PZII-2000 Mining Flameproof Electric Water Distribution Gate Valve
$12600
Category: Machinery & Equipment/Engineering & Construction Machinery/Other Engineering & Construction Machinery
Company: 济宁展翔工程机械有限公司
Product Description: Jining Zhanxiang specializes in the production of various models of water distribution gate valves, ensuring quality, competitive prices, reliable after-sales service, and bulk order discounts. Water distribution gate valves are worth having.PZ1 water distribution gate valve, water distribution gate valve, PZ1 water distribution gate valve, PZI type water distribution gate valve, water distribution gate valve price, water distribution gate valve manufacturer.The opening and closing component of a gate valve is the gate, which moves perpendicular to the fluid flow direction. Gate valves can only be fully opened or fully closed and cannot be used for regulation or throttling. The gate has two sealing surfaces. The most common type of gate valve features two sealing surfaces forming a wedge shape, with the wedge angle varying depending on valve parameters, typically 50 degrees, or 2°52' when the medium temperature is not high. The wedge gate can be made as a single solid piece, known as a rigid gate, or as a flexible gate capable of slight deformation to improve manufacturability and compensate for deviations in the sealing surface angle during processing. When a gate valve is closed, the sealing surfaces can rely solely on medium pressure for sealing, meaning the medium pressure presses the gate's sealing surfaces against the valve seat on the opposite side to ensure a tight seal—this is known as self-sealing. Most gate valves use forced sealing, meaning that when the valve is closed, external force is required to press the gate against the valve seat to ensure sealing integrity. In gate valves where the gate moves linearly with the valve stem, it is called a rising stem gate valve or an outside screw and yoke (OS&Y) gate valve. Typically, the rising stem has trapezoidal threading, and the rotational motion is converted into linear motion via a nut at the top of the valve and guide grooves in the valve body, transforming operational torque into thrust. When the valve is opened, and the gate is raised to a height equal to 1:1 times the valve's nominal diameter, the fluid passage is fully unobstructed. However, this position cannot be monitored during operation. In practice, the valve's fully open position is determined by the top position of the valve stem, where it can no longer move. To prevent locking due to temperature changes, the valve is usually turned back 1/2 to 1 turn from the fully open position. Thus, the fully open position of the valve is determined by the gate's position or travel. Some gate valves have the valve stem nut set on the gate itself; rotating the handwheel turns the valve stem, lifting the gate. This type is called a non-rising stem gate valve or an inside screw gate valve.Advantages of gate valves include:1. Low flow resistance. The internal medium passage of the valve body is straight, allowing linear flow with minimal resistance.2. Easy opening and closing. Compared to globe valves, less effort is required because the gate moves perpendicular to the flow direction whether opening or closing.3. Large height and long opening/closing time. The gate has a significant travel distance and is lowered via a screw mechanism.4. Minimal water hammer effect. This is due to the slow closing process.5. Bidirectional flow capability, easy installation. The valve passage is symmetrical on both sides.6. Short structural length (the distance between the two connecting ends of the valve body).7. Prone to sealing surface wear, affecting service life. During operation, the gate and valve seat sealing surfaces rub against each other, leading to scratches and wear under medium pressure, compromising sealing performance and reducing lifespan.8. Higher cost. Multiple sealing surfaces require complex machining, particularly the valve seat sealing surfaces, and the valve has more components. Simple shape, short structural length, good manufacturability, and wide applicability.Disadvantages of gate valves include:1. Sealing surfaces are susceptible to erosion and wear, making maintenance difficult.2. Large overall dimensions, requiring significant space for operation, and long opening/closing times.3. Relatively complex structure.Gate Valve Installation and Maintenance:1. Do not use the handwheel, handle, or transmission mechanism for lifting, and avoid impact.2. Double gate valves should be installed vertically (with the valve stem in a vertical position and the handwheel at the top).3. For gate valves with a bypass valve, open the bypass valve first before opening the main valve (to balance the pressure difference between inlet and outlet and reduce opening force).4. Install gate valves with transmission mechanisms according to the product manual instructions.5. If the valve is frequently operated, lubricate it at least once a month.6. Gate valves are used for shutting off media flow. When fully open, the flow passage is straight, resulting in minimal pressure loss.7. Gate valves are typically suitable for applications where frequent operation is not required, and the valve is kept fully open or closed.8. Gate valves are not suitable for regulation or throttling. For high-velocity media, partially opening the gate can cause vibration, potentially damaging the gate and seat sealing surfaces, and throttling can lead to erosion of the gate by the medium.
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