Paraffinic Hydrocarbons

Er, what about using water for hydrostatic testing? Safe, cheap, non-flammable, and compatible with the local environment when the test fails and the equipment leaks.

I'd thought of that. Only, we also test older components that have a residual about of hyd. or fuel oil that ends up in the test stand tank which eventually creates a nasty sludge. The solvent we use is an environmentally prefered solvent and the aim is to use that solvent to clean and test thus eliminate the other hazardous test fluids that have been mandated for us to use.

Welcome to CR4 Superchemist! I was about to answer the question, but you beat me to it. Glad to see more chemists around here (my background is physical-organic, I earned by M.S. from the University of Florida).

Thank for the data Superchemist, it will be helpful in my argument with my local engineer.

As long as the chains have more than 7 carbons, they should be fine for hydro testing. As stated before, iso means a branched version of a straight linked chains we call parafins.

The use of flable fluids in tests is allowed as long as you have a plan in place to handle a failure of the tested device.

Thanks for the additional data Vicini, this and the data from Superchemist will be helpful in my argument with my local engineer who argues that solvents that are paraffin based are not a suitable test medium, He goes on about system contamination, fluid flow and friction which isn't a factor in single piece testing of a low to high pressure hose or tube. All that is being tested is proof and burst pressures.