APR-R7 Type Pressure Reducing Valve( For Steam)

General

This pressure reducing valve automatically adjusts the steam flow to meet the downsteam system demand, thus provides constant downsteam pressure.

The steam pressure reducing valve regulates the flow rate of the medium by controlling the opening and closing parts inside the valve body, thereby reducing the pressure of the medium. At the same time, adjust the opening of the opening and closing parts through the pressure behind the valve to maintain the pressure behind the valve at a certain level.Within this range, when the inlet pressure constantly changes, maintain the outlet pressure within the set range to protect subsequent household and production appliances. Steam pressure reducing valves are generally installed horizontally and controlled by the pressure behind the valve. When the pressure sensor detects an increase in the valve pressure indicator, the valve opening of the pressure reducing valve decreases; When the pressure of the pressure reducing valve is detected, the valve opening of the pressure reducing valve increases to meet the control requirements.

In steam energy-saving technology, high-pressure transportation and low-pressure use are the basic principles. Low pressure use can provide a larger proportion of steam latent heat, reduce the heat contained in the condensate, reduce the amount of secondary steam, and have higher dryness. There are many industries in China that use steam pressure reducing valves, but there are also many problems,leading damage to downstream steam equipment.

Some steam pressure reducing valves often have upstream pressure fluctuations or downstream load changes, making it difficult to achieve pressure control. When some steam pressure reducing valves are empty, downstream pressure continues to rise, causing overpressure.

We know that there are many structural types of steam pressure reducing valves.The commonly used steam pressure reducing valves in the past were diaphragm type and internal spring piston type.The pressure on the lower side of the metal diaphragm of the inner pilot piston pressure reducing valve causes the diaphragm to move up and close the main valve.The pressure on both sides of the piston gradually balances. When the downstream pressure is equal to the set pressure, the main valve finds its position. The position of the main valve has been determined. Adjust to set pressure. The normal position before starting the external pilot diaphragm steam pressure reducing valve is when the main valve is closed, and the pilot valve is opened by spring force. Steam enters the main diaphragm chamber through the pilot valve, and a portion of the steam flows out from the control hole.The control pressure in the main diaphragm chamber increases.When the main valve is opened, as steam flows through the main valve, the downstream pressure increases and is fed back to the lower part of the main diaphragm by the pressure sensing pipe (to ensure stable downstream pressure, the downstream pressure sensing pipe). This force balances the spring force on the upper part of the steam pressure reducing valve diaphragm, causing the pilot valve to gradually throttle and close, thereby maintaining the pressure in the main valve diaphragm chamber, controlling the opening of the main valve, delivering an appropriate amount of steam, and maintaining a stable downstream pressure.When the downstream pressure increases, the feedback pressure increases, the pilot valve closes, and the control pressure is released from the control hole, making the main valve tightly closed. Any downstream load changes or pressure fluctuations will be fed back to the lower part of the pilot valve diaphragm to adjust the opening of the main valve and ensure the stability of downstream pressure.

Although these two common steam pressure reducing valves may not be suitable for all working conditions, as long as we choose the pressure reducing valve based on the working conditions and flow rate, we can solve the problem of pressure reducing valves that can only reduce pressure and cannot be stable problem. It may have issues with upstream pressure fluctuations or downstream load changes, but when there is no load, downstream pressure continues to rise and overpressure occurs.

■ Working Principle

● Changes in downstream pressure are sensed by bellows, which expands or contracts depending on the pressure changes.

● The movement of the bellows will be directly transferred to the spring, whcih will open or close the main valve, thus keeping the downstream pressure at a certain level.