Surface Finish Measuring for iron casting plate

Machining Surface Finish Chart

Machining Surface Finish Chart

Machining surface finish

Machining surface finish is also called surface roughness. It refers to the small spacing and the unevenness of small peaks and valleys of the processed surface. The distance between its two crests or troughs is very small (below 1mm), which is a microscopic geometric shape error. The smaller the surface roughness, the smoother the surface.

Surface roughness is generally formed by the processing method used. At the same time, there are also other factors. For example, the friction between the tool and the surface of the part during the processing, the plastic deformation of the surface layer metal when the chips are separated, and the high-frequency vibration in the process system. Due to the difference in processing methods and workpiece materials, the depth, density, shape and texture of the traces left on the processed surface are different.

Surface roughness is closely related to the matching properties, wear resistance, fatigue strength, contact stiffness, vibration and noise of mechanical parts. And it has an important impact on the service life and reliability of mechanical products. According to international standards, we use Ra for labeling.

Measurement methods

1. Comparative method

The comparative method is simple to measure, and for on-site measurement in the workshop. This method is suitable for measurement on medium or rough surfaces. In brief, the method is to compare the measured surface with a roughness model marked with a certain value to determine the value. The methods that can be used for comparison is as follows. 1. Use visual inspection when Ra>1.6μm. 2. Use a magnifying glass when Ra1.6~Ra0.4μm. 3. Use a comparison microscope when Ra<0.4μm.

When comparing, the processing method, texture, direction, and material of the sample should be the same as the surface of the tested part.

2. Stylus method

Use a diamond stylus with a tip curvature radius of about 2 microns to slowly slide along the measured surface. The up and down displacement of the diamond stylus is converted into an electrical signal by an electrical length sensor. After amplification, filtering, and calculation, the display instrument indicates the rough surface degree value. We can also use the recorder to record the profile curve of the measured section.

Generally, the measuring tool that can only display the surface roughness value is called the surface roughness measuring instrument. And the surface roughness profiler that can record the surface profile curve at the same time. These two measurement tools have electronic calculation circuits or electronic computers, which can automatically calculate the arithmetic mean deviation Ra of the contour, the ten-point height of the microscopic unevenness Rz, the maximum height of the contour Ry and other various evaluation parameters. The measurement efficiency is enough high and is suitable for measuring the surface roughness with Ra of 0.025~6.3 microns.

Surface Finish Measuring for iron casting plate

Surface Finish Measuring for iron casting plate

3. Light section

The double-tube microscope measures the surface roughness, which can be used to evaluate Ry and Rz parameters, and the measurement range is 0.5-50.

4. Interference method

Use the principle of light wave interference (see flat crystal, laser length measurement technology) to display the shape error of the measured surface as interference fringe patterns. Meanwhile, use a microscope with high magnification (up to 500 times) to enlarge the microscopic part of these interference fringes Perform measurement to obtain the measured surface roughness. The surface roughness measurement tool using this method is interference microscope. In addition, this method is suitable for measuring surface roughness with Rz and Ry of 0.025 to 0.8 microns.

 

If you need to know more about related knowledges, please pay attention to our website.

Yide casting is a leading casting foundry in China, with 27 years’ experience, produces top quantity ductile iron castings. If you are interested in our casting fitting, please send us a drawing file, and feel free to get a quite quote.

Detection Methods and Difficulties of Steel Castings

Detection Methods and Difficulties of Steel Castings

Difficulties in detection

1. Poor ultrasound penetration

Coarse grains, uneven structure and other complex interfaces enhance the scattering of ultrasonic waves. And the energy attenuation is large, so that the detectable thickness is smaller than that of forgings.

2. Many interference clutter

When the sound wave is scattered on the uneven, non-dense structure and coarse grain interface, the intensity of the scattered signal is larger and is received by the probe. The rough casting surface will form clutter on the sound wave reflection. These will display on the oscilloscope screen as a messy forest-like echo (also called grass-like echo), which may flood the defect echo and hinder the identification of the defect echo.

3. Poor surface coupling conditions

The surface of the steel casting is rough, which is not conducive to the coupling of sound. At the same time, the surface hardness is large and difficult to polish.

4. Difficult to quantify defects

Due to the large attenuation of sound waves by steel castings and the complicated shape of defects, the quantitative evaluation of defects based on artificial defects has large errors. As a result, it is more difficult to quantify defects by calculation.

The above is exactly the difficulty of casting inspection. These difficulties make casting inspection subject to certain restrictions. But on the other hand, due to the lower quality requirements of castings, single defects are allowed. Meanwhile, the parts where casting defects appear are regular. Therefore, casting detection still has a certain value. 

 

 

  • Detection methods

1. Small and medium size castings

For small and medium-sized castings (especially investment precision castings), which are small in size, light in weight, and less processed, they can be magnetized in at least two substantially perpendicular directions on a stationary magnetic particle inspection machine. It is best to use direct current or pulsating direct current, and use the wet continuous method for inspection. Direct energization method, rod-through method, flux method and coil method are all available.

2. Large and heavy castings

For larger and heavier castings, magnetize parts or zones in at least two substantially perpendicular directions. It is best to use a portable or mobile magnetic particle flaw detector with DC or half-wave rectification. And use the contact or yoke method, dry or wet continuous method to detect parts or zones of castings. Testing should generally be carried out in two mutually perpendicular directions.

3. Take the following measures to prevent burning of the castings in contact with the electrodes

when the contacts are not completely in contact with the surface of the castings, no current is connected; and remove the contacts only when the current has been disconnected. In addition, use sufficiently clean and suitable contacts. For smooth and clean surfaces that have been machined, use yoke method.

4. Due to the influence of casting stress, some cracks (cold cracks) of steel castings will delay cracking. Therefore, we should not carry out test immediately after casting, but after 1 to 2 days.

5. If the casting is rejected due to the defect exceeding the acceptance criteria, and digging (shoveling) and repair welding are allowed, the repair welding area should also pay attention to control the delayed cracks.

6. The inspection should be done with the naked eye. And magnifying glass less than 3 times can be used only in the inspection of 001 and 01 quality levels.

 

Yide casting is a leading casting foundry in China, with 27 years’ experience, produces top quantity steel castings. If you are interested in our casting fitting, please send us a drawing file, and feel free to get a quick quote.

lead acid battery pallet jack

The Development History of Logistics Pallet Trucks

The pallet truck is the logistics handling equipment that transport goods. The development history of pallet trucks has experienced three generations, and is developing to the fourth generation.

1. Manual Pallet Jacks

The first-generation pallet truck is a manual pallet truck. It is characterized by a low degree of automation and intelligence. However it has made a huge contribution to the conversion of manual handling to mechanized handling. Today, it is still in the pallet truck market, and take a certain market share.

 

 

2. Internal Combustion Pallet Trucks

The second-generation pallet truck is the internal combustion pallet truck. The 2nd generation is represented by the internal combustion forklift, which has high automation. The internal combustion forklift is powered by the engine and has strong power. The disadvantage is that the exhaust emission pollutes the environment, and the efficiency is low. Besides, it is harmful to human health. Thus it is not suitable for use in the food industry.

3. Electric Pallet Trucks

The third-generation pallet truck is all-electric pallet truck. Its degree of automation is equivalent to that of internal combustion pallet truck. However the electric pallet jack is a power technology update based on the concept of energy saving and environmental protection. It uses battery power and has the advantages of energy saving, no exhaust gas emissions, and low noise. It is the best choice for food industry. Due to its outstanding advantages of energy saving, it is considered by the truck industry as one of the most potential handling equipment in the future.

 

4. Automated Guided Vehicles System

The development of the fourth-generation transport vehicle is represented by automated guided vehicles system, referred to as AGVS. AGVS is expected to be widely used in the 1950s. It is an effective means of logistics transportation in today’s flexible manufacturing system (FMS) and automated warehouse system.

Modern AGVs are controlled by computers. Most AGVS is equipped with a centralized control and management computer for the system. The system is used to optimize the operation process of the AGV and issue handling instructions. At the same time, it can also track the components in transmission and control the route of the AGV. The guidance methods of unmanned vehicles mainly include electromagnetic induction guidance, laser guidance and magnet gyro guidance. We can input program to guide the vehicle to complete the handling work. AGVS is a kind of truck with higher intelligence.

Daily Maintenance of 5 Key Parts of Manual Hydraulic Pallet Truck

The manual pallet truck is undoubtedly a common handbarrow in modern logistics, which is found in factories of all sizes. It is also widely used in various industries such as postal services, airports, warehouses, workshops and supermarkets. In a modern society, the handling of materials is inseparable from manual pallet trucks. Thus the truck is also called “the king of land”.

In the process of social development and changes, the demand for manual pallet trucks is also undergoing new changes, and the number of companies with personalized needs is gradually increasing. Various types of trucks appear in the market, in order to meet market demand, such as: widened manual trucks, large-tonnage manual trucks, scissor manual trucks, electronic scale trucks, electric trucks, etc.

However, all types of manual pallet trucks are faced with a problem. That is, the after-sales service and maintenance of manual pallet trucks. As the saying goes: there is nothing in the world that is not bad. No matter how good the product is, there are times when it is damaged or eliminated. Therefore, solving the after-sales service maintenance problem is the guarantee for the continuous operation of the manual pallet truck.

Today, Yide Casting will give you an analysis of the 5 key parts that are prone to having problems. And above all, how to solve these problems.

iron casting oil pump

1. Oil pump

The oil pump is a key part of all trucks. Once there is a problem with the oil pump, it means that the truck is declared to stop working. Even though the other parts are good and without any damage. The oil pump consists of a lot of parts. Among them, dust-proof rings, O-rings, steel balls and other parts are prone to having problems. Once problems with these parts are found, the quicker solution is to replace these accessories.

hand pallet truck cylinder
2. Oil cylinder

The oil cylinder plays a vital role in the entire lifting process of the truck. And it is also used to rise and fall the goods. Therefore, if the fork cannot be lowered or raised, the reasons are: 1. The piston rod and the oil cylinder may be damaged due to overload or partial load during the load; 2. The piston rod is exposed for a long time and rusts, thus hinder the smooth movement of the piston; 3. The adjusted nut and hex nut are not in the correct position. At this time, we should replace the piston rod or cylinder, lower the truck to the lowest level when the truck is not used, and readjust the nut.

3. Oil seal

The oil seal is the key component between the piston rod of the oil cylinder and the cylinder barrel. Imported sealing rings are generally used. Mainly because of good sealing performance, wear resistance and long service time. And 70% of the oil leakage of the oil cylinder occurs on the oil seal. If oil leakage is found in the oil cylinder, check it in time. If the sealing ring is aging or damaged, replace it with a high-quality one.

4. Wheels

Handling wheels will wear out if they are used for a long time. There are also many kinds of wheels for handling vehicles, such as nylon wheels, PU wheels, polyurethane coated nylon, rubber wheels, bakelite, etc. Most trucks are equipped with nylon wheels because they are common in the market and cheap, but they are less worn and noisy when walking. Please replace the transport wheels in time if they are worn to a certain extent.

5. Lever frame

The lever frame is the key component connecting the oil pump and the push rod. The lifting support of the hydraulic cylinder and the carrying and loading of goods are supported by the lever frame to achieve a balance. Because of the possibility of overloading and unbalanced loading when handling goods, which often lead to deformation or fracture of the lever frame. Once this happens, the truck cannot operate normally. At this time, you contact the manufacturer or purchase a replacement lever frame.

10 Principles to Reduce Casting Defects

In the production process, foundry enterprises inevitably encounter casting defects such as shrinkage, bubbles, segregation, etc. This will result in low casting yield, and re-reflow production faces a lot of manpower and power consumption. How to reduce casting defects is a problem that has always been concerned by casting professionals.

For the problem of reducing casting defects, John Campbell, a professor from the University of Birmingham in the United Kingdom,  have experienced many battles and has unique insights on reducing casting defects. As early as 2001, Li Dianzhong, a researcher at the Institute of Metal Research of the Chinese Academy of Sciences, carried out the organization simulation and process design of the thermal processing process, which was completed under the guidance of Professor John Campbell.

Hope the list of ten guidelines for reducing casting defects by international foundry master John Campbell is helpful to colleagues in the foundry industry.

1. Good castings start from high-quality smelting

We must prepare, inspect and process the smelting process before pouring the castings. If required, the lowest acceptable standard can be used. However, a better option is to prepare and adopt a smelting plan that is close to zero defects.

2. Avoid turbulent inclusions on the free liquid surface

This requires avoiding excessively high flow velocity at the front free surface (meniscus). For most metals, the maximum flow rate should be 0.5m/s. Meanwhile, for closed gating systems or thin-walled parts, the maximum flow rate will be increased appropriately. This requirement also means that the drop height of the molten metal cannot exceed the critical value of the “static drop” height.

 

3. Avoid laminar inclusions of surface condensate in molten metal

This requires that during the entire filling process, there should be no front end of any metal flow to stop the flow in advance. The liquid metal meniscus in the early stage of filling must be kept in a movable state, and not affected by the thickening of the surface condensate, which will become part of the casting. Thereupon, to achieve this effect, the front end of the molten metal can be designed to continuously expand. In practice, only the “uphill” ante bet can achieve a continuous ascent process. (For example, in gravity casting, flow upwards from the bottom of the sprue). This means: bottom injection gating system; no “downhill” form of molten metal falling or slipping, no large-area horizontal flow and no front-end flow stop of molten metal due to dumping or waterfall flow.

 

4. Avoid air pockets

Avoid air bubbles generated by the pouring system from entering the cavity. It can be achieved by the following methods: reasonable design of stepped sprue cups; reasonable design of straight runners to fill up quickly; reasonable use of “dams”; avoid using “well” or other open gating systems; use small cross-section runners or the sprue uses ceramic filters near the junction of the runner; uses a degassing device; do not interrupt the pouring process.

 

5. Avoid sand core pores

Avoid the bubbles generated by the sand core or sand mold from entering the molten metal in the cavity. The sand core must ensure a very low air content, or use proper exhaust to prevent the sand core pores. Unless you can ensure complete drying, you can not use clay-based sand core or mold repair glue.


6. Avoid shrinkage

Due to the influence of convection and the unstable pressure gradient, castings with thick and large cross-sections cannot achieve upward feeding. Therefore, it is necessary to follow all the feeding rules to ensure a good feeding design. At the same time, use computer simulation technology for verification, and actually cast samples. Control the flash level at the junction of the sand mold and the sand core, the thickness of the mold coating (if any), and the alloy and mold temperature.

 

7. Avoid convection

Convection hazards are related to the setting time. Both thin-walled and thick-walled castings are not affected by convection hazards. For medium-thickness castings: reduce convection hazards through casting structure or technology; avoid upward feeding; turn over after pouring.

 

8. Reduce deflection

Prevent segregation and control it within the standard range, or the area allowed by the customer to exceed the limit. If possible, try to avoid channel segregation.

 

9. Reduce residual stress

Do not quench the light alloy with water (cold water or hot water) after solution treatment. If the casting stress does not seem large, polymer quenching media or forced air quenching can be used.

 

10. Given reference point

We must give all castings a positioning datum point for dimensional inspection and processing.

 

Yide casting is a leading casting foundry in China, with 27 years’ experience, produces top quantity ductile iron castings. If you are interested in our casting fitting, please send us a drawing file, and feel free to get a quite quote.

JM water to air heat exchanger

The History and Development of Heat Exchangers

  •  History and development

Plate heat exchangers appeared in the 1920s and mainly in the food industry. The heat exchanger made of plate instead of tube has compact structure and good heat transfer effect. Therefore, it has gradually developed into various forms.

In the early 1930s,

Sweden made the spiral plate heat exchanger for the first time. Then the British used brazing to produce a plate-fin heat exchanger made of copper and its alloy materials. And it usually appeared in the heat dissipation of aircraft engines.

In 1926,

the British Alston Chun used the indoor return air and outdoor fresh air which is positively intertwined. Due to the temperature difference and water vapor partial pressure difference between the airflows on both sides of the flat partition, simultaneous heat and mass transfer between the two air streams, causing a total heat exchange process. Through heat exchange to achieve indoor and outdoor air circulation, built-in blower and exhaust fan. The two-way equal amount takes place of the built-in blower and exhaust fan. Thus suppress the change of room temperature and keep enough fresh air indoors.

At the end of the 1930s,

Sweden produced the first plate and shell heat exchanger for pulp mills. During this period, in order to solve the heat exchange problem of strong corrosive media, people began to pay attention to heat exchangers made of new materials.

Around the 1960s,

due to the rapid development of space technology and cutting-edge science, there is an urgent need for various high-efficiency and compact heat exchangers. Coupled with the development of stamping, brazing and sealing technologies, the heat exchanger manufacturing process was further improved. This has promoted the vigorous development and wide application of compact plate heat exchangers.

Since the 1960s,

in order to meet the needs of heat exchange and energy saving under high temperature and high pressure conditions, typical shell and tube heat exchangers have also been further developed.

In the mid-1970s,

heat pipe heat exchangers appeared on the basis of research and development of heat pipes, so as to strengthen heat transfer.

heating part

  • Heat exchangers fall into three types according to different heat transfer methods.

1. Hybrid type

Hybrid heat exchanger is a heat exchanger that exchanges heat through direct contact and mixing of cold and hot fluids. Since the two fluids must separate in time after mixing and heat exchange. This type of heat exchanger is suitable for heat exchange between gas and liquid.

For example, in the cooling water towers in chemical plants and power plants. we usually spray hot water from top to bottom, while suck cold air from bottom to top. On the surface of the water film of the filling or the surface of droplets and water drop, hot water and cold air contact with each other for heat exchange. Then, the hot water is cooled, the cold air is heated, and then separated in time by the density difference between the two fluids.

2. Recuperative type

The cold and hot fluids of the recuperative heat exchanger are separated by solid partition walls and exchange heat through the partition wall. Therefore, it is also called surface heat exchanger. This type of heat exchanger is the most popular one.

3. Regenerative type

Regenerative heat exchanger is a heat exchanger that uses cold and hot fluid to alternately flow through the surface of the regenerator (filler) to exchange heat. For instance, the regenerator for preheating air under the coke oven. This type of heat exchanger is suitable for recovering and utilizing the heat of high-temperature exhaust gas.

 

Yide casting is a leading casting foundry in China, with 27 years’ experience, produces top quantity heat exchangers. If you are interested in our casting fitting, please feel free to get a quite quote.

When was Cast Iron Invented?

The Cast iron was invented by the Chinese in the 4th century BC.

China had begun to use blast furnaces to cast iron in at least the 4th century BC. Meanwhile Europe did not have such similar technology in the 7th century. The highly developed cast bronze during the Shang and Zhou dynasties provided the premise for the invention of cast iron technology. The development of the casting industry manifested as the increase in production capacity. In the meantime, the strengthening of fossil fuel preparation, furnace building, and model manufacturing technology also give evidence to it.

The first iron castings were similar in shape to similar bronze castings.

Early cast irons were white iron with high carbon and low silicon, brittle and hard, and easy to break. With the development of agricultural production, ductile cast iron occurred in the early stage of the Warring States period. As a result, the production tools can be made by cast iron. Through decarburization and graphitization heat treatment, we can obtain black and white core ductile cast iron with incomplete decarburization respectively. After the middle Warring States period, cast iron tools gradually replaced other tools, such as wood, stone and copper. Therefore, cast iron tools became the main production tools. The unearthed objects included shovel, sickle, adze, axe, plow, shackle, chisel, etc.

Because of the large demand for ironware, cast iron also contributed to the invention of Tiefan (cast iron metal mold).

In 1953, Tiefan used to cast iron axe, sickle and vehicles was unearthed from the Casting Site in Xinglong, Hebei. These iron castings have uniform wall thickness, reasonable structure, uniform shape and casting outline. At the same time, some iron mold can cast two objects at a time. This shows that casting iron technology has reached a fairly high level during this period.

Iron castings was widely used as farm tools in the late feudal society.

In the 10th century, it was possible to cast extra-large iron castings weighing 50 tons. After the Five Dynasties, iron buildings increased, such as the iron tower of the Northern Song Dynasty in Dangyang, Hubei. During the Tang and Song Dynasties, the iron in Hunan, Guangdong, Hubei, Fujian was known for its excellent quality. Furthermore, iron smelting production developed rapidly. Foshan, Guangdong has become a well-known smelting and casting center. The iron pots are exported to Southeast Asia, and traditional cast iron techniques such as clay casting and casting pots are still used in modern times.

Cast iron is an important invention of the working people in ancient China. Cast iron played a major role in the development of Chinese civilization and had a considerable impact on later generations.

Yide casting is a leading casting foundry in China, with 27 years’ experience, produces top quantity ductile iron castings. If you are interested in our casting fitting, please send us a drawing file, and feel free to get a quite quote.

Diagnosis Method of Hydraulic System Failure of Forklift

The hydraulic system is the core of the manual hydraulic forklift. In that way, if there is a malfunction in daily use, how should we check and diagnose it. Today, I will introduce you to three basic methods.

1. Visual inspection method

For some relatively simple faults, we can inspect parts by means of sight, hand model, ear hearing and smell.

For example, visual inspection can find faults such as cracks, oil leakage, loosening and deformation. In order that parts can be repaired or replaced in time. Holding oil pipes (especially rubber pipes) by hand, there will be vibration when pressure oil flows through; but there is no such phenomenon when there is no oil flow or the pressure is too low.

In addition, hand touch can also be used to judge whether the lubrication of hydraulic components with mechanical transmission parts is good.

Feel the temperature change of the component housing with your hands. If the component housing is overheat, it means that the lubrication is poor. Ear listening can determine the point of failure and the degree of damage.

For example, hydraulic pump suction, overflow valve opening and component issuance will produce abnormal sounds such as water impact or “water hammer sound”. Some parts will emit peculiar smell due to overheating, poor lubrication and cavitation. We can use nose sniffing in this condition.

 

2. Replacement diagnosis

We can use this method when there is a lack of diagnostic equipment at the maintenance site, or the components are more precise and not suitable for disassembly. Firstly,  remove the component suspected to be malfunctioning.

Secondly, replace it with a new one or another component of the same model that works normally on the machine for testing.

And then the diagnosis can be made by seeing whether the fault can be eliminated. Although this method is restricted by the structure, on-site component storage or disassembly inconvenience and other factors.

Besides, it may be troublesome to operate. However, it is convenient to use this method for components that are small in size and easy to disassemble, such as balance valves, overflow valves, and one-way valves.

The replacement diagnosis method can avoid the performance degradation of hydraulic components due to blind disassembly.

If you do not use this method for the above failures, and directly remove the suspicious main safety valve and disassemble it.  Its performance may be affected after re-installation, if there is no problem with it.

3. Instrument inspection method

The instrument inspection method is to judge the fault of the system by measuring the pressure, flow and oil temperature of each part of the hydraulic system.

In general on-site inspections, the failure of the hydraulic system is often manifested as insufficient pressure, which is easy to detect. While the detection of flow is more difficult. The size of the flow can only be roughly judged by the speed of the actuator. Therefore, in-field testing, we can use more methods to detect system pressure.

Yide casting is a leading casting foundry in China, with 27 years’ experience, produces top quantity forklift parts. If you are interested in our casting fitting, please send us a drawing file, and feel free to get a quite quote.

How to Choose, Install and Maintain Ductile Iron Pipe

How to Choose, Install and Maintain Ductile Iron Pipe

Firstly, let’s see why choose ductile iron pipe.

In building construction, especially the construction of urban water supply pipeline network, the pipeline products used require high strength, high toughness, strong corrosion resistance and comprehensive cost of construction and installation. From these perspectives, ductile iron pipe is undoubtedly the best choice. From the production process of ductile iron pipe to the final construction and installation, it meets our requirements. No matter how complicate the project, choosing ductile iron pipe as the main pipeline product is definitely a wise choice with the highest cost performance in the long term.

Secondly, the installation of ductile iron pipe mainly includes the following steps:

1. Site selection

Select the installation route of the ductile pipe from the perspective of soil quality and nearby pipelines, and form construction drawings. Special attention should be paid to avoid some corrosive and unsafe installation routes.

2. Pipe laying

Use Large-scale equipment such as excavators and hoisting machines in the pipe laying process. At the same time, a 10-meter ductile pipe should arrange 2 to 3 workers based on experience. The rubber ring should be placed in the socket groove and compacted by hand.

3. Determine the distance of the pipeline

The key of this step is to cut off the iron pipe if it’s too long. And process the spigot end into a groove shape according to the construction angle to facilitate application.

4. Tube body measurement

Through the measurement of the tube body, to demtermine the straight line space and the corner space formed by the installation radian, vacancy, and transfer. Thus in order to achieve stability and avoid displacement.

5. Positioning marking

The purpose of the positioning marking is to achieve that the fixed pipe and moving pipe axis lines are on the same straight line as a wheelbase. This step is to ensure the quality and speed of the installation. Also it helps to prevent the pipeline apron from falling off and affecting the quality and progress.

6. The installation of pipes should be flat, and the pipes should be in a straight line. Besides, be careful of inclination angle.

7. Align the interface of the connecting pipe with the socket. If the insertion resistance is too large, do not insert it forcibly to prevent the rubber ring from twisting.

8. When pipeline installation and laying works are interrupted, use its cap to close the pipe opening to prevent dirt, sand and other debris from entering the pipeline.

9. Cover the middle part of each pipe with soil before the pressure test.

Then, how to maintain ductile iron pipes? Let me introduce to you briefly.

The maintenance of the ductile tube should always start from its selection. Before the project starts, we should perform a visual inspection of the parts, such as pipe fittings, aprons, elbows, etc., so as to avoid using defective parts.

The second point of maintenance is to check and acceptance check. We should pay attention to the socket apron lower tube (pipe) that affects the long-term stable operation, and strive to have no debris in the socket in these aspects. The rubber ring has been hit by a rubber hammer without warping and twisting, and is evenly stuck in the groove.

During the maintenance process of ductile iron pipes, since the axis of the moving pipe is deeply buried in the ground, be careful when there is an inclination angle. If the resistance is too large, do not excavate forcibly to prevent the rubber ring from twisting. The maintenance of ductile tubes in winter also needs preheating with hot water to reduce the hardness and install quickly.

In addition, if the quality of the ductile iron pipes used in the project absolutely meets the national standards, then we should pay attention to the apron, welding, etc. AC and DC. As long as the ductile cast iron pipes are applied properly and the product quality is excellent, it can reduce unnecessary troubles in installation projects. Also, as a new type of pipe material, its future maintenance work is relatively easy.

Yide casting is a leading casting foundry in China, with 27 years’ experience, provides quality duction iron pipe, brass pipe in a big production, OEM service is available, if you are looking for a casting supplier, please don’t hesitate to contact us. Of course, you are welcome to visit our casting factory in China.

Features and Process Application of Sand Casting

Features and Process Application of Sand Casting

Sand casting uses clay-bonded sand as a modeling material to produce castings. It is a process with a long history and  most widely used.

Yide Casting automatic sand casting from China

Yide Casting automatic sand casting

Sand casting has a long history, dating back thousands of years. In terms of its scope of application, sand casting is everywhere in the world.

It is worth noting that, with the vigorous development of various chemically bonded sands today, green sand is still the most important modeling material. Its wide application range and high consumption are beyond comparison with any other modeling materials. According to reports, more than 80% iron castings in the US use green sand, and more than 73% in Japan.

The extremely strong ability to adapt to modeling conditions is also a major feature of green sand. In 1890, the jolt squeeze moulding machine came out. Green sand, which has been used for manual moulding for a long time, was extremely successful in machine moulding. This furthermore laid the foundation for the mechanization and automation of subsequent moulding operations. The modern high-pressure moulding, jet-pressure moulding, air-punching moulding, static pressure moulding and non-shock vacuum pressure moulding and other new technologies are also based on the use of green sand.

The implementation of various new processes has made green sand more important in casting production. Besides, green sand is also facing many new problems. This urges us to continuously strengthen the research and understanding of the green sand.

Nowadays, with the rapid development of science and technology, the demand for castings in various industrial sectors is increasing. At the same time, the requirements for the quality of castings are getting higher and higher. In modern foundries, the productivity of molding equipment has increased to an unprecedented level. If the performance of the molding sand cannot be fully adapted to the specific production conditions, or the stability and consistency of the molding sand cannot be effectively controlled, it will not take long for the foundry to fail.

With the development of science and technology, foundries that use green sand generally have sand treatment systems suitable for their specific conditions, including old sand treatment, new sand and auxiliary materials, sand mixing, and sand performance monitoring.

There are many constantly changing factors in the green sand system. For example, if one or several key properties cannot be kept within the control range, problems may occur in production. An effective sand processing system should be able to monitor the performance of the sand. At the same time, if there is any problem, the system should be able to correct it in time.

Due to the different arrangements of sand treatment systems and equipment used in various foundries, it is impossible to draw up a set of general control methods. Here, I intend to put forward some control points that have been widely recognized. After carefully understanding these points, each foundry can determine feasible control methods according to its own specific conditions. Moreover, with the advancement of technology and the actual capacity of the factory (including personnel and funds), the control of the molding sand system must be continuously improved.