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Heaters, Sensors, Controllers, Relays, Linear Displacement, and Leadwire

Screwplug Immersion Heaters

Standard Lead Times

  • 1“, 1 1/4”, 2” and 2 1/2” NPT pipe plug in brass, steel or stainless steel
  • .312” diameter element(s) on 1” and 1 1/4”; .430” diameter elements on 2” and 2 1/2”
  • Copper, steel, 321 stainless steel, or Incoloy 800 sheath material
  • High, medium and low watt densities for various processes
  • General purpose or explosion and moisture resistant terminal enclosures
  • Bends are repressed after forming to recompact MgO and extend element life
  • Single and double pole thermostats in several temperature ranges
  • Copper Sheath: Clean water, freeze protection, hot water storage, cooling towers, heating of solutions not corrosive to copper
  • Stainless Steel Sheath: Process water, soap and detergent solutions, soluble cutting oils, demineralized or delonized water (passivation recommended)
  • lncoloy Sheath: Solution water, corrosive solutions, steam super heating, air or gas
  • Steel Sheath: Asphalt, wax, paraffi n, tar, etc., heat transfer medium, petroleum, degreasing and solvent oils, machine oil, fuel oils, alcohol
Screwplug Sizes & Materials
Screw Plug MaterialInformation
Brass Screw PlugUsed for clean water and other non-corrosive materials
304 SS Screw PlugUsed for corrosive materials
316 SS Screw PlugUsed for corrosive materials
Steel Screw PlugUsed for oils and other non-corrosive materials

**BSPP Threads also Available**

Watt Densities for Typical Applications
Watt DensityTypical ApplicationScrewplug MaterialElement Material
8 watts/in2 (1.3 watts/cm2)Fuel Oils (Bunker C and Number 6)SteelSteel
15 watts/in2 (2.3 watts/cm2)Medium Weight Oils ● Heat Transfer OilsSteelSteel
16 watts/in2 (2.5 watts/cm2)Medium Weight Oils ● Heat Transfer Oils ● Liquid Paraffin304 Stainless SteelIncoloy® 800
23 watts/in2 (3.6 watts/cm2)Forced Air & Gases ● Caustic Solutions ● Degreasing Solutions304 Stainless SteelIncoloy® 800
23 watts/in2 (3.6 watts/cm2)Lightweight Oils ● Degreasing Solutions ● Heat Transfer OilsSteelSteel
48 watts/in2 (7.5 watts/cm2)Process Water304 Stainless SteelIncoloy® 800
60 watts/in2 (9.3 watts/cm2)Clean WaterBrassCopper
60 watts/in2 (9.3 watts/cm2)Deionized Water ● Demineralized Water316 Stainless Steel316 Stainless Steel
Sheath Materials
Sheath MaterialInformation
Incoloy 800Nickel 30-35%, Chromium 19-23%, Iron balance.
The high nickel content of this alloy contributes to its resistance to scaling and corrosion. Used in air heating and immersion
heating of potable water and other liquids.
316/316L Stainless SteelChromium 16-18%, Nickel 11-14%, Iron balance.
(316L – Low Carbon)
Modified with the addition of Molybdenum (2-3%) to improve corrosion resistance in certain environments, especially those which would tend to cause pitting due to the presence of chlorides. Applications include deionized water.
Maximum Sheath Temperature: 1200°F / 649°C
304/304L Stainless SteelChromium 18-20%, Nickel 8-11%, Iron balance.
(304L – Low Carbon)
Used in the food industry, medical, and chemical heating.
Maximum Sheath Temperature: 1200°F (649°C)
CopperStandard Copper Alloy
A low temperature, inexpensive material used mainly for clean water heating.
Maximum Sheath Temperature: 350°F / 177°C
SteelLow Carbon
Used for high to low viscosity oils, asphalt, tar, wax, molten salt, heat transfer liquid media and other compatible solutions.
Type of ThermostatDescription
DPST ThermostatDouble Pole – Single Throw Thermostats
SPST ThermostatSingle Pole – Single Throw Thermostats
Adjustable Thermostat w/ Manual Reset High LimitFor single & 3 phase circuits. Adjustable Temperature Control w/ Manual Rset high limit