Multi-function pump control valve working principle

The new multi-function water Pump Control Valve installed on the outlet pipe of the centrifugal pump has three functions of gate valve, check valve and water hammer canceller. This paper introduces the construction, performance parameters, working principle, device debugging and precautions of the multi-function water pump control valve.

First, the function requirements of the multi-function pump control valve are usually used to ensure the normal operation of the pump. The centrifugal pump is a commonly used pump in the water supply and drainage project. The water outlet pipe of the water pump is equipped with three kinds of valve members: a gate valve, a check valve and a water hammer canceler. These three valve members play different roles in the operation of the water pump: the gate valve is normally closed. When the pump starts, the gate valve opens slowly. When the pump stops, the gate valve closes slowly. The closing and closing of the pump can effectively prevent the pump water hammer and the pump water hammer from being stopped. At the same time, the motor load when the pump starts is reduced. The shaft power of the pump at zero flow is small, generally only designed. 30% of shaft power. Another function of the gate valve is to provide safe maintenance conditions for the valve and pump installed in the check valve between the gate valve and the water pump when the gate valve is closed, to prevent the water from flowing back. The check valve can prevent sudden power failure. When the flow of water caused by the change of flow, to prevent backflow; but the sudden closing of the check valve is prone to water hammer phenomenon. When the geometric pumping height of the pump is large, the severe high pressure of the water hammer will cause the pipeline to rupture and cause serious production accidents. To prevent water hammer from damaging the water pipeline, a water hammer eliminator is often installed on the water pressure pipe of the water pump. In order to realize the automation of pump operation, simplify management, reduce labor and improve reliability, people replace the manual valve with Hydraulic Valve and electric valve, and carry out a number of technical improvements on the single valve, showing the slow opening and closing check valve and easing. Open and close hydraulic VALVES, automatic slow-closing gate valves, two-speed self-closing valves and other new valves.

However, it is still unsatisfactory, and the above measures have achieved certain effects in application practice. The use of pressure sensing and electric drive control has many complex faults, and the improvement of a single valve cannot solve the main problem of automatic operation. Therefore, people have been working on the development of a valve with the function of three kinds of valve components, such as gate valve, check valve and water hammer eliminator, which can reduce the land occupation while meeting the above comprehensive requirements. JD745X multi-function water pump control valve is one of the better ones. It has the advantages of one valve multi-function, reliable operation, simplified operation, easy maintenance, and automatic operation according to the operation requirements of the pump. It is very popular among users.

The operating pressure is greater than or equal to O.1MPa medium temperature is 080 °C, the slow closing time can be adjusted within 3-90, the pressure loss when the pipeline flow rate is 2ms is less than 0.01MPa, the working pressure of the multi-function water pump control valve is 1. 0MPa and 1.6MPa2.5MPa three. Working pressure of water hammer peak less than 1.5 times, nominal diameter DN50-DNl0000

Second, the basic structure consists of the main valve and the external accessories. Among them, the overall size of the valve is equivalent to the ordinary check valve. The main valve includes a valve body, a pressure plate and a diaphragm, a large valve plate, a slow closing valve plate, a valve seat, a valve stem assembly and the like. The valve stem assembly of the slow-closing valve plate is connected with the pressure plate and the diaphragm, and the diaphragm is pressed between the valve cover and the diaphragm seat, and the up and down movement of the diaphragm drives the slow-closing valve to rise and fall. The valve stem passes through the center hole of the large valve plate, so that the large valve plate can slide along the valve stem within a certain range. In normal times, the large valve plate is pressed against the valve seat under the pressure of its own weight and the upper compression spring, so that the valve is closed. The external accessory of the multi-function water pump control valve is installed on both sides of the valve diaphragm and the inlet and outlet pipes of the valve. The control valve, the filter and a special counter-stop are installed on the connecting pipe of the lower chamber of the diaphragm and the inlet side of the valve. valve. There is only a filter and a control valve on the connecting pipe of the upper chamber of the diaphragm and the water outlet side of the valve. The movement and position of the large valve plate and the slow-closing valve plate in the main valve determine the change of the working state of the valve and the opening and closing. The external fittings and pipelines of the valve transmit the pressure changes before and after the valve to the upper and lower chambers separated by the diaphragm, control the movement of the large valve plate and the slow-closing valve plate, and can change the large valve plate by adjusting the accessories. Slowly closing the operating speed of the valve plate, so that the opening and closing time of the valve is within the specified range.

III. Working principle The multi-function water pump control valve is automatically operated when the pump is started-closed. The working principle is discussed separately: the pump-stop valve plate is completely closed under the static pressure of the inlet end and the diaphragm upper chamber.