2、 Advantages of dual-use fixture for machining external spherical surface and internal pneumatic ball valve: when the link between the connecting rod and the upper and lower rods is removed, it will not affect the continued use of the square tool holder for other processing (such as the turning plane of the valve body, the turning outer circle and inner hole of the valve core); It is easy to disassemble and assemble, and the size of the inner and outer spherical surfaces processed by the same connecting rod can be consistent; Connecting rods composed of series sizes can be used for processing adhesive film cocks of different sizes or other spherical surfaces; The taper shank of tailstock with different taper and size can also be used for lathes of different models and specifications, with a wide range of applications; After removing the tailstock taper handle 7, the valve core can also be drilled and tapped. This tool is simple in structure and manufacture.

Welding technology and application of teflon hose joint for teflon compensator
Joint structure and brazing characteristics
Teflon hoses are widely used in thermal power plants to escort fuel oil, insulating oil and turbine oil. Due to the high pressure and temperature of the medium delivered by the hose, leakage or desoldering at the welding position will cause serious accidents. There are two layers of PTFE hose, the inner layer is Φ 2O × 2mm hose. The outer layer is braided fine steel wire mesh. Both layers are made of 1Cr18Ni9Ti. The hose is mainly used for sealing, and the fine steel wire mesh is used for strength maintenance. Recently, the hoses consumed by the manufacturer have three ways (spiral integral, roll welding and brazing). Since the PTFE hoses on power plant boilers are subject to high temperature and pressure during operation, they are often subject to bending stress, so spiral integral hoses are recommended. After the hose is transported to the site, a stainless steel short pipe joint is added to the hose. At the same time, a stainless steel outer ring is added to the thin steel wire and the brazing is stopped. The brazing seam must ensure the tightness and the accepted turn force of the pipe during operation. The structure of brazing has the following characteristics: the shape of brazing seam wall is complex, with corrugated, fine steel mesh, etc., as shown in Figure l. In order to ensure the tightness and load-bearing ability of brazed joints, the requirements for brazing quality are high, and there is sufficient stability in batch consumption. Because corrugated hose and fine steel wire mesh are thin and thin, manual brazing with oxyacetylene fast flame is very easy to form overheating. When the temperature exceeds 830C, chromium and titanium oxides with strong stability are generated and are not easy to remove, making brazing almost impossible to stop, so it is requested to avoid oxidation during brazing. In the welding consumption theory, because of its special structure and adverse factors, it is often difficult to meet the design and process requirements with oxy ethylene fast brazing. In order to properly deal with this problem, we adopt a new arc brazing process for the tetrafluoro compensator. That is, when the arc brazing of the condensation plate is stopped under the maintenance of inert gas, the arc is located between the workpiece and the condensation pole, and the maintenance gas is around. As an electrode of the arc, solder is continuously fed into the brazing area from the welding gun to form the filler metal of the brazing weld. The characteristics of condensation arc brazing are low melting point of brazing filler metal (2 silver brazing filler metal melting point is 860-900 "C), high mechanical strength, and small welding heat affected zone. It is unnecessary to use brazing filler metal that may cause corrosion during brazing. It is unnecessary to clean after welding. The equipment operation box is used to complete automation.
Metallographic structure analysis of tetrafluoro hose
Metallographic analysis of the arc brazed joints of carbon steel and stainless steel was carried out. After further observation and analysis by SEM and EDS, the scanning morphology of the brazed joints was basically the same as that of the metallographic structure. Through X-ray energy spectrum, it can be clearly seen that the brazing filler metal is transiting to the weldee during brazing, and the transition zone is formed at the junction of the brazing weld and the workpiece. A shell belt or a black belt is shown on the metallographic structure diagram and the scanning electron microscope. At the same time, it can also be observed that the metal elements in the workpiece are gradually diffusing to the brazing seam.
The application of Teflon hoses in the thermal power field is mainly represented by the gas water heater in thermal power plants. The circulating water is heated to a certain temperature by the steam from the thermal power plant passing through the PTFE hose. For example, heating to about 150 ℃ is called a high temperature heater, and heating to about 110 ℃ is called a basic heater. The teflon compensator then supplies circulating water to thousands of households to deal with the heating problem of residents in winter. This combined heat and power supply mode can not only save energy, but also improve the living environment of urban residents and obtain good social benefits.
In recent years, the establishment of cities in China has been carried out rapidly. With the progress of people's life and death level, the living level of people is also improving from time to time, which is bound to increase the living area. The large increase in living area makes the heating ability of the original heater of the power plant look inferior, which requires an increase in the heat exchange area, but the space of the plant in the power plant is certain, so the use of corrugated tube heat exchanger instead of the original shell and tube heat exchanger completely solves the above problems.
The application of tetrafluoro hose in the petroleum industry The petroleum industry is the pillar industry of our national economy, and its development is bound to have a strong role in promoting the national economy. Therefore, it is an imperative task to comprehensively implement energy-saving technology in the petroleum industry.
Generally speaking, crude oil pumped from the ground has a very high viscosity. It requires a lot of propulsion to escort crude oil from the well platform to the far center. However, if the viscosity of crude oil is reduced, it will be much easier to escort crude oil. One way is to raise the temperature of crude oil. Previously, an oil field used a gas furnace to heat crude oil, which not only consumed a lot of natural gas, but also had low practical efficiency, resulting in a large waste of energy. Since the bellows heat exchanger is used on the well platform, it not only saves energy, but also achieves good results. The method is to install small Teflon hoses on each oil well. The crude oil is allowed to pass through the pipes, and the hot water from the boiler room is introduced between the pipes. In this way, the crude oil is heated from about 20 ℃ to about 50 ℃, and the viscosity of the crude oil drops significantly. Moreover, a boiler room can drive many bellows heat exchangers, and hot water circulates between the boiler and the bellows heat exchanger.
Application of tetrafluoro hose in the chemical industry Chemical industry is one of the most widely used areas of heat exchangers. Large chemical plants have thousands of heat exchangers, but these heat exchangers are shell and tube heat exchangers. The process characteristics of chemical plants are heating and cooling, reheating and cooling. An oil refinery in Xinjiang uses bellows heat exchangers to condense organic steam into liquid, and another chemical plant uses bellows heat exchangers as reboilers to heat organic mixed substances to 90 ℃, so that they become mixed steam, and then enter the tower for cooling, cycle by cycle. Some chemical plants also use bellows heat exchangers to heat the medium to a certain temperature, and then enter the reaction tower to stop the chemical reaction.
Although tetrafluoro hose has been used in chemical industry, its dosage is small, and it belongs to the stage of experiment and observation. And the place used is not very important. It will take time for bellows heat exchanger to completely replace shell and tube heat exchanger. There are objective and objective elements here. Objectively, this new product of bellows heat exchanger still has some needs to be improved, and there is still much work to be done, which limits the large-scale promotion and application of this product in the chemical industry.
The application of tetrafluoro hose in residential liquefied petroleum gas The bellows heat exchanger was used in the heating system of liquefied petroleum gas since 1992. A gas company has adopted two sets of external diameter? 325mm, heat exchange area is 5m? A small bellows heat exchanger is used to accelerate the gasification of liquefied petroleum gas for urban residents. Its heating source is 70 ℃ hot water, with the working pressure of 0.3MPa. The hot water runs on the tube side and the liquefied petroleum gas runs on the shell side. A liquid baffle is added at the outlet of the liquefied gas. The liquid level of the liquefied gas is at 1/2 of the shell. The remaining heat exchange area is mainly used to further vaporize the liquid carried in the vaporized liquefied gas. If there is still liquid carried in the liquefied gas, it is recovered by the liquid baffle at the outlet and flows back to the bottom of the shell along the shell wall, so that the liquefied gas can be fully gasified. Since the use of bellows heat exchange tubes, satisfactory results have been obtained. 5. The application of corrugated tube heat exchanger in light industry The PTFE hose also has a broad application prospect in light industry. Bellows heat exchanger was used to cool beer juice in a brewery. The cooling medium is liquid ammonia, and its temperature is - 5 ℃ - - 6 ℃. Liquid ammonia works in the shell side. The cooling medium is beer juice, the inlet temperature is 13 ℃, and the outlet temperature is 1 ℃ - 2 ℃. Beer juice works in the tube side, and its workflow is shown in Figure 6-34. When beer juice enters the heat exchanger, it will release heat. When the temperature drops to 1 ℃ - 2 ℃, it will be stored in the wine storage tank for later use. At the same time, liquid ammonia absorbs the heat of beer juice and evaporates. The evaporated ammonia is compressed by a compressor to form liquid ammonia at - 5 ℃ - 6 ℃, and then enters the heat exchanger to complete a cycle. 6 Application of Teflon hoses in urban central heating In recent years, many cities in China have established a number of residential quarters according to the demand for energy conservation and environmental maintenance, and accordingly put forward the policy and criterion of regional central heating in terms of heating, which has greatly promoted the rationalization and modernization of urban central heating. Central heating has become a hot spot in the establishment of large and medium-sized cities.