The only Raychem brand products I have used - winterguard and Icestop series both use a self regulating design that goes down to 2 watts per foot.
Do you consider these as being
uncontrolled temperature designs?
Just curious.
Unregulated means that you are not using a temperature sensor on the piping to control the power to the trace.
The temperature I am referring to is the maximum temperature that the self regulating heat trace can reach. If the pipe being traced does not have flow and is well insulated, it is possible for the trace to reach this temperature. If there is flow, less insulation and lower temperatures the heat loss may prevent the trace from ever reaching this temperature...the maximum is a worst case number.
I looked a bit last night for that temperature for the winterguard trace, but did not find it. The 150 came from some of their other lines of self regulating trace. In any case, to be sure if the trace it suitable for the application, you need to find the maximum uncontrolled temperature that the trace can reach and compare that to the maximum permitted temperature for the item being traced.
The first sentence should read: Uncontrolled means .....