Abstract: A thermowell apparatus for a Petrochemical Application where a temperature sensing probe is used for a high temperature cracking furnace. The sensing probe is mounted on a flow line of the furnace fired processing unit. The tip member of the probe extends into the cross-section of the pipe. The probe member has a tear shaped design in transverse cross-section which is arranged with a leading edge surface to deflect the fluid flow and thereby increase the life expectancy of the tip member.

Abstract: An elongate tubular member with a seamless frusto-conical interior wall surface having a selected taper angle of typically 5.degree. or less which is formed from a metal tubular member of ductile material and circular wall cylinder configuration by the process of sequentially expanding contiguous length segments of the ductile tubular member to an interior frusto-conical wall configuration. The process involves inserting the tubular member into a female die member which defines an interior frusto-conical surface with a selected cone angle of typically 10.degree. or less with the tubular member coaxially aligned with the die member interior surface.