Vane or paddle flow switches are used to initiate high or low flow alarms. A common application is as a low flow alarm for shut-down of a system for protection of the components from damage. Often these are used in cooling lines, oil lines, or monitoring other fluid flows that are critical for the system to operate. Continue reading “Custom Vanes for the V4 Vane Operated Flow Switch”
RTD Temperature Sensors
Dwyer Instruments, Inc. offers a wide variety of temperature sensors that use RTDs as the sensing element.
RTDs are based on the principal that the electrical resistance of the wire is a function of the temperature, with the resistance increasing as temperature increases. The resistance varies nearly linearly with temperature per the Callendar Van-Dusen equation. The wire used in RTDs as the sensing element is usually constructed of platinum, copper, or nickel. Platinum is the best material for this element, as it has the widest useful temperature range of these materials. It also has a very repeatable and linear temperature to resistance correlation. Continue reading “RTD Temperature Sensors”
U.S. and International Threaded Connection Standards
Threaded connections are often referred to as a process connection type. For Dwyer product specifications, this connection type is typically NPT (National Pipe Thread), which is an American standard thread. These connections allow products to be installed directly into piping or with the use of threaded fittings.
For threaded connections there are two common types, (1.) straight or parallel thread and (2.) tapered thread. Continue reading “U.S. and International Threaded Connection Standards”
Control Valve Sizing
Control valves are used to change process conditions such as flow, temperature, level, and pH. A complete control system would include a sensor, controller, positioner or current to pressure transducer, and control valve. Globe valves, such as the Dwyer Hi-Flow™ Series, are a common type of control valve. In the example shown, a Hi-Flow™ control valve is controlling temperature by varying the amount of steam or cold water added to the process. Continue reading “Control Valve Sizing”
Ask the Expert – Series 626 & 628 Pressure Transmitters Offer Optional NSF Approval
Question: I have been searching for a pressure transmitter with an NSF 61 certification for my drinking water application. Does Dwyer have any recommendations? Continue reading “Ask the Expert – Series 626 & 628 Pressure Transmitters Offer Optional NSF Approval”