Cheers Travis. Appologies for the lack of detail. The working temperature is 5 C and the pipe runs 1.5m horizontal with a 2.5 m vertical climb feeding a storage tank. I similarly suspect it may require trace heating but do think it is borderline.
I am trying to ascertain if a 150NB Stainless Steel pipe lagged with 50mm thick insulation would also require to be trace heated. The insulation used is rockwool. The parameters are that the pipe must not freeze solid given 5 straight days of -15 C with static flow. Wind chill is negligible. The...