| Applies when | freon, refrigerant, hydrocarbon, fuel, diesel, gasoline, crude oil, creosote, tall oil |
|---|---|
| Avoid | magmeter, magnetic flow meter (Instrumentation) |
| Recommend instead | clamp-on ultrasonic flow meter (zero wetted parts) or a fluoropolymer in-line ultrasonic meter, not a magmeter (Instrumentation) |
| Rationale | Two distinct findings from reading the Flowline chart against this project's own instrumentation corpus. First, across all six refrigerants in the chart (Freon-11, -12, -21, -22, -113, -114) PVDF, PFA, and PTFE all rate Excellent while 316 stainless steel drops to Fair - the only place in the 552-row table where stainless is the weakest listed wetted material against an otherwise benign-looking fluid (a milder version of the same pattern appears on creosote/tall oil and hot olive oil). Second, GF Signet's own 2551 and 2552 magmeter datasheets state a minimum fluid conductivity of 20 microsiemens/cm, which hydrocarbons and refrigerants do not meet - meaning most of this project's captured flow-instrumentation catalog is physically inapplicable to this chemical family regardless of wetted-material choice. Both findings invert the intuitive assumption ('stainless is the safe default,' 'a magmeter is the accurate flow-measurement choice'), so both must be stated explicitly rather than assumed away. |
| Confidence | confirmed |
| Source | data/reference/nuance-appendix.md (nuance 2), data/reference/flowline-chemical-compatibility.csv, data/vendor-sources/gf-signet-instrumentation-catalog.md, data/vendor-sources/icon-process-controls-flow-meters.md |
This is a general engineering rule derived from real field/case-study evidence, not a substitute for a project-specific specification review — confirm against your exact process conditions before ordering equipment.
Reviewed by James Riggins, Founder, LibertyCES — 30+ years specifying industrial fluid-handling equipment for the exact failure modes this rule addresses. Request a free spec review →
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freon, refrigerant, hydrocarbon, fuel, diesel, gasoline, crude oil, creosote, tall oil
Two distinct findings from reading the Flowline chart against this project's own instrumentation corpus. First, across all six refrigerants in the chart (Freon-11, -12, -21, -22, -113, -114) PVDF, PFA, and PTFE all rate Excellent while 316 stainless steel drops to Fair - the only place in the 552-row table where stainless is the weakest listed wetted material against an otherwise benign-looking fluid (a milder version of the same pattern appears on creosote/tall oil and hot olive oil). Second, GF Signet's own 2551 and 2552 magmeter datasheets state a minimum fluid conductivity of 20 microsiemens/cm, which hydrocarbons and refrigerants do not meet - meaning most of this project's captured flow-instrumentation catalog is physically inapplicable to this chemical family regardless of wetted-material choice. Both findings invert the intuitive assumption ('stainless is the safe default,' 'a magmeter is the accurate flow-measurement choice'), so both must be stated explicitly rather than assumed away.
clamp-on ultrasonic flow meter (zero wetted parts) or a fluoropolymer in-line ultrasonic meter, not a magmeter (Instrumentation)
Source: Liberty Chemical Equipment & Supply, Inc. (LibertyCES) — engineering data compiled and reviewed by James Riggins, Founder, LibertyCES, from real vendor and field-verified sources. For a free spec review, call James at (559) 395-5500 or email [email protected] / [email protected]. Website: libertyces.com.