WATROD™ and FIREBAR® Screw Plug Immersion Heaters

Ideal for Direct Immersion Heating of Liquids

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

related documentation

  • User Manuals

    FIREBAR Flange Heater Installation & Maintenance Manual

    FIREBAR Screw Plug Installation & Maintenance Manual

    Thermostat Control Installation & Maintenance Manual

    WATROD Circulation Heater Installation & Maintenance Manual

    WATROD Duct Heater Installation & Maintenance Manual

    WATROD Duct Heater (Module Only) Installation & Maintenance Manual

    WATROD & FIREBAR Installation & Maintenance Manual

    WATROD Flange Heater Installation & Maintenance Manual

    WATROD Modular Duct Heater Installation & Maintenance Manual

    WATROD Over-the-Side Installation & Maintenance Manual

    WATROD Screw Plug Installation & Maintenance Manual

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    Watlow's Heating Solutions For Your Applications

  • Catalogs

    Thermal Component Reference Guide

    Heater Catalog (Section) - Agency Certifications

    Heater Catalog (Section) - Heater Reference Data

    Heater Catalog (Section) - Heater Selection Matrix

    Heater Catalog (Section) - Immersion Heaters

    Heaters Catalog

  • Specification Sheets

    316 Stainless Steel Heaters

    Circulation Heaters

    Duct Heaters

    FIREBAR/Tubular Heaters

    Flange Immersion Heaters

    High Temperature Tubular Heater

    Screw Plug Immersion Heaters

    WATROD Tubular Heaters

    Watlow Process Solutions

  • Other Documents

    Humidity Conditioning Requirements of Commercial Electric Cooking Appliances per UL 197

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quality certificates 1

ISO 9001-2008 Hannibal