Retraction mechanism for valve insertable sensors

摘要

A retraction mechanism permits easily removing a sensor assembly from a pressurized process fluid container through a valve attached to an opening in the container. The retraction mechanism includes a folding support linkage having a first end and a second end formed from at least two links that are joined together to have a pivot joint located therebetween. The first end of the support linkage is joined to the sensor assembly, while the second end of the support linkage is joined to the valve or the fluid container. The two links are partially folded when the sensor assembly is in operable position, and pivot about the pivot joint to unfold when the sensor assembly is removed. The retraction mechanism further includes a damper connected between the two links of the support linkage. The damper provides a damping or restraining force for the sensor assembly as the sensor assembly is removed from the fluid container.