Screw Plug Heaters/ Screw-Plug Immersion Heaters:
Screw-Plug Immersion Heaters with General Purpose & Nema 4 Enclosures- Industrial Process/Tank Heaters
Product Description Guide and Construction-Screw-Plug Immersion Heaters:A Screw Plug Immersion Heater can have from 1 to 3 tubular elements, or blades, either welded or brazed into the screw plug. Screw plug immersion heaters consist of hairpin bent tubular elements brazed or welded into a screw plug and provided with terminal boxes for electrical connections. Screw plug immersion heaters are screwed directly through a threaded opening in a tank wall or through matching pipe coupling, half coupling or welding flange. Sizes of screw plug heaters are available with 1/2", 3/4" 1", 11/4", 2" and 21/2" pipe threads. A wide selection of screw plug sizes, kilowatt ratings, voltages, sheath materials, terminal housings, and thermostats makes these compact heaters ideal for all types of applications. Screw plug immersion heaters are used for heating liquids and gases in a variety of processes. These heaters are ideal for process water heating and freeze protection. All types of oils and heat transfer solutions can also be heated using these compact easily controlled units. The direct immersion method is energy efficient and well suited for many applications.
Screw-Plug Immersion Heaters-Construction Components
Screw-Plug Immersion Heaters: Specifications, Manuals, Technical Letters & Tips:
Screw Plug Immersion Heater - Features:
Most Common Screw Plugs:
Most Common Sheath Material:
Other Sheath Material Also Offered:
Most Common Terminal Enclosures:
1" NPT (National Pipe Thread) Screw-Plug Heater Construction
Safe operation of heaters equipped with these enclosures depends on employment of electrical wiring meeting National Electric Code and limiting maximum operating temperatures (including temperatures on outside of vessel, piping, flanges, screw-plugs, enclosures and other heat conducting parts) as dictated by flammable liquids, vapors, or gases present. Approved pressure and/or temperature limiting controls must be used to assure safe operation in the event of system malfunction.
Common Nema Enclosure TypesNEMA 1 - General purpose indoors. Basic enclosure intended to prevent accidental contact with internal electrical components. Suitable for use indoors where not subjected to unusual conditions.
NEMA 4 - Watertight and dusttight indoors or outdoors. Designed to exclude water applied in the form a hose stream. Also suitable where apparatus may be subjected to a stream of water during cleaning operations.
NEMA 4x - Watertight, dusttight, and corrosion resistant - indoors or outdoors. Protects internal components against splashing water, falling or hose directed water, and severe external condensation. Sleet resistant. Corrosion resistant material or finish.
NEMA 7 - Explosion resistant in hazardous class 1 locations (areas where flammable gases or vapors are or may be present in quantities to produce explosive conditions or fire).
NEMA 12 - Dusttight and driptight indoors. Enclosures are designed to protect internal components from fibers, lint, dust, dirt and light splashing, and dripping of non-corrosive liquids.
Terminal Enclosure Types - General purpose, sheet metal, (NEMA-1) painted with enamel. Moisture Resistant-Nema 4, Nema 4X, Explosion Proof Nema 7.
Grounding Connector Standard - A solid terminal connector is standard on all NPH immersion heaters insuring positive ground and personal safety.
Built In Thermocouple Options:
Built In Thermostats:Power Ratings:
Listed below are some of the recommended watt densities to heat various fluids and gases:(a) 90, 60 & 45 Watts/Square InchFor industrial water heating of many acqueous solutions which accept heat easily.(b) 23 Watts/Square InchIndustrial process heating of many light oils and cooling fluids for some corrosive solutions along with air and gas heating.(c) 15 & 12 Watts/Square InchFor industrial heating of medium viscosity oils, high temperature air and gas heating.(d) 8 Watts/Square InchFor heating of #5 and #6 fuel oil, viscous materials, raw crude oil and residual oils(e) 6 Watts/Square InchFor heating #6 fuel oil, very viscous materials and fluids that do not accept heat readily.
Specifications, Manuals, Technical Letters & Tips:
Construction-Flanged Immersion Heaters ( Or have above a link to new page) Screw Plug Immersion Heaters Specifications.pdf How to Extend the Life of Your Immersion Heaters-2.pdf Screw Plug Immersion_Heaters_Wiring_Diagrams-2.pdf Screw Plug Immersion Heaters-Installation, Operation and Maintenance Instructions.pdf
National Plastic Heater Corrosion Policy:
NPH cannot warrant any electric immersion heater against failure by sheath corrosion if such failure is the result of operating conditions beyond the control of the heater manufacturer. It is the responsibility of the purchaser to make the ultimate choice of sheath material based on his knowledge of chemical composition of corrosive solution, character of materials entering the solution, and controls which he maintains on the process. * Not intended for use in hazardous locations.
How To Order Screw Plug Immersion Heaters