A press brake is a piece of manufacturing equipment that is used to bend sheet metal. A press brake is typically narrow and long so that large pieces of sheet metal can be bent by it. A press brake bends sheet metal by lowering a punch onto sheet metal that has been positioned on top of a die. The metal may be bent several times by a press brake until the desired form has been achieved. Press Brake,Cnc Press Brake,Metal Bending Machine,Hydraulic Press Brake Jiangsu Hoston Machine Tools Co., Ltd. , https://www.hostoncncs.com
Press brakes can make a variety of different bends on many different types of metals. When setting up a bending process, it is important to consider the metal type being bent, the die, the punch, and the bending force.
The metal type is important to understand because of the differing physical properties among metals. For instance, a high carbon steel will generally be less bendable by a press brake than many aluminum alloys because of the differences in ductility and strength. Metals typically have a recommended minimum bend radius that the material can be bent to without damaging it.
The die and the punch used on the press brake both have a large impact on the bending process. The die is hollow material that the metal is placed on top of prior to bending. It is a very hard and strong material that is near in shape to the desired shape of the metal being bent. The punch is a solid material that is lowered down onto the metal. Since the pressing action of the punch onto the metal and the die are what causes the metal to bend, both shapes must be accurately suited to the bending job. The correct metal shape following a press brake operation is dependent on the size and shape of the punches and dies. The dies and the punches are typically designed in such a way that they can be interchanged easily to accommodate a wide array of jobs.
Valve flow coefficient and cavitation coefficient is an important parameter of the valve
Valve flow coefficient and cavitation coefficient is an important valve parameters, which are generally available in the advanced industrial countries, the valve material, even in the sample also printed. China's production of the valve is basically no information in this area, because access to this information need to do experiments can be made, this is our country and the world's advanced level of the valve one of the important performance gap. 3.1 Flow coefficient of the valve Flow coefficient of the valve is a measure of the flow capacity of the valve. The larger the flow coefficient, the smaller the pressure loss when the fluid flows through the valve. According to KV calculation formula: KV-flow coefficient Q-volume flow m3 / h ΔP-valve pressure loss bar P-fluid density kg / m3 ?? 3.2, the valve cavitation coefficient? Gas Erosion coefficient δ value, to select the control flow, choose what kind of valve structure type. Where: H1 - the pressure after the valve (outlet) m H2 - the difference between the saturated vapor pressure corresponding to the atmospheric pressure and its temperature m ΔP - the differential pressure before and after the valve m? The various cavities allow for the cavitation coefficient δ is also different. as the picture shows. If the calculated cavitation coefficient is greater than the allowable cavitation coefficient, then it is available and no cavitation will occur. If the butterfly valve allows a cavitation coefficient of 2.5, then: • If δ> 2.5, cavitation does not occur. When 2.5> δ> 1.5, slight cavitation can occur. When δ <1.5, vibration occurs. δ <0.5 continued to use the case, it will damage the valve and downstream piping. The basic characteristics of the valve and operating characteristics of the valve, the valve cavitation occurs at a time when it is out of sight, not to mention that at that point to reach the operating limit. Through the above calculation is clear at a glance. Therefore, cavitation occurs because the liquid accelerates the flow through a section of the tapered section, the part of the liquid gasification, the resulting bubble followed by the valve after the open section burst, the performance of three :? (1) the occurrence of noise (2) vibration (In severe cases, it can cause the destruction of foundation and related structures, resulting in fatigue fracture.) (3) Material damage (erosion of valve body and pipeline) • From the above calculation, it is easy to see that cavitation and post-pressure H1 There is a great relationship, increased H1 will obviously change the situation, to improve the method:? A. The valve installed in the pipeline lower. b. Install the orifice plate on the pipe behind the valve to increase the resistance. c. Valve outlet is open, direct reservoir, so that the bubble burst space increases, reduced cavitation. ? Comprehensive analysis of the above four aspects, discussion, summed up the gate valve, butterfly valve main features and parameter list easy to use. Two important parameters in the valve operation