Application fields of stamping robot

Application fields of stamping robot

It is an effective method to use stamping robot instead of manual operation to form a fully automatic production line in stamping production.

The overall design of the stamping robot should be considered comprehensively, so as to make it simple, compact, easy to operate, safe and reliable, convenient to install and maintain, and economical. The stamping robots used in industrial production have different structural types and different technical complexity due to different occasions and work requirements. To sum up, there are roughly the following aspects:

1. Automation with single machine: Many high-efficiency special processing equipment (such as various special machine tools, etc.) in production, if auxiliary operations such as loading and unloading of workpieces are continued by manual operation, not only will the labor intensity of workers increase, but also the efficiency of special equipment will not be fully exerted, which will inevitably affect the improvement of labor productivity. If stamping robot is used instead of manual loading and unloading, the above-mentioned unsuitable situation can be changed, the automatic production of single machine can be realized, and the conditions for multi-machine care can be provided. Such as automatic machine tools, automatic loading and unloading manipulators, stamping manipulators, injection molding machines and stamping robots, etc.

2. Forming automatic production line: On the basis of single machine automation, if stamping robots are used to automatically load, unload and transport workpieces, some single machines can be connected into an automatic production line. At present, stamping robots are widely used to realize automatic production in the production lines of shaft and disk workpieces. Such as: automatic production line for shaft machining and its automatic loading and unloading manipulator, automatic production line for machining and its manipulator, loading and unloading manipulator for NC machining machine tools, etc.

3. Automation of high-temperature operation: When working in high-temperature environment (such as heat treatment, casting and forging, etc.), the labor intensity of workers is high and the working conditions are poor, so it is more practical to use stamping robots to operate. Such as automotive leaf spring quenching manipulator, hydraulic press manipulator, etc.

4. Operating tools: Using stamping robot to hold tools and perform automatic operation under high temperature, dust and harmful gas environment can make people get rid of harsh working conditions, reduce labor intensity, improve labor productivity and ensure product quality.

5. Special operations: In modern science and technology, the application of atomic energy, the development of seabed resources, Ad Astra and so on have been familiar to people. However, radioactive radiation, or the seabed, the universe and other environments, are often inaccessible or inaccessible to the human body. Using remote-controlled stamping robots instead of people to carry out such operations can not only complete these special operations, but also work safely for a long time, thus becoming an effective means for human beings to March into new natural fields.

Practice has proved that industrial stamping robot can replace the heavy labor of human hands, significantly reduce the labor intensity of workers, improve working conditions, and improve labor productivity and production automation level. It is effective to use stamping robot for heavy workpiece handling and long-term, frequent and monotonous operation in industrial production. In addition, it can operate under high temperature, low temperature, deep water, cosmic, radioactive and other toxic and polluting environmental conditions, which shows its superiority and has broad development prospects.

Decho is a professional supplier on  stamping robot and stamping automation , if you have any request , pls donot hesitate to contact us by email [email protected]

Nondestructive testing of welded pipe fittings: NDT

Nondestructive testing of welded pipe fittings: NDT

Definition of NDT for welded pipe fittings: NDT refers to a testing method for materials or workpieces that does not damage or affect their future performance or use.

NDT can find defects in the interior and surface of materials or workpieces, measure the geometric features and dimensions of workpieces, and determine the internal composition, structure, physical properties and state of materials or workpieces.

NDT can be applied to product design, material selection, processing and manufacturing, finished product inspection, in-service inspection (maintenance), etc. It can play an optimal role between quality control and cost reduction. NDT also helps to ensure the safe operation and/or effective use of products.

Types of nondestructive testing methods NDT contains many effective methods.

According to the physical principle or different detection objects and purposes, NDT can be roughly divided into the following methods:

A) radiation method: -(x-ray and gamma-ray radiographic testing); -Radiographic testing; -Computed tomographic testing; —— neutron radiographic testing.

B) acoustic method: -ultrasonic testing; -acoustic emission testing; -electromagnetic acoustic testing.

C) electromagnetic method: -eddy current testing; -flux leakage testing.

D) surface method: -magnetic particle testing; -(liquid) penetrant testing; -visual testing.

E) leakage method: -leak testing.

F) infrared method: -infrared thermal imaging testing.

Conventional NDT methods are widely used and mature NDT methods at present, which are: radiographic testing (RT), ultrasonic testing (UT), eddy current testing (ET), magnetic particle testing (MT) and penetrant testing (PT).

Some NDT methods will produce or incidentally produce substances such as radioactive radiation, electromagnetic radiation, ultraviolet radiation, toxic materials, flammable or volatile materials, dust, etc., which will harm human body to varying degrees. Therefore, when applying NDT, necessary protection and monitoring should be carried out according to the types of harmful substances that may be produced, and necessary labor protection measures should be taken for relevant NDT personnel.

Each NDT method has its own capabilities and limitations, and the detection probability of defects by each method is neither 100% nor completely the same. For example, radiographic testing and ultrasonic testing, the testing results of the same object are not completely consistent.

In the conventional NDT method, radiographic testing and ultrasonic testing are mainly used to detect the defects inside the tested object; Eddy current testing and magnetic particle testing are used to detect defects on the surface and near surface of the tested object; Penetration testing is only used to detect the defects of the surface opening of the tested object.

Radiographic inspection is suitable for detecting volumetric defects in the inspected object, such as porosity, slag inclusion, shrinkage cavity, porosity, etc. Ultrasonic testing is suitable for detecting area defects in the tested object, such as cracks, white spots, delamination and incomplete fusion in welds.

Radiographic inspection is often used to inspect metal castings and welds, and ultrasonic inspection is often used to inspect metal forgings, profiles and welds. Ultrasonic inspection is usually superior to radiographic inspection in detecting defects in welds.

Radiographic inspection (RT)

Scope of competence:

A) defects such as incomplete penetration, porosity and slag inclusion in the weld can be detected;

B) defects such as shrinkage cavity, slag inclusion, porosity, looseness and hot cracking in castings can be detected;

C) can determine the plane projection position and size of the detected defects, as well as the types of defects.

Note: The transillumination thickness of radiographic inspection is mainly determined by ray energy. For steel materials, the transmission thickness of 400 kV X-ray can reach about 85 mm, cobalt 60 gamma ray can reach about 200 mm, and the transmission thickness of 9 MeV high-energy X-ray can reach about 400 mm..


A) it is difficult to detect the defects in forgings and profiles;

B) it is difficult to detect the fine cracks and incomplete fusion in the weld.

Ultrasonic testing (UT)

Scope of competence:

A) defects such as cracks, white spots, delamination, large or dense slag inclusion in forgings can be detected;

Note 1: Internal defects or defects parallel to the surface can be detected by direct technology. For steel materials, the maximum effective detection depth can reach about 1 m;

Note 2: Non-parallel defects or surface defects can be detected by oblique or surface wave technology.

B) It can detect defects such as cracks, incomplete penetration, incomplete fusion, slag inclusion, porosity, etc. existing in the weld;

Note: Oblique shooting technique is usually used. If 2.5 MHz ultrasonic wave is used to detect steel weld, the maximum effective detection depth is about 200 mm

C) defects such as cracks, folds, delamination and flaky slag inclusion in profiles (including plates, pipes, bars and other profiles) can be detected;

Note: Generally, liquid immersion technology is used, and focusing oblique shooting technology can also be used for pipes or bars.

D) It can detect the defects such as hot crack, cold crack, looseness, slag inclusion, shrinkage cavity, etc. in castings (such as steel castings with simple shape, flat surface or machined and repaired ductile iron);

E) the coordinate position and relative size of the detected defects can be determined, but it is difficult to determine the types of defects.


A) it is difficult to detect defects in coarse-grained materials (such as castings and welds of austenitic steel); B) It is difficult to detect defects in workpieces with complex shapes or rough surfaces.

Eddy current testing (ET)

Scope of competence:

A) it can detect defects such as cracks, folds, pits, inclusions and porosity on the surface and/or near the surface of conductive materials (including ferromagnetic and non-ferromagnetic metal materials, graphite, etc.);

B) The coordinate position and relative size of the detected defects can be determined, but it is difficult to determine the types of defects.


A) not applicable to non-conductive materials;

B) the internal defects existing in the far surface of the conductive material cannot be detected;

C) it is difficult to detect the defects on or near the surface of a workpiece with complex shape.

Magnetic particle inspection (MT)

Scope of competence:

A) it can detect the defects such as cracks, folds, interlayers, inclusions and air holes on the surface and/or near the surface of ferromagnetic materials (including forgings, castings, welds, profiles and other workpieces);

B) It can determine the position, size and shape of the detected defect on the surface of the inspected object, but it is difficult to determine the depth of the defect.


A) it is not suitable for non-ferromagnetic materials, such as austenitic steel, copper, aluminum and other materials;

B) internal defects existing in the far surface of ferromagnetic materials cannot be detected.

Penetration testing (PT)

Scope of competence:

A) defects such as open cracks, folds, looseness, pinholes and the like on the surfaces of metal materials and dense nonmetal materials can be detected;

B) It can determine the position, size and shape of the detected defect on the surface of the inspected object, but it is difficult to determine the depth of the defect.


A) it is not suitable for loose porous materials;

B) defects existing in the material interior and/or near the surface without opening can not be detected

Decho is a professional supplier on  pipe fittings , if you have any request , pls donot hesitate to contact us by email [email protected]

Tube bending production process

Tube bending production process

 At present, there are basically two kinds of pipe bending production processes in China:

The first type: small-diameter pipeline, the general outer diameter specification is ≤89mm, and cold bending is usually adopted, which is carried out by manual or numerical control pipe bending machine. After bending, annealing heat treatment is needed to eliminate the deformation stress inside the bent pipe.

Type 2: large diameter and high pressure pipelines usually have an outer diameter of ≥114mm and are usually hot bent. Medium-frequency heating is used to heat the pipeline, and mechanical or hydraulic mechanism is used to apply external force to bend the pipeline.

Comparison of two processes:

Cold bending does not change the organizational structure of steel pipe, and keeps the original mechanical properties of steel pipe well, but because of its great deformation resistance, it is not suitable for bending of large diameter and thick wall pipeline; At the same time, cold bending will produce great stress concentration, so it is necessary to anneal the pipeline.

Hot bending needs to heat the pipeline, which has certain influence on the mechanical properties and service life of the pipeline itself. Usually, in order to better ensure the service performance of elbow, the elbow should be heat treated after hot bending if necessary.

Decho is a professional supplier on bending pipes , if you have any request , pls donot hesitate to contact us by email [email protected]

How are qualified pipe fittings produced?

How are qualified pipe fittings produced?

If the finished pipe fittings are viewed from the outside, it is difficult to distinguish between good and bad quality, which is only known during the use process. Engineering quality pays attention to safety first, and once an accident happens, it will cause irreparable losses.

So how are high-quality and qualified pipe fittings produced? Mainly consider the following links:

1. The raw materials of pipe fittings are base materials: in order to manufacture qualified pipe fittings, qualified raw materials must be selected. That is to say, the steel pipes, steel plates and billets used for manufacturing pipe fittings must be products that meet the requirements of the corresponding national standards after inspection. In practice, in order to reduce production costs, bad manufacturers use pipes or other raw materials from unknown sources, some purchase engineering surplus materials, some purchase defective pipes and test machine products processed by steel mills, some purchase retired oil and gas transmission steel pipes that have expired, and some use low-grade steel instead of high-demand steel, such as seamless steel pipes of GB/T 8162 instead of seamless steel pipes of GB/T8163, and even welded steel pipes with treated welds instead of seamless steel pipes. All these have brought endless hidden dangers to the purchaser.

2. Die for producing pipe fittings: The pressing, extruding and forging of dies are indispensable in the forming process of pipe fittings, so factories are required to inspect various manufacturing dies frequently to minimize the defects such as strain and scratch in the forming process of pipe fittings.

3. Heat treatment of pipe fittings: The main functions of heat treatment are to relieve stress, reduce hardness, refine grains and improve structure and performance. For stainless steel, it means austenitizing. Especially cold-formed pipe fittings, all must be heat treated. However, small coal furnaces are still used for heat treatment in very small factories, and the work depends entirely on workers’ experience, and the furnace temperature is unstable and uneven, which cannot guarantee the heat treatment effect. 4. NDE for pipe fittings: National and international standards have corresponding provisions on NDE for formed pipe fittings. For example, the cold extruded tee must be 100% magnetic particle inspected, and the weld must be 100% radiographic inspected. However, because some factories do not have the testing power, are lucky or overconfident, they omit the essential nondestructive testing link, and do not find the major surface or internal defects of the products, which foreshadows the hidden dangers.

5. Preparation of pipe ends: Most pipe fittings will be welded with pipes or other pipe fittings at the project site. This requires that the roundness, thickness and groove of the pipe end must be excellent, otherwise it will bring difficulties to the welding in the project site, and then affect the welding quality of the project. Some people think that the wall thickness of our pipe fittings is not worse than that required by customers, so there should be no problem. As everyone knows, too thick end thickness will also make welding impossible on site.

Decho is a professional supplier on pipe fittings , if you have any request , pls donot hesitate to contact us by email [email protected]

Principle and classification of check valves

Principle and classification of check valves


Check valve The function of this type of valve is to allow the medium to flow in one direction only, and to prevent the opposite direction. Usually, this kind of valve works automatically, and the valve flap opens under the pressure of fluid flowing in one direction; When the fluid flows in the opposite direction, the fluid pressure and the self-overlapping disc of the disc act on the valve seat, thus cutting off the flow.

Structural classification

According to the structure, it can be divided into three types: lift check valve, swing check valve and butterfly check valve:

1. Lift check valves are divided into vertical and horizontal types.

2. Swing check valves are divided into three types: single-flap, double-flap and multi-flap.

3. Butterfly check valve is straight-through.

The above check valves can be divided into four types in connection form: threaded connection, flange connection, welding connection and butt clamp connection.

Material classification

1. Cast iron check valve

2. Brass check valve

3. Stainless steel check valve

4. Carbon steel check valve

5. Forged steel

check valve functional classification

1.DRVZ silent check valve Stainless steel check valve Stainless steel check valve

2.DRVG silent check valve

3.NRVR silent check valve

4.SFCV rubber flap check valve

5.DDCV double disc check valve


Decho is a professional supplier on check valves, if you have any request , pls donot hesitate to contact us by email [email protected]

What should we pay attention to when using three screw pump?

What should we pay attention to when using three screw pump?


1. Selection of speed of three screw pump The flow rate of three screw pump has a linear relationship with rotation speed. Compared with the low-speed screw pump, the high-speed screw pump can increase the flow rate and lift, but the power is obviously increased. The high-speed screw pump accelerates the wear between rotor and stator, which will definitely lead to premature failure of the screw pump. Moreover, the stator and rotor of the high-speed screw pump are short in length and easy to wear, thus shortening the service life of the screw pump. The speed can be reduced by speed reducer or stepless speed regulation mechanism, so that the survey speed can be kept within a reasonable range below 300 revolutions per minute. Compared with the screw pump running at high speed, the service life can be prolonged several times.

2. The quality of screw pump There are many types of screw pumps in the market. Relatively speaking, the imported screw pumps are reasonable in design and excellent in material, but the price is high, some services are not in place, the price of accessories is high, and the ordering cycle is long, which may affect the normal operation of production. Most of the domestically produced products are imitations of imported products, and the quality of the products is mixed. When selecting domestically produced products and considering their cost performance, products with low speed, long lead, excellent transmission parts and long rated life are selected.

3. Ensure that sundries do not enter the pump body Solid impurities mixed in wet sludge will damage the rubber stator of screw pump, so it is very important to ensure that impurities do not enter the pump cavity. Many sewage plants have installed pulverizers in front of pumps, and some have installed grille devices or filters to prevent impurities from entering the screw pump. The grille should be cleaned in time to avoid blockage.

4. Maintain a constant outlet pressure Screw pump is a kind of positive displacement rotary pump. When the outlet end is blocked, the pressure will gradually increase to exceed the predetermined pressure value. At this time, the load of motor will increase sharply. The load of related parts of transmission machinery will also exceed the design value. In severe cases, the motor will burn out and the transmission parts will break. In order to avoid the damage of screw pump, a bypass overflow valve is usually installed at the outlet of three screw pump to stabilize the outlet pressure and keep the normal operation of the pump.

5. Avoid cutting materials Three screw pump will never be allowed to run under the condition of material breakage. Once it happens, the rubber stator will burn out due to the instantaneous high temperature caused by dry friction. Therefore, the crusher is in good condition and the grille is unblocked, which is one of the necessary conditions for the normal operation of screw pumps. For this reason, some screw pumps are also equipped with material breakage shutdown devices. When material breakage occurs, vacuum will be generated in the cavity due to its self-priming function, and the vacuum device will stop the screw pumps from running.

Decho is a professional supplier on screw pumps , if you have any request , pls donot hesitate to contact us by email [email protected] .

Horizontal stainless steel storage tank

Characteristics of stainless steel storage tanks:

1. Stainless steel tank has strong corrosion resistance, which is not corroded by residual chlorine in outside air and water. Each spherical tank is subjected to strong pressure test and inspection before leaving the factory, and its service life can reach more than 100 years under normal pressure.

2. The stainless steel tank has good sealing performance; Sealed design _ prevents harmful substances and mosquitoes from invading the tank, and ensures that the water quality is not polluted by the outside world and breeds red worms.

3. The scientific water flow design makes the sediment at the bottom of the tank not turn up because of the water flow. _ Domestic water and fire water are naturally layered, and the turbidity of domestic water coming out of the tank is reduced by 48.5%; But the water pressure increased obviously. It is beneficial to improve the performance of domestic water and fire water facilities.

4. Stainless steel tanks do not need to be cleaned frequently; Precipitated substances in water can be discharged only by regularly opening the drain valve at the bottom of the tank. Scale can be simply prepared once every three years, which greatly reduces the cleaning cost and avoids human bacterial and viral pollution.

Application of stainless steel storage tank:

Stainless steel storage tanks are tanks made of stainless steel. Compared with ordinary rotomoulded storage tanks, stainless steel storage tanks can withstand high pressure and are widely used in many high-pressure occasions.

At the same time, stainless steel storage tanks have a remarkable feature: The tank has excellent sealing performance, which eliminates the invasion of harmful substances and mosquitoes in the air, and ensures that the liquid stored in the tank will not be polluted by the outside world and will not breed red worms. Therefore, stainless steel storage tanks are mostly used for storing and transporting food and medicines, and are widely used in brewing industry and dairy industry.


Decho is a professional supplier on storage tanks, if you have any request , pls donot hesitate to contact us by email [email protected]

What should we pay attention to in the application of wafer butterfly valve?

Wafer butterfly valve is a widely used valve. According to valve materials and driving forms, wafer butterfly valve can adapt to many different industries.

Sealing materials for wafer butterfly valves can be roughly divided into two types: soft sealing type and hard sealing type. Soft seal butterfly valve has excellent performance, but it can not be used in high temperature and high pressure pipeline due to the limitation of sealing materials. The sealing material of hard sealing butterfly valve is metal, which can resist high temperature and pressure, but its sealing performance is not particularly good.

Introduction of main parts and materials of wafer butterfly valve:

1.Valve body: gray cast iron, nodular cast iron, cast steel, stainless steel, etc.

2.Butterfly plate: nodular cast iron, cast steel, stainless steel, etc.

3.Valve stem: usually stainless steel;

4.Seat: soft seal (EPDM, NBR, PTFE, etc. ), hard seal (cemented carbide).

The driving forms of wafer butterfly valves are: handle drive, turbine drive, pneumatic drive, electric drive and so on.

Compared with valves with other connection forms, wafer butterfly valves have shorter structure length and smaller size, and are suitable for installation in narrow space environment. So what should we pay attention to when installing wafer butterfly valve?

  1. Before installation, clean the sealing surface of the valve and the inside of the pipeline without dust and impurities.
  2. The wafer butterfly valve needs a special flange. During installation, the flange hole position must be aligned with the “ear” hole position of the valve, and the flange part and the valve sealing ring are tightly pressed together.
  3. After the valve is fixed in the pipeline, it is necessary to do several valve opening and closing tests to observe whether there is blockage during the opening and closing of the butterfly plate.
  4. When installing the electric or pneumatic actuator of butterfly valve, attention should be paid to the position of actuator and butterfly plate, which should be assembled from opening to closing, and installed on the pipeline after assembly and debugging.

Decho is a professional supplier of butterfly valves, if you need any for your project, pls contact us by e-mail [email protected]

Bearings prolong service life-sealing effect

Bearings are the basis for operating machinery, covering fields ranging from mining, motors, machine tools to transportation, power generation, and robotics. Ensuring the longest possible service life is essential to prevent excessive wear and tear; this wear and tear can lead to system failures, often leading to expensive downtime for equipment rebuilds.

Engineers can use standard bearing life expectancy to calculate the likely life of the bearing supply. Known as L10 life (or also known as B90 or C90 life), this theorem explains that 90% of bearings will reach or exceed a specific number of revolutions when used in a specific working environment. However, this expectation is not guaranteed; in practical applications, bearing failures are actually more common and more complex, affecting the life expectancy of most systems.

Although many factors can maximize the life of a bearing, the most important consideration is proper sealing-recent studies have shown that most bearing failures are caused by contaminated bearing oil. By using the best quality seals, engineers can prevent or greatly reduce pollution, significantly extend bearing life, while improving equipment uptime and preventing system failures.

Two main sealing systems

In order to protect the bearing, the seal helps to reduce excessive temperatures by effectively retaining the lubricant, thereby reducing wear. Perhaps more importantly, the seal prevents foreign debris from entering the bearing, preventing damage, deteriorating bearing performance, and ultimately causing them to stop working altogether.

The two most common sealing arrangements are called radial lip or friction contact seals, and labyrinth or non-contact seals. Both sealing systems help protect the bearing and extend the service life. Depending on the application, different designs are different, which ultimately determines the level of protection provided by these seals.

Friction contact seal

Early friction contact seals were made to maintain consistent contact with the sealing surface; today’s models use special shapes and geometries to create hydrodynamic effects, and more effective designs to maintain maximum protection. This design enables the seal to reduce friction and wear by circulating lubricating oil from under the sealing lip to the bearing system, thereby forming an advanced process that improves life and efficiency.

There are many friction seal designs that provide excellent performance at a slightly higher cost, such as a surface seal with a spring element, which can provide automatic adjustment, or a seal with two collars, with a grease collector around it, which can automatically Add grease. In addition to these options, the next best cost-effective option includes regular or occasional lubrication and a collar that is updated from the bearing. The cheapest options include collars that are not updated, felt rings that are occasionally updated, and felt rings that are never updated.

Non-friction seal

Non-contact sealing continues to be popular. The most common type is the labyrinth seal, which is designed with complex passages to prevent contaminants from entering while retaining lubricant and liquid. Another option is a hybrid design, which includes centrifugal force, drainage design, and other retention and removal methods to provide the best sealing performance.

The most effective (and most expensive) labyrinth seal arrangement includes a multi-channel model with automatic or regular grease replenishment. The multi-channel labyrinth seal where the bearing is occasionally re-lubricated is the second best choice, followed by the simple-running Nilos ring and the long-gap seal. More economical models with a shorter service life include short gaps, Z shields, and open bearing non-contact seals.

Decho is a professional supplier of bearings. If you need any type, pls contact us by email [email protected]

E-type bearings: toughness and economy

Bearings are used in almost every industry, but sometimes designers need rugged parts that work reliably in the harshest environments. E-type bearings are very suitable for these conditions and can roll smoothly even in the presence of debris, dirt, water, chemicals and high temperatures.

Another key benefit is that the rolling elements are tapered roller bearings, which can accommodate high radial and thrust loads.

In Decho, needle roller bearings have become our best-selling products because of their cost-effective design. The key lies in the housing: these components use strong steel, cast iron or other strong materials to protect the bearing and provide excellent performance throughout the life of the bearing.

Two main types of units

There are two main designs of E-type bearings: standard and split. The standard unit has a single, solid shaft-ready housing, while the separate unit consists of two separate housings, providing greater flexibility in difficult settings.

Standard E-mounting units-robust material construction makes these units the best choice for high-capacity applications, with special bearings that can adapt to temperatures up to 350°F.

All standard E-type bearings are pre-lubricated and fully assembled to withstand radial, thrust and impact loads. Advanced applications and industries such as mining, water treatment, mills and paper shredders require such powerful bearings.

Split housing E-type mounting units-the split structure of these units allows them to accommodate deviations of up to ±4°. It can be used for the expansion design of the super long linear axis to ensure the largest positive contact and excellent performance.

The split housing unit reduces downtime by inserting replacement parts, allowing quick and convenient maintenance, while keeping the housing base fixed and aligned. Can be used for steel, split housing units in the toughest industries where booming applications, such as forestry, marine, fans and blowers, and cement.

Decho is a professional supplier on needle bearings, if you need any , pls contact us by email [email protected]