Advantage & Disadvantage of Carbon Steel Tube Sheets

Tube sheet refers to the plate used for supporting and protecting pipelines. Pipelines are usually connected to the tubesheet through mechanical fixation or welding after drilling. In addition to serving as a fixing function, the pipe plate can also withstand the fluid and pressure inside the pipeline, reducing vibration and damage during operation. Carbon steel tube sheet, as a common tube sheet material, has a wide range of applications.

Carbon Steel Tube Sheets

 

 

Carbon steel tube sheets are mainly composed of iron and carbon, which contain a high proportion of carbon elements, usually between 0.2% and 2.1%. In addition, it may also contain small amounts of elements such as manganese, silicon, and phosphorus, which can improve the strength and corrosion resistance of carbon steel plates. Here are some main advantages and disadvantages of carbon steel pipe sheets:

Carbon Steel Tube Sheets

 

Advantages:

1. High cost-effectiveness: Carbon steel, as a common and economical material, is more affordable compared to other high alloy materials, making carbon steel pipe sheets the preferred choice in many applications.

 

2. High strength: Carbon steel is a type of steel with high strength, and its tensile strength is usually between 400-550MPa. This enables carbon steel plates to have high strength and rigidity under heavy loads and high pressures, enabling carbon steel pipe plates to maintain stability and reliability in high temperature and high pressure environments.

 

3. Good wear resistance: Carbon steel plates can achieve higher hardness and good wear resistance after heat treatment. Therefore, in some situations where wear resistance is required, carbon steel plate is the preferred material.

 

4. Easy to process and weld: Due to its low carbon content, carbon steel plates have good plasticity and weldability, and can be processed through various methods such as cold processing and hot processing. This makes the manufacturing and installation process of carbon steel pipe sheets relatively simple and efficient, reducing production costs and time.

 

5. Good environmental performance: Compared to other materials, carbon steel plates have better environmental performance. It can be recycled and reused to reduce resource waste and also reduce environmental pollution.

 

 

 

 

Disadvantages:

1. Easy to corrode: Carbon steel plates are prone to rusting, which is one of their biggest drawbacks. Due to the high content of iron in carbon steel plates, rust will occur when they react with oxygen in the air. This not only affects the appearance, but also leads to corrosion and damage to the surface of the board. Compared to stainless steel and other high alloy materials, carbon steel is more prone to corrosion in corrosive environments such as humidity, acidity, and alkalinity, which may lead to damage and shortened lifespan of the tube plate. To address corrosion issues, surface coatings or the use of anti-corrosion coatings can be used to enhance the corrosion resistance of carbon steel pipe sheets.

 

2. Not suitable for high temperature and strong acid environments: Carbon steel has lower temperature and acid resistance than high alloy materials, so in some applications that require high temperature or acidic media, carbon steel pipe sheets may not be suitable. This drawback can be avoided by welding other alloy materials to alter the performance of the contact surface.

 

3. Heavy weight: Compared to some lightweight alloy materials, carbon steel pipe sheets are relatively heavy, which may increase installation and maintenance difficulties.

 

 

In summary, carbon steel pipe sheets have advantages such as high cost-effectiveness, high strength, and ease of processing. However, their corrosion resistance, temperature resistance, and weight need to be evaluated based on specific application environments, and suitable materials should be selected to meet the requirements.

What Are The Applications of Industrial Rubber Casters?

Industrial rubber casters play a pivotal role in various sectors due to their versatility, durability, and reliability. Among the diverse range of caster wheels available in the market, medium duty 3" PVC rigid caster wheels, swivel industrial rubber cast iron casters, and cast iron core PU caster wheels stand out for their exceptional performance and applications. Let's delve into the diverse applications of these industrial rubber casters:

 

Medium Duty 3" PVC Rigid Caster Wheels:

Medium duty 3" PVC rigid caster wheels are designed to withstand moderate loads while offering excellent maneuverability and stability. These caster wheels find applications in industries where mobility and durability are paramount, such as:

 

Warehousing and logistics: They are extensively used in carts, dollies, and material handling equipment for transporting goods within warehouses and distribution centers.

 

Retail environments: Medium duty PVC rigid caster wheels are employed in retail display racks, utility carts, and shelving units, facilitating smooth movement of merchandise and supplies.

 

Hospitality industry: These caster wheels are utilized in hotel housekeeping carts, laundry carts, and food service trolleys, ensuring efficient service delivery without compromising on durability.

 

Swivel Industrial Rubber Cast Iron Casters:

Swivel industrial rubber cast iron casters offer exceptional maneuverability and load-bearing capacity, making them ideal for heavy-duty applications across various industries. Some notable applications include:

 

Manufacturing and production facilities: These casters are integral components of machinery and equipment used in manufacturing processes, providing mobility and flexibility in production lines.

 

Automotive industry: Swivel industrial rubber cast iron casters are utilized in automotive repair shops and manufacturing plants for moving heavy vehicle components and assemblies.

 

Construction sites: They are employed in scaffolding, tool carts, and equipment stands, facilitating easy movement of construction materials and tools across job sites.

 

Cast Iron Core PU Caster Wheel:

Cast iron core PU caster wheels combine the strength of cast iron with the resilience of polyurethane, offering superior load-bearing capacity and shock absorption. They find applications in various industries, including:

 

Aerospace and aviation: These caster wheels are used in aircraft maintenance trolleys, ground support equipment, and aerospace manufacturing facilities, ensuring smooth and safe movement of heavy components.

 

Healthcare sector: Cast iron core PU caster wheels are integral to medical equipment such as hospital beds, patient lifts, and mobile medical carts, providing stability and maneuverability in healthcare environments.

 

Food processing industry: They are employed in food processing equipment, bakery racks, and catering trolleys, meeting stringent hygiene standards while withstanding heavy loads and frequent washdowns.

 

In conclusion, industrial rubber casters, including medium duty PVC rigid caster wheels, swivel industrial rubber cast iron casters, and cast iron core PU caster wheels, serve a wide range of applications across diverse industries. Their durability, maneuverability, and load-bearing capacity make them indispensable components in material handling and mobility solutions, contributing to increased efficiency and productivity in various workplace environments.

Exploring Water Ripple Metal Sheets Where Does the Magic Lie?

In today's design and architectural realm, water ripple metal sheets have become a highly favored material. Not only do they bring a unique aesthetic to buildings, but they also imbue spaces with a sense of dynamism and modernity. In this article, we delve into the various uses, advantages, and innovative applications of water ripple metal sheets.

Water Ripple Metal Sheets 

The Wonders of Water Ripple Metal Sheets

Visual Impact: The distinctive texture of water ripple metal sheets offers endless possibilities for architecture and design. When light reflects off the surface of the metal sheet, it creates stunning light and shadow effects, making the entire space vibrant and intriguing.

 

Durability: Metal sheets possess excellent weather resistance and corrosion resistance, making them an ideal choice for both outdoor and indoor environments. Whether exposed to sunlight or in humid conditions, water ripple metal sheets maintain their beauty and functionality.

 

Versatility: The malleability of metal sheets allows designers to use them in various shapes and structures. Whether it's curved walls, roof coverings, or interior decorations, water ripple metal sheets can adapt effortlessly.

 

Environmentally Friendly: Many water ripple metal sheets are made from recyclable materials, making them an environmentally sustainable choice for construction. Compared to other materials, the production process of metal sheets generates less waste and allows for multiple cycles of reuse.

 

Applications of Water Ripple Metal Sheets

Building Facades: Water ripple metal sheets are commonly used for decorating building facades, giving them a unique appearance. Their rich texture and play of light and shadow provide different aesthetic experiences at different times and angles.

 

Interior Decoration: In interior design, water ripple metal sheets are often used for walls, ceilings, and partitions. With appropriate lighting and layout, they can create a comfortable, modern indoor environment.

 

Artworks and Sculptures: Designers and artists frequently use water ripple metal sheets to create artworks and sculptures. The material's unique texture lends vivid expression to the pieces, capturing the viewers' attention.

Water Ripple Metal Sheets 

Innovative Application Cases

Sustainable Architecture: Some innovative designs combine water ripple metal sheets with solar technology to form sustainable architectural solutions. These sheets not only serve decorative purposes but also capture solar energy and convert it into electricity.

 

Acoustic Regulation: Utilizing the properties of metal sheets, designers can develop walls and partitions with excellent acoustic effects. By adjusting the density and spacing of the sheets, sound propagation can be effectively controlled, improving the acoustic environment of the space.

 

Natural Ventilation Systems: Some buildings incorporate water ripple metal sheets in designing natural ventilation systems, utilizing the texture and gaps of the sheets to promote airflow, lower indoor temperatures, and enhance comfort.

 

In the design and architectural realm, water ripple metal sheets have become a highly sought-after material, with their unique aesthetic effects and multifunctionality shining in various applications. With technology and innovation continuously advancing, we can expect to see more awe-inspiring applications of water ripple metal sheets emerging.

Characteristics of spectral analysis

Atomic emission spectrum analysis has its unique advantages, especially suitable for pre-furnace analysis, so that it has become an essential analytical means for metal smelting and casting industry, and its characteristics are as follows:

(1) Multi-element simultaneous detection capability. Simultaneous determination of multiple elements in a sample. After each sample is excited, the different elements emit characteristic spectra, so that multiple elements can be determined simultaneously. For complex products, the more analytical elements are required to heal, and the economic benefits are good.

(2) Fast analysis speed. If the photoelectric direct reading spectrometer is used to analyze the sample without chemical treatment, the sample taken in the furnace can be excited on the sample table as long as the surface oxide is polished off, eliminating the trouble of drilling the sample for chemical analysis. For aluminum and copper, zinc and other non-ferrous metal samples, you can use a small lathe to remove the surface oxide can be directly measured. From sample excitation to the computer to report the element analysis content only 20-30 seconds, the speed is very fast, which is conducive to shortening the smelting time and reducing the cost. Especially for those elements that are easy to burn, it is easier to control their final composition.

 

(3) High accuracy. The analysis accuracy is very high, can effectively control the chemical composition of the product, ensure that it can meet the national standard specifications, and even the alloy composition can be controlled to the lower limit of the specification to save the consumption of intermediate alloys or ferroalloys.

(4) Less sample consumption.

(5) The analytical data can be printed out from the computer or stored on a floppy disk as a permanent record.

 

In short, from a technical point of view, photoelectric spectral analysis, it can be said that there is no more effective instrument than it can be used for rapid analysis in front of the furnace, with so many characteristics and can replace it. Therefore, the world's smelting, casting and other metal processing enterprises are competing to use this kind of instrument to become a conventional means of analysis, from the guarantee of product quality, from the economic benefits and other aspects, it is a very favorable analysis tool.

How to recover from demagnetization of NdFeB magnets?

     Demagnetization is the loss of magnetic field strength in magnets. Every magnet has a specific temperature, which is called the Curie temperature, at which it loses its magnetism. If magnets cool to room temperature, they may not regain previous super strong magnetic strength.

 

strong permanent magnetic materials

 

What causes strong neodymium magnets to demagnetize?

 

1. Influence of external magnetic field

     External magnetic fields, especially strong magnetic fields, can cause magnets to lose strength. The alignment of the magnetic domains can be disrupted when exposed to the north and south poles of another magnet.

 

2. Effects of heat exposure

     Heating permanent rare earth neodymium magnets to the Curie temperature causes its magnetic domains to randomize. Even if the magnet cools down, its original magnetic force may be reduced.

 

3. The role of working temperature

     Magnets' operating temperature is the highest temperature the magnets can withstand without significant loss of magnetic force. Neodymium magnets have a maximum operating temperature above which they may become demagnetized.

 

powerful neodymium round magnet

 

How to determine if neodymium magnets have been demagnetized?

 

     One must observe its magnetism and properties to determine whether strong power neodymium magnets have been demagnetized. Loss of strength or weakening of the magnetic field may be indicative signs. However, to understand the complete guide to demagnetization, one should understand the inherent properties of magnets such as permeability and temperature tolerance. Using tools or exposing a magnet to another magnet (such as an old magnet from the North) can provide further insight into its current state.

 

n52 block neodymium magnets

 

How to remagnetize a demagnetized neodymium magnet?

 

1.Make sure the demagnetized magnets are at room temperature.

 

2.Use stronger magnets or current to expose the demagnetized magnet to a strong magnetic field.

 

3.Make sure the magnets are aligned with the magnetization direction.

 

     PS:Make sure the magnets are only heated to its Curie point. Additionally, instruments are used to measure the strength that the magnet regains after remagnetization.

Different production processes of sintered and bonded neodymium magnets

     Ndfeb magnets can be divided into bonded NdFeb and sintered NdFeb. The difference between the two magnets is mainly in the production process: bonded neodymium magnet is injection molding by adding NdFeb magnetic powder to the adhesive; sintered neodymium magnet is vacuumed and molded by high temperature heating.

 

     1. Custom sintered neodymium magnet

 

custom sintered neodymium magnet

 

     In the process of sintering magnet manufacturing, neodymium magnet powder is mixed with appropriate additives and heated by high temperature sintering process. In the sintering process, the neodymium magnet powder particles will be combined to form a stable magnetic structure, thus forming a magnet with strong magnetism. Generally, through sintering, only blank can be produced, and then through mechanical processing (such as wire cutting, slicing, grinding, etc.) to become a magnet of various shapes. Sintered NdFeb is a hard and brittle material that is difficult to process, with large loss during processing. But the advantage is that sintered magnets usually have a high magnetic force and magnetic energy product, and have good temperature stability.

 

     Sintered Ndfeb is generally divided into axial magnetization and radial magnetization, and the magnetization direction can be customized according to the required work needs, while sintered Ndfeb has poor corrosion resistance and is easy to oxidize, so it is necessary to deposit on its surface, common nickel plating, galvanized, epoxy plating and so on.

     

     2. Custom bonded neodymium magnet

 

custom bonded neodymium magnet

 

     The bonded neodymium magnet is used adhesive to bond the neodymium magnet powder with other metal elements, so it is magnetic in all directions and resistant to corrosion. In the manufacturing process, neodymium magnet powder and adhesive are mixed to form a magnet by pressure or injection molding. Because it is molded by injection molding, the density is generally only 80% of the theoretical, and the magnetism is weaker than the sintered neodymium magnet. But the manufacturing method of bonded neodymium magnets allows for more complex shapes and structures, and can be used in combination with other materials.

 

     The above is the introduction of the difference between the production processing technology of bonded NdFeb and sintered NdFeb. Both types of custom neodynium permanent magnets have their advantages and application scenarios. Sintered magnet is commonly used in applications that require high magnetic force and temperature stability, such as engines, sensors, and nuclear magnetic resonance equipment. Bonded magnet is suitable for applications that require custom shapes and structures, such as magnetic pusher pins, magnetic labels, etc.

 

cuatomized different shapu ndfeb magnets

 

     In short, the manufacturing process of sintered magnet and bonding magnet is different, and the choice of the appropriate process depends on the specific application needs.

What Are Globe Valves Used For

Nowadays, most industries are using high-tech and modern types of valves to enhance production and operation.

Out of all the other types of industrial valves, globe valves are widely used in the oil, gas and fuel industries.

There are many uses of this type of valve as it works to stop as well as regulate the flow of liquids. If you want to know more about globe valves and their uses, follow this article.

What Are Globe Valves?

It is a type of linear motion valve which is used in different types of industries. It is designed in a way that you can use it for throttling as well. 

It has a spherical shape like a globe and comes with a disc. The disc moves in order to block as well as allow the flow of substances. When you close the valve, the disc entirely covers the pathway to stop the flow of fluids.

However, when you open the valve, the disc moves upwards in order to clear the pathway and allows substances to flow freely. It is mostly used for isolation and throttling purposes.

This type of industrial valves has good shutoff capability. You can use it to prevent leakages. Apart from that, it also offers good throttling capacity.

The stroke is shorter, which makes it easy to use and maintain. It is available in different types and designs. 

Applications and Uses of Globe Valves:

Globe valves have many applications. It is used for industrial as well as domestic purposes. The majority of the industries with plumbing needs use this type of valve. Here are some applications and uses of globe valves. 

Cooling Water Systems:

A globe valve helps maintain the heat and cooling of the system by regulating the flow. It helps in the adjustment of the temperature of the system in relation to the demand of heat or cool by taking the measurement of the changes in pressure. As a result, a valve regulates the amount of heat produced by the boiler. 

Fuel Oil Systems: 

A Globe Valve is a very important component of fuel oil systems. It helps to prevent and control the rate at which gasoline is burnt in an engine, thus enabling the engine to maintain a constant pressure of fuel at all times. It is usually found on the side of the engine near the firewall. It has a round-shaped body and has two cones on its side. 

Chemical Feed Systems:

A Globe valve is one of the important parts of chemical feed systems. It helps in the complete process of converting the feed mixture into a liquid, and it also helps in the separation of solids from the liquid mixture. A Globe valve has a piston, and it is rotatable. In this, the piston moves up and down due to the increase and decrease in pressure. 

Boiler, Main Stem Vents and Drains:

The globe valve is used in main steam and boiler rooms and drains as well. They can be used for controlling the amount of steam that enters a room from outside, regulate the water temperature in the boiler or condensate drain, or act as a thermostatic valve. It is commonly used in the hot water tank to prevent the loss of hot water from the tank through the pipes.

Turbine Lube Oil System:

A globe valve is used in a turbine lube oil system as it allows the flow of turbine oil to be limited to a single point. The oil is pumped by means of a turbine into a sump tank that is located above the turbine.

Product Inspection of Stainless Steel Reducers

Inspection of Stainless Steel Reducers
1. Geometry analyses of stainless steel reducers
The distribution trends of wall thickness of big and small concentric reducers are exactly the same. From the large end face to the section close to the small end face, the wall thickness changes from thin thickness to thick one. The inner hole of the small end has been turned after forming, and part of the wall thickness has been removed. However, the wall thickness of end faces of small ends is thinner than that of end faces of large ends, which is exactly the opposite of the eccentric reducer. This is caused by the manufacturing process. When the wall thickness of the axial section changes, there is obvious regularity for changes between the warp threads, but there is also a certain degree of dispersion.

2. Analyses of strength
The distribution trends of surface hardness of the large and small eccentric reducers are roughly the same, but they are not completely the same. The main difference is the hardness of the small end. The hardness of the small end of small eccentric reducers is higher, while the hardness of that of large eccentric reducers is lower. The tensile strength of the sample is 6.1% and 11% higher than the estimated strength value of the empirical formula. The yield strength and tensile strength of the sample 1 were increased by 9.0% and 2.0% respectively before production, and those of the sample 2 were increased by 26.4% and 8.8% compared with before production).

3. Conclusion
(1) The geometric dimensions of large and small ends of stainless steel reducers are more accurate, but the wall thickness is very uneven. As for stainless steel reducers with straight sections, the wall thickness of the small end of the eccentric reducer is thicker than that of the large end, while the wall thickness of the small end of the concentric reducer is thinner than that of the large end. The wall thickness of the reducing elbow is more uniform. Therefore, the geometric dimensions of the large and small ends must be measured when they are tested.
(2) The wall thicknesses of the stainless steel reducers tested are all extremely thick. It is recommended that a comprehensive wall thickness inspection record should be performed before they are used. With a basis for online thickness measurement to determine the thinning, the corrosion rate can be accurately reflected so as to ensure the safe operation of the pipeline.
(3) The ellipticity of the stainless steel reducer is less than 2%; the bending radius error of the reducing elbow is also small and can be ignored.
(4) The surface hardness of the two ends of the stainless steel reducer is about 35% lower than that of the middle section on average.
(5) After the final normalizing treatment, the yield strength and tensile strength of the stainless steel reducer made of large-diameter pipes by hot pressing are significantly improved.

Alloy Steel Pipes

Materials of alloy steel pipes 
Alloy steel pipes have good hardness, which are widely used for pipelines for transporting oil, natural gas, gas, water and certain solid materials. The common alloys are ferroalloys, ferro-chromium alloys, iron-nickel alloys, aluminum alloys(light weights) and copper alloys(good thermal conductivity). The main materials include 16-50Mn, 27SiMn, 20-40Cr, 12-42CrMo, 16Mn, 12Cr1MoV, T91, 27SiMn, 30CrMo, 15CrMo, 20G, Cr9Mo, 10CrMo910, etc. Alloy steel pipes made from 16Mn belong to low alloy steel pipes.
 
Applications of alloy steel pipes
Alloy steel pipes are mainly used for high-pressure and high temperature pipelines and equipment such as power plants, nuclear power, high-pressure boilers, high temperature superheaters and reheaters.
 
Three expressions of alloy steel pipe specifications
1. The first one is the outer diameter plus wall thickness. For example, an alloy steel pipe with an outer diameter of 57mm can be indicated by 57x3.
2. The second one is using the inner diameter, that is, the nominal inner diameter. For example, an alloy steel pipe with an outer diameter of 57mm is indicated by DN50.
3. The third one is the inch. For example, an alloy steel pipe with an outer diameter of 57mm can be indicated by 2 inches (1 inch equals to 25.4mm.)
 
Specific welding steps of alloy steel pipes
Welding processes of alloy steel pipes are heating before welding, quenching and tempering after welding.
 
Heating
Before welding the alloy steel pipe, it should be heated, and weld it after the temperature is controlled for 30 minutes. The heating and virtual beam temperature tempering of welding are actively operated by the temperature control cabinet for temperature adjustment. Adopt far infrared tracking heat treatment furnace plates. Intelligently and actively set the graph and record the graph, and use the thermal resistance to accurately measure the temperature. The thermal resistance measuring point is from 15mm to 20mm away from the edge of the weld during heating.
 
Welding methods
1. In order to prevent welding deformation of the alloy steel pipe, each column joint is welded symmetrically by two people, and the welding direction is from the middle to the two sides. After welding one to three layers, reverse planing should be carried out. After the carbon arc gouging is used, the welding equipment needs to be polished. The welding surface should be nitridation treated to show the metal texture and prevent the surface carbonization from causing cracks. The outer hole is welded once, and the remaining inner holes are welded once.
2. When welding alloy steel pipes with two layers, the welding direction should be opposite to that of the layer of alloy steel pipes. The butt welds of each layer are separated by 15 to 20mm.
3. The welding current, welding speed and number of overlapping layers of multiple welding machines should be maintained.
4. In welding, you must start welding from the pilot arc board and finish welding on the pilot arc board. Cut, polish and clean after welding.
 
Quenching and tempering after welding
After the seam are welded, it should be tempered within 12 hours. If the alloy steel pipe cannot be quenched and tempered immediately, heat preservation and slow cooling should be adopted. When the alloy steel pipe is tempered, temperatures of the two thermal resistances should be measured and the thermal resistance should be welded on both sides of the seam.

Technical requirements for steel pipes

This technical specification is suitable for the bidding for the procurement of steel pipe projects.

Executive standards

The steel pipe shall meet the following standards:

Quality standard like Spiral Welded Submerged Arc Welded Steel Pipes for Urban Heating CJ/T3022-1993 or Technical Delivery Conditions of Oil and Gas Industry Transportation Steel Pipes GB/T9711.1-2017 should be implemented for spiral welded pipes.

Seamless Steel Pipe for Fluid Transportation GB/T8163-2008 should be carried out as quality standards for seamless steel pipes.

Technical requirements for steel pipes

Materials

The steel pipe should be made of spiral seam welded steel pipes with Q235B.  The seamless steel pipe should adopt 20# steel.

Technical specifications

The quality and size of spiral seam welded steel pipes should conform to IS09330-1 or GB9711.1~2017 standards.

Spiral seam welded steel pipes should ensure that the minimum yield strength is greater than 235N/mm2.

Weld joints of steel pipes must meet the technical requirements of DIN1626 or GB3323-87.

Specifications, weights and errors of steel pipes

The supply of steel pipes shall comply with the relevant regulations in the latest GB9711.1-2017 or GB8163-2008.

The normal supply length of the steel pipe should be 12m with a length deviation of 0/+25mm.  When the length of the steel pipe is less than 12m due to the valve, compensator or pipeline turning, it should be supplied according to the actual length on site.

The thickness deviation requirements of the raw material steel plate of the steel pipe: when DN is 800mm, the negative thickness deviation should be smaller than or equal to 0mm.  When DN is greater than 800 and smaller than or equal to 1100mm, the thickness negative deviation should be less than or equal to 0mm.  When DN is greater than 1100 and smaller than or equal to 1200mm, the thickness negative deviation should be less than or equal to 3%.

The end of the steel pipe should be grooved.  The groove angle should be 30° and the deviation 0°/5°.  The size of the blunt edge should be 1.6±0.8mm.

The end surface of the steel pipe shall be perpendicular to the axis of the steel pipe.  When the nominal outer diameter is less than 508mm, the limit deviation shall not be greater than 1.5mm.  When the nominal outer diameter is greater than or equal to 508, the limit deviation shall not be greater than 2.0mm.

The ovality of the steel pipe end within 100mm shall not exceed ±1%D.

Requirements for manufacturers

In order to ensure the quality of the project, the following requirements are put forward for the materials and manufacturers of steel pipes and fittings:

The steel quality standards of steel pipes are equal to or higher than those of famous steel pipe manufacturers in China.

The quality standard of the steel pipe is equal to or higher than the product standard produced by the bidder, and the selected manufacturer must be approved by the tenderer and indicate in the bidding document.

At the same time, photocopies of the delivery quality certificate of the steel pipe raw materials, the quality certificate of the steel pipe, the special equipment manufacturing license (pressure pipe) that the manufacturer should have, and the inspection report issued by the local quality inspection department must be attached to the bidding documents.