Automatic Recirculation Valve

On November 14, 2019, the famous Japanese valve manufacturer sawamura Valve Co., Ltd. and its president, Mr. Naoki sawamura, came to our company for inspection. Mr. Yu Chengshan, chairman of the company, warmly welcomed the arrival of Naoki sawamura, accompanied Naoki sawamura to conduct a comprehensive inspection and understanding of the company’s production base, and then conducted in-depth exchanges on technology and business. Since its establishment in 1925, SAWAMURA Co., Ltd. has been providing products for ships, power plants, petrochemical plants, etc. The main customers of the company include Mitsubishi Heavy Industries, Tokyo Electric Power, Toshiba Corporation, Kawasaki Heavy Industries, Nisshin Steel, Nippon steel corporation, Miho shipyard, Nakatani shipbuilding and other fields. Adhering to the business philosophy of “Just try it”, Sawamura valve has developed and improved a variety of valves in a variety of applications to meet customers’ needs for safety, durability, performance and cost effectiveness. Through centuries of accumulated experience, the product has established a very strong “Japanese quality” manufacturing standard in the market. With the globalization of the market, Sawamura valve will also expand its supply and purchase network …

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Centrifugal pumps rely on fluid to keep cool and lubricated while operating. They also rely on the fact that discharged fluid has somewhere to go. But what if the process dictates it needs only a fraction of the pump’s minimum flow requirement? What if there’s a closed valve downstream? What happens when a pump’s basic hydraulic needs are no longer met? This is where a minimum flow bypass line is best applied. A bypass line is most commonly used when there’s an issue meeting the minimum flow requirements, and/or for protection against deadheading the pump. A minimum flow bypass, or recirculation, line can be configured many ways. It could be as simple as a continuous bypass, where the requirements are only piping and an orifice. A more complex line could be set up to use a series of valves. Below is an illustration of a simple minimum flow bypass line. MEETING MINIMUM FLOW CONDITIONS Every pump has a minimum flow requirement. Operating pumps at below minimum flow can result in the following consequences: Pitted/worn impeller vanes Overheated casing/bearings Excessive noise …

What Is A Centrifugal Pump Minimum Flow Bypass Line? Read More »

Normally pump protection valves are limited to minimum flow protection; however, severe damage can occur to the pump and driver by exceeding the intended operating range of the pump. Damage due to excessive flow can be eliminated by designing a “Maxi-Flow” as an addition to the standard minimum flow valve. Excessive flow protection is achieved by installing an insert with a row of orifice holes into the main valve body. During normal main flow operation, the fluid passes through the holes with a minimal pressure head loss. In addition, a special disc is provided which has a sleeve around the diameter with a row of orifice holes. The disc is at full lift when the forward flow reaches the maximum desired flow rate. At the full lift, the orifice holes in the body insert and disc line up stopping the additional flow. Maximum flow protection prevents exceeding the steam drum desired water level if the drum level control valve failed open in boiler feed service. For process fluids and seawater in which pipe corrosion is a concern, the maximum flow protection provides run …

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Automatic recirculation valves Before start-up all lines must be flushed and the medium must be free from solids. Our valves are not designed to handle these. The lifetime of the valves will be strongly reduced due to increased wear when the fluid handled contains solids. If the lines are not clean they can be flushed with the valves installed. This should, however, be done with the valve internals removed and at reduced pressures. Note that with the removal of the internals the non-return- and pressure letdown function are no longer present. After flushing, the internals shall be reinstalled again. If the medium contains solids in the normal process we advise you to install a strainer with a mesh aperture of 0,25 to 0,5 mm in front of the pump inlet because solids could block the movement of the valve internals. Once the system is clean and filled with liquid the actual start-up can take place. The bypass line must have a guaranteed free flow path. This line should preferably not contain any valves except a non-return valve. If a gate- …

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The DATIAN automatic recirculation valves are best installed directly on the outlet of the pumps for which they are meant. The valve layout is mainly based on the pump curve. Ensure that the valves are installed on the right pumps. The flow direction is indicated on the valve nameplate. This nameplate is riveted to the valve body. On this nameplate, you will also find the valve’s commissioning- or fabrication number. This number is unique and therefore different for each valve. This ensures that the valves can always be related to the right pump. In case of spare parts requirements always refer to this number. As a standard, the valves are supplied as a complete unit and can be installed directly after receipt. Normally the connections are flanged but upon request, we can also supply the valves with butt weld ends. The packing is required between the valves and the piping is not part of our scope of supply. These packing can be supplied as an option. This is also the case with the bolts and nuts. Depending on the weight of …

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Avoid resonance with the system. When used with a pulsation damper, the pulsation damper should be placed between the pump and the backpressure valve to absorb the peak flow between the pump and the backpressure valve. Slow down the wear rate of the backpressure valve. For outdoor use, a protective shed or a protective cover should be added. Before performing any maintenance on the backpressure valve, stop the equipment, relieve pressure, close the valve that the backpressure valve is connected to the system, and verify that there is no pressure in the pulsation damper. Take care to prevent the liquid from being transported from harming the human body during maintenance. If the inlet and outlet of the backpressure valve are reversed, the back pressure will be multiplied, which will bring harm to the system and may be dangerous. Valve imported pump industrial washing machine If the backpressure valve fails during operation, the power should be cut off in time. Note: Before performing any maintenance on the back pressure valve, stop the equipment, relieve pressure, close the valve that the backpressure …

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The automatic recirculation valve is mainly installed at the outlet of the centrifugal pump. When the centrifugal pump outlet flow is lower than the minimum flow, the pump protection valve is bypassed, and the minimum flow of the pump design is bypassed to the pump suction device to avoid centrifugation. The pump is damaged due to overheating. PERFORMANCE ADVANTAGES OF AUTOMATIC RECIRCULATION VALVES The automatic recirculation valve (ARC valve) is a fully mechanical structure that controls the valve by the flow and pressure of the medium and does not require additional energy. The automatic recirculation valve (ARC valve) only recirculates when the flow rate is low so that the pump is cooled, and there is no recirculation when the pump is in normal operation, thereby saving the electric energy and water energy consumed by continuous recirculation. The automatic recirculation valve (ARC valve) does not require electrical wiring or two series of regulating valves. Unlike conventional control valves, we only need one valve for pump protection, eliminating the need for actuators, flow meters, and control units. The automatic recirculation valve (ARC valve) …

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There are many types of auto-reflux valves. The 3-way auto-reflux valve we have today has three ports, one in and two out, (left in, right and bottom). Unlike ordinary valves, there is an outlet at the bottom, when the internal spool is in different positions. When the outlet is different, for example, when the spool is at the lower part, the left and right sides communicate. If the spool is at the upper part, the right outlet is blocked, and the left and lower ports are open. Because the left and right mouths are not on a horizontal line. When the emergency is disengaged, the valve is closed and the water is bypassed. The 3-way auto-reflux valve, A valve that protects the system from damage due to excessive pressure. Once the pressure of the medium in the system piping or device exceeds the set value, the pressure is automatically released to achieve safety protection. The return valve has two types: spring type and rod type. There are also impulse safety valves, pilot safety valves, safety switching valves, safety decompression valves, static and heavy …

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