Cause Analysis and Treatment of Leakage of Hydraulic Flange

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Cause Analysis and Treatment of Leakage of Hydraulic Flange

In case of flange leakage, the following factors are usually considered:

(1) Leakage caused by ineffective sealing due to loose flange fastening bolts. Retighten the bolts and make anti loose marks at the bolts.

(2)  Cracks and damages of flange connecting pipes due to overpressure, life fatigue or unqualified materials. In this case, a new qualified flange shall be used for replacement. If it is a welding flange, it shall be cut and re welded.

(3) The flange mounting end face or flange sealing end face is not smooth enough, or there are scratches, resulting in the seal ring can not be effectively sealed. The mounting surface or flange sealing surface shall be repaired to achieve proper roughness.

(4) The seal ring is damaged due to the wrong installation method. Replace it with a new one.

(5) Seal life is too short due to improper selection of seal ring. Considering the service life requirements, working pressure, acid and alkali environment, and the impact of high temperature on the seal ring, select the appropriate seal ring.

Decho is a professional supplier on hydraulic components ,if you have any request,pls do not hesitate to contact us by email [email protected]

What are the characteristics of aluminum screws?

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Although aluminum screws are less used than screws made of other materials, aluminum screws also have a market demand. Today we will talk about the characteristics and application fields of aluminum screws.

The proportion of aluminum screw is only one third of that of iron. It is a metal material with extremely light weight and good conductivity, thermal conductivity and ductility. In addition, aluminum alloy can obtain the same hardness as steel, so it can be used when both high strength and light weight are required. Although aluminum screw is far from being popularized, it has unique properties in aviation, medical and other related fields, It is used more and more widely. Next, we will introduce several representative aluminum alloys for screw production. It should be noted that model x refers to the model in JIS.

1. Aluminum copper alloy screw [Model 2000]

After heat treatment, aluminum copper alloy is an alloy with superior strength and hardness, including A2017 (hard aluminum) and a2024 (super hard aluminum) with higher hardness. Because it contains copper, it has poor corrosion resistance.

2. Aluminum magnesium alloy screw [model 5000]

Aluminum magnesium alloy is the aluminum alloy with the best corrosion resistance and good processability. Although it has medium strength, it has a good balance of mechanical properties. Therefore, it is a widely used aluminum alloy. Representative models include a5005 and a5052

3. Aluminum magnesium zinc alloy screw [model 7000]

Aluminum magnesium zinc alloy is one of the strongest aluminum alloys, among which A7075 [superhard aluminum] is used in aircraft manufacturing and other fields. However, the corrosion resistance of this series of aluminum alloys is poor.

The tensile strength of SS400, a representative steel in aluminum screws, is 400MPa. Among aluminum alloys, A2017, a2024, A7075, etc. are harder than SS400, while aluminum alloy a5052 with the best corrosion resistance is slightly inferior in strength.

Although the utilization rate of aluminum screws is not as high as that of other materials, it is undeniable that aluminum screws have certain advantages in performance. When choosing the screw material, we can choose the screw material according to the actual use needs. If you have any questions or want to know more about aluminum screws, please contact us by email [email protected] or call us by 0086 18920150762

Why do more and more people use TPR casters?

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Now more and more users in the market are more and more fond of TPR casters. We see more and more TPR casters in factories, hotels and life. It also gradually appears in everyone’s vision and has become a good partner and helper in our life. Let me give you a brief introduction of why TPR can become a new caster in the fierce market.

Introduction to TPR casters:

1. Thermoplastic elastomer TPR compound has become an important raw material in castor and wheel industry because of its convenient processing and molding (it can be directly molded by injection molding machine), excellent wear resistance, elasticity, shock absorption and low noise.

2. Common casters, such as shelf wheels and cart wheels, are made of hard plastic (such as PP, PA) and soft plastic (such as TPR, TPE, PU, EVA, TPU). As the framework material of casters, hard plastic plays the role of load-bearing, while soft rubber plays the role of anti-skid, shock absorption and noise reduction.

3. At present, TPR caster manufacturers generally mainly use hard plastic copolymer PP, some use PA nylon, and soft plastic uses TPE. TPR accounts for a large proportion of market demand This kind of castor is usually processed by two – step injection molding That is, the first step is to inject hard plastic parts PP or PA; The second step is to put the formed hard plastic part into another set of mold, fix the position, and then shoot and stick the soft plastic TPR to the position where the hard plastic part needs to be covered.

TPR caster benefits:

1. Hardness 55a-95a;

2. Quiet operation without noise interference;

3. And PP have excellent adhesion;

4. Good shock absorption, anti-skid and wear resistance;

5. High bearing capacity, high wear resistance and high resilience;

6. Good UV resistance and chemical resistance;

7. Leave no trace on the floor, unlike the rubber wheel, there will be sulfur and carbon black precipitation;

8. Excellent wear resistance and pullout elasticity, UV resistance and ozone resistance;

9. Weather resistance and no erosion, which can be applied to all kinds of harsh and extreme environments at home and abroad;

10. Wide temperature resistance range, allowing long-term use of the temperature range between – 50 ~ 115 ℃;

Its advantages are not only mentioned above, but also used in hotels, factories and workshops. The application scope of TPR casters is not limited to these fields; Of course, we need to explore and discover its good performance and advantages that have not been mentioned.

Tianjin Decho is a professional supplier of TPR casters . If you need any , pls do not hesitate to contact us by email [email protected]

Shopping Cart Casters

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In the supermarket, we often see a tool – shopping cart. Shopping cart is the most common tool in the supermarket. Its existence is to help people easily load and move items in the shopping process. Its most important part is the caster at the bottom. It can be said that the caster of shopping cart is the core part of the whole shopping cart. If it is less, it will lose the labor-saving effect. Heavy loads, high barriers, and the great differences between the cold storage area and the store counter all put forward high requirements for shopping cart casters.

The flexible movement of shopping cart is due to the installation of casters, which include fixed casters and movable casters. Among them, the movable caster is also known as the universal wheel. Its remarkable feature is that it can rotate 360 degrees horizontally and drive in any direction. The flexibility of universal wheel is inseparable from its structure, so what parts does it consist of?

① Single wheel: a single wheel is a wheel

② Movable support assembly: the movable support assembly is composed of movable support, axle, nut, screw or inserting rod, excluding wheel, inner wheel bearing and shaft sleeve.

③ Shaft sleeve: the shaft sleeve is a non rotating part made of steel sleeved outside the axle, which is used for the wheel bearing to rotate and fix the wheel in the support, and the shaft sleeve needs to be equipped with a rotating shaft.

④ Rotating bearing:

A. Single layer bearing: there is only one layer of steel ball on the large track, commonly known as single row ball bearing;

B. Double layer bearing: also known as double row ball bearing, it has double-layer steel balls on two different tracks;

C. Economical bearing: it is composed of steel ball supported by upper ball plate formed by stamping;

D. Precision bearing: it is composed of standard industrial bearing.

⑤ Center rivet:

The center rivet is an integral part of the base plate and is used to fix the bolts or rivets of the rotating device. Tightening the bolt type rivets can adjust the looseness of the universal wheel caused by rotational wear.

With the development of modern commerce, there are more and more kinds of goods. Usually when people need to buy many kinds of goods, people tend to choose to go to large supermarkets with a wide range of goods, such as Carrefour, Wal Mart, RT mart and so on. These large supermarkets are basically equipped with shopping carts, because shopping carts are flexible and can provide great convenience for customers to carry goods. Therefore, the selection of shopping cart casters is particularly important, because it can directly affect the service life of shopping cart.

Decho is a professional supplier on Casters for Shopping Cart . If you need any for your supermarket applications, pls feel free to contact us by email [email protected]

Detailed explanation of knowledge points on spring damping castors

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For the use of casters, when we pay attention to its load-bearing, we should also pay attention to another aspect of its performance, that is, its shock absorption. For some textile and clothing types, there are often no such requirements when using casters, but if it is an industrial place in the electronic and electrical industry, it is often necessary to meet these requirements when using them. Because if there is no shock absorption, the whole product will be greatly damaged by handling. In terms of shock absorption of casters, the first thing to pay attention to is its design on the wheels, and now there are often many types of wheels.

Support features:

The support adopts 4-station automatic carbon dioxide protection welding technology, which has high strength and impact resistance, and adopts environmental protection galvanizing treatment. The salt spray test has reached the national level 6 standard; The destructive and torsion test and hydrochloric acid melting point test are carried out according to European regulations and national standards, which can fully meet the specified standards.

 

Product advantages:

1、 Easy start. Caster spring damping wheel adopts high-quality iron core wrapped polyurethane wheel, which has good toughness, elasticity and wear resistance. When installed on the equipment vehicle, the starting power is small (for example, 6-inch shockproof wheel, when the single wheel load is 200kg, the starting power is 3.6kg force);

2、 Resistant to high-speed driving. The caster wheel disc adopts double tapered roller bearings, which can better prevent the wheel from shaking in the process of high-speed traction, greatly reduce the noise and provide a quiet production environment for the production workshop.

3、 Sealing, dustproof and anti winding performance. The anti-seismic spring of the anti-seismic damping wheel is completely sealed, with good dust-proof and anti entanglement, which is suitable for different choices and requirements.

4、 Shockproof performance. The spring caster adopts high-quality impact resistant and anti-seismic spring and large track diameter bead disc, and the bottom plate and upper and lower bead discs are heat treated, which can greatly improve the hardness and toughness of the bead disc, make the bead disc rotate more flexibly and easily, greatly improve the stress performance and avoid the damage of the wheel caused by vibration on the concave convex ground.

Scope of use:

Kitchen equipment, mechanical equipment, heavy field operation platform, material handling vehicle, heavy frame, heavy storage equipment, heavy tool vehicles, etc.

Single wheel features:

The material is high elastic polyurethane, which can be used indoors and outdoors. The wheel surface is slightly circular, which is flexible and light. Similar products are generally polychlorinated or polyether. In contrast, this product has better toughness, strong adhesion fastness, no degumming, no cracking, wear resistance, compression resistance and other capabilities after special treatment, and is environmentally friendly and non-toxic. Polyurethane injection is a polyurethane elastomer injected through chemical injection, It is based on polyester polyol diisocyanato ethylene glycol. Protective floor, traceless, non staining, elastic, very resistant to friction and corrosion of many corrosive substances. UV resistant. But not resistant to hot water, steam, warm air and aromatic solvents.

In addition, it has a very low degree of permanent deformation, small rolling resistance and less heat when bearing dynamic load. The color is red. The applicable temperature range for pouring polyurethane: – 30 ℃ to + 70 ℃, and the maximum temperature for a short time is + 90 ℃. The rigidity is improved in the environment below – 10 ℃. Hardness 92 °± 3

Decho is a professional supplier on spring damping castors， if you need any , pls do not hesitate to contact us by email [email protected]

Process flow of making elbow

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Process flow of making elbow

Seamless elbow: an elbow is a pipe fitting used at the turn of a pipe. The proportion of all pipe fittings used in the pipeline system is large, about 80%. Generally, different forming processes are selected for elbows with different materials or wall thickness. The common forming processes of seamless elbow in manufacturers include hot pushing, stamping, extrusion and so on.

Hot push forming

The hot push elbow forming process is a process of heating, expanding and bending the blank sleeved on the die under the push of the special elbow pushing machine, core die and heating device. The deformation characteristic of the hot push elbow is to determine the diameter of the pipe blank according to the law that the volume remains unchanged before and after the plastic deformation of the metal material. The diameter of the pipe blank used is less than the diameter of the elbow. The deformation process of the blank is controlled through the core die to make the compressed metal flow at the inner arc and compensate to other parts thinned due to diameter expansion, so as to obtain the elbow with uniform wall thickness.

The forming process of hot push elbow has the characteristics of beautiful appearance, uniform wall thickness and continuous operation, which is suitable for mass production. Therefore, it has become the main forming method of carbon steel and alloy steel elbow, and is also used in the forming of some specifications of stainless steel elbow.

The heating methods of the forming process include medium frequency or high frequency induction heating (the heating ring can be multi circle or single circle), flame heating and reverberatory furnace heating. The heating method depends on the requirements of the formed products and energy conditions.

Stamping forming

Stamping formed elbows have long been used in the forming process of mass production of seamless elbows. They have been replaced by hot pushing method or other forming processes in the production of common specifications of elbows. However, in some specifications of elbows, the production quantity is small, the wall thickness is too thick or too thin.

The product is still in use when there are special requirements. The pipe blank with the same outer diameter of the elbow is used for the stamping forming of the elbow, and the press is used to directly press and form in the die.

Before stamping, the tube blank is placed on the lower die, the inner core and end die are installed into the tube blank, the upper die moves downward and begins to press, and the elbow is formed through the restraint of the outer die and the support of the inner die.

Compared with the hot pushing process, the appearance quality of stamping forming is not as good as the former; When the stamping elbow is formed, the outer arc is in the tensile state, and there is no excess metal in other parts to compensate, so the wall thickness at the outer arc is reduced by about 10%. However, due to the characteristics of single piece production and low cost, the stamping elbow process is mostly used for the manufacture of small batch and thick wall elbows.

Stamping elbows are divided into cold stamping and hot stamping. Cold stamping or hot stamping is usually selected according to the material properties and equipment capacity.

The forming process of cold extrusion elbow is to use a special elbow forming machine to put the pipe blank into the outer die. After the upper and lower dies are closed, the pipe blank moves along the gap reserved by the inner die and the outer die under the push of the push rod to complete the forming process.

The elbow manufactured by internal and external die cold extrusion process has beautiful appearance, uniform wall thickness and small size deviation. Therefore, this process is often used for the forming of stainless steel elbow, especially thin-walled stainless steel elbow. The precision of internal and external die used in this process is high; The requirements for wall thickness deviation of pipe blank are also strict.

Medium plate welding

Use the medium plate to make half of the elbow section with a press, and then weld the two sections together. This process is generally used for elbows above DN700.

Other forming methods

In addition to the above three common forming processes, seamless elbow forming also adopts the forming process of extruding the tube blank to the outer die and then shaping through the ball in the tube blank. However, this process is relatively complex, troublesome to operate, and the forming quality is not as good as the above process, so it is rarely used.