Typically, the thickness is usually selected based on the temperature of the piping and the minimum ambient temperature and to a lessor extent, the type of insulation used from a company's specifications.
Note: this program is for fiberglass & mineral wool type insulation due to its sponsoring manufacturers. If you don't have high temperature requirements, foam insulations have lower conductivity and are less likely to have problem with condensation than open or porous materials such as fiberglass & mineral wool. Although, not fire-resistant.
For insulating chilled lines, styrofoam type is best.
If you only need to go up to 300 F, I think polyisocyanurate is best. I have no connection with Dow, but have used their Trymer rigd foam insulation in a metal finishing plant: "Trymer polyisocyanurate pipe insulation, a CFC-free, polyurethane-modified polyisocyanurate rigid foam insulation, offers a temperature range from —297°F to 300°F, excellent chemical and solvent resistance, and excellent resistance to both moisture and damage."
In our plant we use minimum thickness of 0.25 mm for austenitic stainless steel jacketing material. If we use alumimum sheet, the thickness will be increased.
Taken as a minimum requirement, 0.25 mm thickness should be o.k. for stainless steel jacketing.
Local standards or client's specifications may require higher values.
e.g.
German Standard DIN 4140 requires 0.5mm to 0.8mm minimum thickness in relation to the insulation circumference;
NORSOK standard R-004 requires 0.5mm to 0.7mm in relation to the pipe diameter;
Some Industry Practices (e.g. EXXON) require 0.25mm minimum thickness with thermal insulation, and 0,40mm with noise or noise&thermal insulation.
A minimum thickness for plastic jacketing is not available to me.
