Screw Plug Heaters

Watlow SELECT™

Screw plug immersion heaters are ideal for direct immersion heating of liquids, including all types of oils and heat transfer solutions.

Available in a variety of sizes, Watlow screw plug immersion heaters feature both WATROD round and FIREBAR flat tubular elements.

Heating elements are hairpin bent and either welded or brazed into the screw plug, depending on element sheath and plug material compatibility.

General purpose terminal enclosures are standard with optional moisture resistant, explosion resistant and explosion/moisture resistant enclosures available to meet specific application needs.

Optional thermostats provide convenient process temperature regulation to the screw plug immersion heater.

Features & Benefits

UL® and CSA component recognition

A variety of element sheath and screw plug materials to meet your application needs

Integral thermowells provide convenient temperature sensor insertion and replacement without draining the fluid being heated

Terminal enclosures provide ability to be rotated to simplify connection with existing conduits

Welding or brazing WATROD and FIREBAR elements to the screw plug for a pressure tight seal


Maximum Operating Temperatures
Maximum Watt Densities
Alloy 800/840 1600 870 120 18.6
Stainless Steel 1200 650 120 18.6
Steel 750 400 120 18.6
N/A 350 175 120 18.6
Launch Visual Designer™ Request A Quote Get Application Assistance

Quality Certificates