ASCO TD30A21 SA31DV Tri-Point Pressure Switch

ASCO TD30A21 SA31DV Tri-Point Pressure Switch is a two-piece ASCO pressure-control assembly that pairs the TD30A21 transducer with the SA31DV switch unit to deliver reliable pressure sensing and automatic electrical control in industrial systems. In ASCO’s S-Series, the transducer unit and switch unit are supplied as separate components that are ordered together by catalog number joined with a slash (for example TD30A21/SA31DV). The TD30A21 transducer part provides the pressure-sensing element and converts pressure into an electrical signal that drives the switch portion; the SA31DV switch unit contains a snap-action electrical contact that changes state when the sensed pressure reaches the setpoint. This Tri-Point configuration supports multiple switching actions from a single pressure input, enabling straightforward integration with control circuits for pumps, compressors, or processing equipment. Typical installations leverage ASCO’s two-component architecture to tailor setpoints and response characteristics for specific applications, while maintaining the robustness and repeatability typical of ASCO products. The combined TD30A21/SA31DV arrangement embodies the established ASCO two-piece approach that customers rely on for precise pressure monitoring and reliable circuit interlock or alarm signaling in industrial environments.