Title: Status and trends of the inter
Description: At present, the manufacturer of the valve industry in China is power diesel generator increased research and development efforts, but the product is technically out of date, making the competition must not force the production of valve varieties can only meet about 70 percent of the market demand. Shortage of low-voltage large-diameter valves and production and demand contradiction between the high pressure valve on the species and materials, as well as those in development of new products and need our valve business research real development, to expand. Competition in the market is always survival of the fittest. Speed ??up the adjustment of product structure, technology updates, new product development, the creation of the license ... is their own survival, development, accounting for the foundation of the field of domestic and foreign markets.
ZY47-16C type pressure control valve, for radiator valve , introduced its own differential pressure control valve works. Figure 1 for the structure and working principle diagram of the valve. Spring, a sense of lamination and stem consolidation with the outlet pressure P2 import a sense of laminated upper part sealed chamber through the guide pipe, a sense of laminated lower part for the inlet pressure P1. P1-P2 setting value s of (hereinafter referred to as the set pressure) to determine the pre-compression of the spring, even if the elastic spring set pressure under the condition sense of laminated spring force are equal. And in accordance with the stroke of the valve plug is much smaller than the spring pre-compression principle to select the spring. This makes the equilibrium of any opening in the valve, the valve's inlet and outlet pressure difference is approximately equal to the set pressure difference s. Strictly speaking, the opening of different of the equilibrium state is not equal. Clearly, as the opening increases, the equilibrium state is increased. But by the choice of the spring can be in the full stroke of the valve plug will balance the state s deviation of control within a certain range (for example, 10%) within.
In recent years, heating engineering, fuel and generator sets units have more applications. Metering and charging of the heating, independently regulate the flow of awareness greatly enhanced, coupled with the domestic hot water the amount of change within one day, making the flow of the heating systems have a great range. If the flow is too small, may cause local boiling of the fuel and gas-fired units, thereby enabling the unit damaged. In the air-conditioning systems, chillers, chilled water flow is too small, may also cause the evaporator coils partial freeze, thereby enabling the unit damaged. For both cases, shown in Figure 2, the installation of self-operated pressure control valve in the bypass pipeline. The user to adjust the other reasons to make the system flow decreases, the differential pressure will be before and after the pressure control valve increases, the pressure control valve opens when is ice machine than the set pressure s, increased by the hot and cold source traffic to ensure safe operation of unit. Before and after the pressure control valve is open, you can always keep the valve pressure is almost constant. Flow through the valve and the flow of the user system showed the opposite change. Reduce the flow of the user system will increase the flow of the pressure control valve; user traffic increases, reducing the flow through the pressure control valve. This would ensure that the flow of hot and cold source will not be much change, both to protect the heat source, but also improves the stability of the unit operation.
The traditional way to protect the hot and cold source is the electric pressure control valve installed bypass pipe on the road. When the system flow decreases, the pressure is greater than before and after the electric valve set pressure, the signal-driven electric valve open, the cold and heat source unit to maintain the required oil spill response equipments . Electric pressure control valve due to the dependence of the line of the power supply and transmission of electrical signals, the reliability is better self-operated differential pressure control valve. In addition, the prices are higher than the latter. Therefore, in the protection of cold and heat source, can use self-operated self pressure control valve instead of the traditional electric control valve. Incidentally, the solenoid valve installed bypass pipe on the road as shown in Figure 2 is not appropriate, because the solenoid valve is only closed and fully open the two states, so it's every action, will be the user's system flows a greater impact.
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