To calculate the heat energy ? pressures (Inlet & Outlet + m flow rate in Lb/hr are given?

When the gas expands in the CNG regulator, the Joules –Thompson cooling affect can cause some regulators to malfunction aka ‘freeze’. I am sure the freeze point of the regulator will vary with the regulator brand but for this exercise, I think it sufficient to estimate the energy absorbed as the gas expands in the worse case of 3600 psi to 100 psi at 120 pounds per hour flow.