Pipe Heating in a narrow range of temperature

We are a chemical company  searching for a suitable technology to get metal pipes from 1/2" up to 2-3" in diameter heated in a narrow range of temperature: Below 44ºC the product gets solidified, and above 83ºC the product is degradated and loses its chemical properties. 

We are interested in knowing which companies can provide this technology, and what is the best option for heating: whether it is a jacketed heating pipe with hot liquid or steam, a traced  pipe or a electrical heating system for the pipe.

Please provide the name of your company, the description of your technology and a list of projects were you have applied successfully  that technology for maintaining pipes into a 40ºC range of temperature, or in case not yet implemented please justify why you think that your technology can be applied to our case.

Thanks and best regards