Insertion Probe Information from Swagelok  (click on the title to view the complete Information)

The following information is intended to provide guidance to define process interface valves with injection or sampling insertion probes (also referred to as quills).

Insertion probes are typically used for one of two functions:
Injection – where fluid flows through the probe directly into the process line. Sampling – where fluid is extracted from the process line through the probe.

Consideration should be taken to ensure that the insertion probe will not fail in service due to the effects of resonance. The velocity of the process fluid flowing over the probe can induce vibration in the probe which may cause the probe to fail.
One method for determining that the probe natural frequency is sufficiently greater than that caused by the fluid flow rate is defined in the EEMUA (Engineering Equipment & Materials Users' Association), Publication 138:1988, Design and Installation of On-Line Analyser Systems, Appendix 2.