Chemical hose applications require extra consideration where higher temperatures are present. A hose may list a temperature range on the spec sheet, but that is only part of the equation. For example, Continental Chemone shows a max temperature rating for the hose as 250F. The manufacturer has determined that the hose can operate at that temperature without damage. An assembly, with couplings installed, is a different situation. With fittings crimped in place, the allowable working pressure for the assembly at 250F would drop to 13.5PSI, vs the 200 PSI rating at ambient temperature.
The reason for this is that coupling retention becomes more of an issue as temperature increases. See the Elevated temperature pressure derating chart below for more information.
How the De-rating chart works: The chart lists temperatures across the top and hose type down the left column. Based on your hose system application, locate the appropriate de-rating factor and multiply it by the hose system pressure rating in the pressure chart above.
Fortunately, there are a number of safe options for chemical transfer at elevated temperatures, including PTFE lined hose and flexible all metallic hoses. In many cases higher temp range operations benefit from a stronger coupling design, like flanges or Campbell’s Chemjoint fittings. We have the experience needed to help design a hose assembly for higher temperature service.