used, 70 to 80 years by the LSAW steel pipes and ERW steel pipes of serious challenges, since the world is basically in the oil and gas pipeline is no longer used in the spiral steel, many large international Shiyou Gong


LSAW steel pipe symbol and acceptance

An outer diameter less than 36mm of LSAW steel pipe and shaped cross-section perimeter is less than 150mm of LSAW steel pipes, from time to print in mind.

2 outside diameter not less than 36mm of LSAW steel pipe and the cross-section shaped perimeter not less than 150mm of LSAW steel pipe, straight seam should be at each end of the pipe ends are printing, stamping, roll printing, stamp or mark paste . Mark should be clear and obvious, not falling. Mark should include the steel grade, the product rules


Identification of steel pipe materials fracture

Chemical composition of different steel pipe materials, the fracture characteristics also varies. The fracture characteristics observed by the naked eye. Steel materials can be identified in general, this method is called fracture identification method.