Hebei Haihao Group

  • The function of sandblasting

    The function of sandblasting

    There are many manufacturing processes of producing pipe fittings, like cutting end bevels, heat treatment and sandblasting etc. Every process plays a very important role.The following is a brief production about the function of sandblasting: 1.The cleanin ...
  • What's the small-diameter welded pipe?

    What’s the small-diameter welded pipe?

    Small diameter welded pipe, also known as small diameter welded steel pipe, is a steel pipe welded by steel plate or strip steel after crimping. The production process of small-diameter welded pipe is simple, the production efficiency is high, the varietie ...
  • What's the hot dip galvanizing process of flange?

    What’s the hot dip galvanizing process of flange?

    The process of hot galvanizing of flange is acid pickling assisted plating drying hot dip galvanizing separation cooling passivation. Customers who purchase flange will be galvanized according to the requirements of the use of the flange. Hot dip galvanizi ...
  • What are the differences between forged flange and cast flange?

    What are the differences between forged flange and cast flange?

    The cast flange has the advantages of accurate blank shape and size, small processing capacity and low cost, but it has casting defects (porosity, cracks and inclusions); the streamline of internal structure of casting is poor (even worse if it is a cuttin ...
  • Production process of seamless steel pipe and welded pipe

    Production process of seamless steel pipe and welded pipe

    Stainless steel pipes are usually divided into two categories: seamless pipes and seam welded pipes. In the production process, the required equipment is also different. The difference can be seen from the production process flow chart of the two: In the p ...
  • What's the anti-corrosive steel pipe lined with cement mortar?

    What’s the anti-corrosive steel pipe lined with cement mortar?

    Anti-corrosive steel pipe lined with cement mortar refers to the anti-corrosive and wear-resistant treatment of cement mortar inside the pipe body. As the steel pipe lined with cement mortar is filled with concrete, it can absorb a lot of heat energy. Ther ...
  • What are the welding methods of long-distance pipeline?

    What are the welding methods of long-distance pipeline?

    Long-distance pipeline need some welding methods,the process as follows: First, manual welding (1) Arc welding of electrodes is sensitive and cumbersome, and has strong conformability. At the same time, due to the continuous improvement of electrode perfor ...
  • What is slotted pipe?

    What is slotted pipe?

    Slotted drain pipe is a practical, aesthetically pleasing drainage inlet product for the efficient removal of surface water and sheet flow on streets and highways. Slotted Drain Pipe is fabricated by welding a narrow section of grating in a continuous slot ...
  • What's post weld heat treatment (PWHT)?

    What’s post weld heat treatment (PWHT)?

    Recently,some client feel query and ask “is there any PWHT requirement?” for some prefabrication.What’s post weld heat treatment (PWHT)? Broadly speaking, post weld heat treatment is the heat treatment of the welded area or welded compone ...
  • What's the cooling methods of forgings after forming?

    What’s the cooling methods of forgings after forming?

    There are the cooling methods of common forgings after forming: In order to prevent the surface cracking of high carbon steel and high alloy steel, it is necessary to stack cooling, furnace cooling, sand embedding cooling or baking slow cooling in front of ...
  • Defects and preventive measures of forgings during heat treatment and quenching

    Defects and preventive measures of forgings during heat treatment and quenching

    Oxidation and decarburization When steel is heated, there is a layer of brittle iron scale on the surface is called oxidation; decarburization refers to the phenomenon that the carbon content on the surface decreases. Oxidation and decarburization will red ...
  • Introduction of forging heat treatment process

    Introduction of forging heat treatment process

    Forging heat treatment process regulations (process cards) and heat treatment forging schedules are necessary process documents for guiding heat treatment production. In addition, there should be temporary process notices, heat treatment process codes, hea ...
  • The heat treatment process of steel pipes

    The heat treatment process of steel pipes

    Why should we have heat treatment on steel pipes? What are the main types of steel pipes’ heat treatment process? Heat treatment is one of the important processes in the production process of steel pipes. It plays an important role in exploring poten ...
  • Introduction and application of normalizing heat treatment process

    Introduction and application of normalizing heat treatment process

    Normalizing is a heat treatment process in which steel parts are heated to 30-50 ℃ above the critical temperature and cooled in static air after holding for appropriate time. The main purpose of normalizing is to refine the microstructure, improve the prop ...
  • Heat treatment method of forgings after forging

    Heat treatment method of forgings after forging

    The purpose of heat treatment of forgings after forging is to adjust the hardness of the forgings and improve the cutting performance; eliminate the internal stress after forging; refine and uniform the coarse grains during the forging process to prepare t ...
  • What you need to know about 3PE anti-corrosive steel pipe?

    What you need to know about 3PE anti-corrosive steel pipe?

    In China,3PE anticorrosive steel pipes have been applied in oil and gas systems,nearly 4,000 kilometers of the national key project West-East Gas Pipeline have used 3PE anti-corrosion steel pipes. We have also exported a lot of 3PE coated steel pipes to ma ...
  • Coating types of steel water transmission pipe and  fittings under AWWA standard

    Coating types of steel water transmission pipe and fittings under AWWA standard

    For the steel water transmission pipes and fittings,the coatings are necessary to use in order to prolong the service life of products.The often used standard is AWWA standard.There are several coating types for steel pipes and fittings under this standard ...
  • How does the coal tar enamel coating or lining protect the pipeline?

    How does the coal tar enamel coating or lining protect the pipeline?

    Sometimes clients ask for the coal tar enamel coating or lining for the pipeline.We all know that coating or lining could protect the pipeline from corrosion and expand the service life.But how does it works? The coal tar pitch, which forms the basis for t ...
  • Pipeline coatings used in high temperature

    Pipeline coatings used in high temperature

    Global trends in pipeline technology and pipeline coatings are in part dictated by where the oil and gas reserves are located. These reserves are becoming increasingly difficult to find. Producers are looking further afield and often find the reserves are ...
  • What causes the corrosion of pipe fittings?

    What causes the corrosion of pipe fittings?

    Corrosion of pipe fittings refers to the degradation and destruction of metal materials caused by the chemical and electrochemical action between the metal material surface and the environmental medium. In petroleum pipelines, common corrosion is mainly ca ...