Pneumatic valve: Selection instructions for diaphragm pneumatic single seat regulating valve HPS-16C

Application positioning of pneumatic valve HPS-16C

The membrane type pneumatic single seat regulating valve HPS-16C is a pneumatic valve powered by compressed air, which can be used for continuous regulation of water, steam, general gases, and process media confirmed by material compatibility. The combination of a single seat valve core and a straight through valve body is suitable for pipelines with requirements for leakage and regulation stability. Actual selection should not be based solely on name or appearance, but should also provide maximum, normal, and minimum flow rates, as well as pressure, temperature, medium characteristics, and control signal requirements before and after the valve.

Structure and Working Principle

Valves typically consist of a multi spring diaphragm actuator, valve stem, valve cover, packing box, valve core, valve seat, and valve body. Control the air pressure acting on the membrane, pushing the valve stem to move in a straight line, changing the flow area between the valve core and the valve seat, and achieving process regulation of flow rate, pressure, or temperature. According to the process requirements during gas loss, the gas on or off form can be selected; When proportional control is required, valve positioners, filter pressure reducing valves, and feedback accessories can be configured.

Caliber, pressure and material

The nominal diameter can be selected according to series such as DN15 to DN200, and the final diameter should be calculated based on the flow coefficient and pressure difference. Common nominal pressures include PN16, PN25, and PN40, but the allowable pressure difference is also affected by the thrust of the actuator, the unbalanced force of the valve core, and the state of the medium. The valve body can be made of materials such as WCB, CF8, CF8M, etc; When facing corrosive media, the valve internals, packing, and sealing materials should be checked simultaneously. Soft seals help control leaks, while metal seals can adapt to some higher temperature conditions, and should be based on actual medium conditions.

Driving characteristics and applicable industries

The thin film pneumatic drive has a stable response and is easy to connect to the pneumatic control circuit. The single seat structure is suitable for regulating small to medium flow rates, but it requires verification of cavitation, flash evaporation, noise, and valve core stress under large pressure differentials. This type of pneumatic valve can be used in chemical batching, water treatment, HVAC heat exchange, pharmaceutical auxiliary systems, food utilities, papermaking, and general industrial processes. For conditions involving flammable, explosive, high-temperature, or toxic media, corresponding safety and protective accessories should be added according to site specifications.

Installation and maintenance

Before installation, the pipeline welding slag and debris should be cleaned, and a filter should be installed in front of the valve if necessary. The flow direction of the valve body should be consistent with the requirements of the nameplate or arrow, and space should be reserved for the disassembly and assembly of the actuator. During debugging, first check the cleanliness and supply pressure of the gas source, and then verify the stroke, zero point of the locator, and full range. If there are adjustment fluctuations, external leaks, or insufficient travel during operation, check the air source, locator, packing tightness, valve stem action, and wear of valve internals in sequence. Before maintenance, the medium must be isolated and pressure released according to on-site regulations.

Q&A on Pneumatic Valve Selection

Q: Is DN50 necessarily suitable for 50 millimeter pipes?Answer: Not necessarily, the valve diameter should be determined by the flow coefficient, pressure difference, and adjustable ratio.Question: Is the air on or off?Answer: The selection should be based on the process safety state of wanting the valve to be in the open or closed position when gas is lost.Q: When do I need a locator?Answer: When continuous proportional adjustment, remote feedback, or overcoming friction effects are required, it is usually recommended to configure.Question: How is the material determined?Answer: It should be confirmed comprehensively based on the corrosiveness of the medium, temperature, pressure, particle condition, and cleaning requirements.

Usage conditions and supporting suggestions

To ensure that the regulating valve operates near the design conditions, it is recommended to list the medium density, viscosity, saturated vapor pressure, and whether it contains solid particles in the selection table. Drainage, insulation, and post valve condensation should also be considered for steam pipelines; Attention should be paid to water hammer, impurities, and winter antifreeze in the water system. Necessary pressure measuring points should be set up before and after the control valve to facilitate the determination of whether the pressure difference changes beyond the calculation conditions. The air source system should use dry and clean instrument air, and the filter pressure reducing valve should be easy to inspect. If there is a rapid response or signal fluctuation in the control circuit, the process and control personnel should jointly adjust the locator parameters and controller settings, rather than simply increasing the gas supply pressure.

Before delivery, the connection standard, flange sealing surface, bolt grade, actuator action direction, and nameplate parameters can be checked. On site inspection should include visual, travel, feedback signal, and low-voltage action checks; After running under pressure, observe whether there is any leakage at the connection between the packing box and the flange. Fouten Flow Control (Jiangsu) Co., Ltd. recommends that users keep complete operating condition records for traceability during subsequent maintenance, spare parts selection, and system modifications.