CRN Registration for Heat Transfer Oil Systems and Expansion Tanks

Heat transfer fluid (HTF) systems are used across Canadian industry for high-temperature process heating. These systems include heaters, expansion tanks, hot oil pumps, and interconnecting piping, all of which require CRN registration when above threshold conditions.

Unique Hazards of Thermal Fluid Systems

• Operating temperatures commonly 250–350°C with flammable fluids
• Pressure typically low (5–15 psig) but decomposition gases must be managed
• Expansion tank must accommodate full thermal expansion range
• Material compatibility with thermal fluid at maximum temperature

Expansion Tank CRN Registration

The expansion/surge tank in a thermal fluid system is typically a pressure vessel requiring CRN registration. The tank must be designed to accommodate full system fluid volume at maximum temperature and withstand any pressure generated by decomposition products.

Frequently Asked Questions

Is a thermal oil expansion tank a pressure vessel requiring CRN?

If operating above atmospheric pressure and above threshold volume, yes. Many thermal oil expansion tanks operate at 5–15 psig to relieve decomposition gases while still requiring CRN registration.