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1. Characteristics of rotary valves: Valves are generally divided into two main categories: linear stroke type and rotary type. A straight-stroke valve allows or stops the flow of material through a component that moves in a straight line, such as a gate. Straight-stroke valves include globe valves, gate valves, diaphragm valves, etc. A rotary valve allows or blocks the flow of material through a rotating component. A rotary valve in which the rotating component can turn 90 degrees is called a 1/4 rotary valve. Sometimes, the classification of 1/4 rotary valves can be extended to rotary valves with an angle of less than 270 degrees. As defined, a rotary valve is a type of valve that changes from an open position to a closed position by rotating a rotating component such as a swing gate through 90 degrees. Rotary valves generally have the following characteristics. (1) Wide adjustment range: In the process industry, the adjustment range is of utmost importance. The adjustment range of rotary valves is approximately 150:1 (the adjustment range of VALTEK’s ball valves can reach 300:1, while that of butterfly valves and cam-flexible valves is 100:1). The adjustable range of the corresponding stop valve is 30:1; in other words, the rotary valve offers a 5 times wider adjustable range. For example, when the maximum flow rate is 1000 liters per minute, a globe valve can effectively reduce the flow rate to 30 liters per minute, while a rotary valve can adjust the flow rate to below 10 liters per minute. The more precisely the flow rate can be controlled by these valves, the better the repeatability in the process, which directly reduces the number of defective products in process industries. Two features of the eccentric rotary valve enhance its range of adjustability. The first is its orifice-style design: the eccentricity takes the form of an effective 1/4 circle, and the valve core is V-shaped, whereas traditional valve cores are circular. When the eccentric rotary valve is closed, its small V-shaped shape enables very precise control at low flow rates; at high flow rates, it almost opens the valve to a size equivalent to the diameter of the pipe. The second feature is that the actuators of the stroke rotary valves in the actuating machines come in two types: diaphragm type with a certain stroke and cylinder type. The stroke of a 1” globe valve is approximately 3/4” to 7/8”, while that of a rotary valve exceeds 2”. For valves of any other size. The greater the travel at the input side, the better the control at the output side. Control valves with high adjustability enable precise proportioning as required by the formula, regardless of the flow rates in various channels; traditional linear or control valves are no longer suitable for such tasks. Rotary valves can improve the performance of the system while reducing the costs associated with control valves over the device’s operational life cycle. Rotary valves with a wide adjustment range allow users to raise the standards for tight shutdown, thereby improving cost/benefit ratios. A metal valve seat, combined with components made from special materials, can extend the service life of the valve and improve its performance. The design of a simple rotating structure can minimize maintenance efforts. Reduce the owners’ production costs. (2) Tight sealing: The shaft of a straight-stroke valve is used for the valve stem to move in and out of the valve body, and product is carried out with each cycle. It is difficult to prevent leakage in a straight-stroke design, as this can allow unwanted products to enter the production system and result in significant, unacceptable volatile leaks within the factory. The rotary design of rotary valves essentially does not have this problem, as such valves utilize cylinder-type actuators with low hysteresis and high thrust, which offer greater precision and stability compared to other types of actuators; they also feature metal valve seats that enable long-term, tight sealing. (3) Large flow capacity and small size: The flow capacity of a straight-stroke valve is a fraction of the flow capacity of the pipeline in which it is installed. To increase the flow capacity, the size of the straight-stroke valve is increased; it is often larger than the pipeline itself. The capacity of a rotary valve is approximately 2 to 3 times that of a straight-stroke valve of the same size. Rotary valves can be used to increase the mixing ratio without having to change the size of the feed lines, which helps to significantly reduce costs. For this reason, some rotary valves have been designed with a flange-to-flange connection style that can replace gate valves, and they are equipped with connecting bolts; such valves are even cheaper than the gate valves they replace. (4) Cavitation resistance: In process industries, throttling can lead to significant cavitation, which may damage pipes, generate unacceptable levels of noise, and also disrupt measurement systems, resulting in inaccurate or unreliable readings. Rotary valves feature a robust design that reduces the risk of valve failure due to water hammer effects; moreover, their valve cores can absorb some of the excess energy, thereby significantly reducing cavitation and related problems. (5) No external leakage: Standard rotary valves have a leakage rate 100 times better than that of standard globe valves; the movement of the valve stem in globe valves draws in dust and sand, which damages the graphite packing. In a rotary valve, the valve stem does not move in and out but rather rotates, thereby avoiding damage to the packing and preventing external leakage.