Low Volume Flow Switch - KSR/SVN

Control of Very Small Liquid or Gas Flows

Models KSR and SVN micro flow switches are designed to provide switching capacities for low flow ranges for either water or air. The water range is from 0.03 to 4 GPH and the air range is from 0.1…13 SCFH. They feature vertical connections for inline mounting and are for vertical, flow upward use. The switching value is determined and specified by the customer and set by the factory.

Principle of Operation

KOBOLD KSR and SVN flow switches operate on a simple principle. If the flow rate reaches the user specified switch-point, the flow raises or drops the internal float to the stopping point. The KSR switching function operates via a reed contact which can be either SPST or SPDT. The SVN switching function operates via an inductive proximity switch which transmits the signal to a suitable power supply or relay module.


Models KSR and SVN come standard in ¼” NPT and feature a maximum pressure of 230 PSIG and a maximum temperature of 160 °F. The non-wetted housing is made of anodized aluminum and the wetted parts are 303 stainless steel, FKM, and borosilicate glass.