How a Pneumatic Temperature Controller Works

AMOT Model G 3-way rotary control valves provide a high degree of accuracy for precise temperature control in both mixing and diverting applications. Reducing the amount of lift or limiting a valve’s travel is sometimes required in a control system for performance or safety reasons. Valves are sometimes mistakenly oversized resulting in inefficient operation at the lower 5-10% of their travel. Similar to split-ranging the input signal to match the full stroke of the valve as described in the previous section, the positioner’s pneumatic output signal can be compressed to match the full electrical signal input. This allows full input resolution of the control signal to be applied to the first 5-10% of the valve stroke.
Expect to receive quality products with the added benefit of local representation and shorter lead times. Modern thermostats and controllers are generally resistant to this calibration drift, it is good practice nevertheless to maintain constant main air whenever possible. On a site with many buildings, a letter code will usually be included before the system, e.g. AI DUF AH1 OAT. If buildings are on multiple sites, the coding may have a site code and then a building code. The critical issue is to be clear and consistent about your system.
SMC mechanical valves have been designed to meet general industry standards and are capable of long, trouble-free life under stringent operating conditions. The simple construction, utilizing corrosion resistant aluminum die cast bodies with optional heavy duty actuators and Buna N seal design, ensure positive operation and media control. SMC offers Direct Operated Solenoid Valve in 3 port, 4 port, 5 port and suitable for vacuum and copper free application.
Zone Valves – Very popular valves for low pressure control of fan-coil units, radiators and small zones. Zone valves are typically available in sizes from ½” to 1½”, with flared, sweat or threaded connections. Zone valves’ compact size makes them a popular choice in tight situations.
Temperature Control valves are actuated control valves and are available on the market with or without added dynamic flow control. Both types are common in heating as well as cooling applications and assist in the aim of accurate temperature control. Choice of actuator can be either thermal or electrical depending on the application and one’s budget.
The software helps the end-user interactively set-up, tune and maintain the control valve / positioner and save the configuration into a software file for later reference or download. Automation is typically done with rotary actuators for the butterfly, plug and ball valves. van điều khiển điện , light-weight control valves for mixing in low flow process applications and three way control valves for mixing or diverting services.
“Air or current to open” – The flow restriction decreases with increased control signal value. Valve actuator – which moves the valve’s modulating element, such as ball or butterfly. When flow reduces, the temperature comes down and the valve achieves a new position. Choose between different actuator, setup and sensor variants and the right communication interface specifically for your application.Contact us with your individual needsand we’ll find the ideal variant for your system.
Control valves come in a wide assortment of shapes and sizes, and can be controlled in many ways. NECC stocks valve actuators and linkages separately that can be used to put together over 30,000 combinations of different valve assemblies. Here are some descriptions to help narrow your search, and help you find exactly what you need.

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