Immersion 1-800-443-2640 www.chromalox.com MT — screwed into tank wall parallel to bottom for use as a hot water rinse. Temperature Control MTO — used to preheat oil to ensure efficient lubrication for heavy motor. MTO — applied to conveyorized degreasing operation of many parts at once. Temperature Control Screw Plug Immersion Heaters Overview Description Screw Plug Immersion Heaters consist of hairpin bent tubular elements brazed or welded into a screw plug and provided with terminal enclosures for electrical connections. Screw Plug Immersion Heaters are screwed directly through a threaded opening in a tank wall or through a matching pipe coupling or half coupling. Sizes of screw plug heaters are available with 1/2, 3/4, 1, 1-1/4, 2 and 2-1/2" pipe threads. A wide selection of screwplug sizes, kilowatt ratings, voltages, sheath materials, terminal enclosures and thermo- stats makes these compact heaters ideal for all types of applications. 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. • Hot Water Storage Tanks • Warming Equipment • Preheating all Grades of Oil • Food Processing Equipment • Cleaning and Rinsing Tanks • Heat Transfer Systems • Process Air Equipment • Boiler Equipment • Freeze Protection of Any Fluid B-2 More Information is Available Online on Tank Heating. Bookmark Your Browser to www.chromalox.com and Select Manuals.
Transcript
Immersion
1-800-443-2640 www.chromalox.com
MT — screwed into tank wall parallel to bottomfor use as a hot water rinse.
TemperatureControl
MTO — used to preheat oil to ensure efficientlubrication for heavy motor.
MTO — applied to conveyorized degreasingoperation of many parts at once.
TemperatureControl
Screw Plug Immersion Heaters
Overview
Description
Screw Plug Immersion Heaters consist ofhairpin bent tubular elements brazed orwelded into a screw plug and provided withterminal enclosures for electrical connections.Screw Plug Immersion Heaters are screweddirectly through a threaded opening in a tankwall or through a matching pipe coupling orhalf coupling. Sizes of screw plug heaters areavailable with 1/2, 3/4, 1, 1-1/4, 2 and 2-1/2"pipe threads. A wide selection of screwplugsizes, kilowatt ratings, voltages, sheathmaterials, terminal enclosures and thermo-stats makes these compact heaters ideal forall types of applications.
Applications
Screw Plug Immersion Heaters are used forheating liquids and gases in a variety ofprocesses. These heaters are ideal for processwater heating and freeze protection. All typesof oils and heat transfer solutions can also beheated using these compact, easily controlledunits. The direct immersion method is energyefficient and well suited for many applications.
• Hot Water Storage Tanks
• Warming Equipment
• Preheating all Grades of Oil
• Food Processing Equipment
• Cleaning and Rinsing Tanks
• Heat Transfer Systems
• Process Air Equipment
• Boiler Equipment
• Freeze Protection of Any Fluid
B-2
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Bookmark Your Browser towww.chromalox.comand Select Manuals .
Immersion
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Water & Very Clean Water pH6 to pH8 Neutral Copper 45 BrassMild Solutions Process Water or pH5 to pH9 Stainless Steel1 45 Stainless Steel
Very Weak Solutions 2-3%Weak Solutions 5-6% INCOLOY® 45 Stainless SteelDemineralized, — INCOLOY® 45 Stainless SteelDeionized water Stainless Steel1 Stainless Steel
Corrosive & High Mild Corrosive Solution 5-15% INCOLOY® or 23 Stainless SteelViscous Solutions Stainless Steel1
Severe Corrosive 16% INCOLOY® or 15 Stainless SteelSolution or more Stainless Steel
The selection of the proper screw plugimmersion heater requires critical engineeringjudgement. After determining the heatrequirement (see the Technical section of thiscatalog), the proper selection of the screwplug material, heating element sheath materialand correct watt density is critical for long lifeof the heater. The following table may be usedas a guide to this selection, along with theTechnical Information at the back of thiscatalog. Ultimate choice is determined by theknowledge of the process and engineeringacumen of the plant engineer.
Application Factors
Heater application is influenced by thefollowing parameters.
1 The heated media, viscosity, specific heat,density and corrosive properties.
2 Contaminants or pH present in the media.
3 The corrosion resistant properties ofheater sheath material.
4 Watt density of the heating element—theheat output per square inch.
5 Screw plug material.
Typical Applications
See screw plug immersion heater selectionguide below for your application.
• Hot Water Storage Tanks
• Warming Equipment
• Preheating all Grades of Oil
• Food Processing Equipment
• Cleaning and Rinsing Tanks
• Heat Transfer Systems
• Process Air Equipment
• Boiler Equipment
• Freeze Protection of Any Fluid
Alkaline orSolution or Acid Content Sheath Watt Density Screw Plug
Application Heater Type (Est. % by Volume) Material (W/In2) Material
1 2 3 4 5
1. Passivated stainless steel recommended for water applications.
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Screw Plug Immersion Heaters
Application Guidelines
Clean Water 1 Copper Brass ARTM Yes B-71-1/4 Copper Brass MT-1 No B-102 Copper Brass EMT-3 No B-152 Copper Brass ARMT-2 Yes B-112 Copper Brass MT-2 No B-132 INCOLOY® Brass CH-SD No B-162-1/2 Copper Brass ARMT Yes B-172-1/2 Copper Brass MT-3 No B-21
Process Water 1 SS SS ARTMS Yes B-232 SS SS ARMTS-2 Yes B-272 SS SS MTS-2 No B-292 SS SS AREMTS-3 Yes B-312 SS SS EMTS-3 No B-322-1/2 SS SS ARMTS-3 Yes B-342-1/2 SS SS MTS-3 No B-36
Solution Water 2 INCOLOY® SS ARMTI-2 Yes B-382 INCOLOY® SS MTI-2 No B-402 INCOLOY® SS AREMTI-3 Yes B-412 INCOLOY® SS EMTI-3 No B-422-1/2 INCOLOY® SS ARMTI-3 Yes B-432-1/2 INCOLOY® SS MTI-3 No B-45
Corrosive Solutions 2 SS SS AREMTS-3 Yes B-462 SS SS EMTS-3 No B-472 INCOLOY® SS AREMTI-3 Yes B-482 INCOLOY® SS EMTI-3 No B-49
Severely 2 SS SS AREMTS-3 Yes B-50Corrosive 2 SS SS EMTS-3 No B-51Solutions 2 INCOLOY® SS AREMTI-3 Yes B-52
2 INCOLOY® SS EMTI-3 No B-53Light Weight Oil 1 Steel Steel ARTMO-1 Yes B-54
1-1/4 Steel Steel MTO-1 No B-572 Steel Steel ARMTO-2 Yes B-582 Steel Steel MTO-2 No B-602 Steel Steel AREMTO-3 Yes B-612 Steel Steel EMTO-3 No B-622-1/2 Steel Steel ARMTO-3 Yes B-632-1/2 Steel Steel MTO-3 No B-65
Medium Weight Oil 2 Steel Steel ARMTO-2 Yes B-672 Steel Steel MTO-2 No B-682 Steel Steel AREMTO-3 Yes B-692 Steel Steel EMTO-3 No B-702-1/2 Steel Steel ARMTO-3 Yes B-712-1/2 Steel Steel MTO-3 No B-72
Heavy Weight Oil 2 Steel Steel ARMTO-2 Yes B-732 Steel Steel MTO-2 No B-742 Steel Steel AREMTO-3 Yes B-732 Steel Steel EMTO-3 No B-742-1/2 Steel Steel ARMTO-3 Yes B-752-1/2 Steel Steel MTO-3 No B-75
Specialty Heaters — 1/2 INCOLOY® Steel RI No B-79Water, Oil & 1/2 SS Steel RIO No B-79Corrosive Fluids 1/2 INCOLOY® Brass RIN No B-80
1/2 SS Brass RINO No B-801/2 SS SS RIS No B-793/4 INCOLOY® Steel RI No B-793/4 SS Steel RIO No B-793/4 INCOLOY® Brass RIN No B-803/4 SS Brass RINO No B-801 Copper Brass TMW-1 No B-761 SS SS TMWS-1 No B-761 Steel Steel TMO-1 No B-781-1/4 Copper Brass TMW-2 No B-772 INCOLOY® Brass DWH Yes B-81
Note — SS denotes 304 Stainless Steel.
Application Element — Guidelines
Screw Plug Sheath Screw Plug Heater IntegralApplication Size (In.) Material Material Model Thermostat Page
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Screw Plug Immersion Heaters
Technical & Application Data
Description
Chromalox heavy duty tubular elements arewelded or brazed to a screw plug. Uniformheat distribution and repressed elementbends, a Chromalox standard feature, lead tolong element life. For all heaters, a thermowell(hollow tube sealed at one end) is welded orbrazed to the screw plug allowing thermostatsensing element replacement without drainingthe tank. A variety of methods of terminatingpower leads is available for special applicationheaters.
General purpose screw plug heaters areequipped with a steel terminal enclosurepainted with red enamel. These same heatersare also available with a combination moisturetight/explosion resistant terminal enclosurethat may be used in applications where eitheror both conditions exist.
Screw plug type heaters are screwed directlythrough a threaded opening in the tank wall.Heavy tank walls may be drilled and tapped ifthickness is sufficient to engage 3/4 of thethreads. Lighter tank walls should beequipped with a suitable pipe half-couplingwelded or brazed to the tank wall.
• Tolerances — Tolerance on immersionlength (B) dimension is ± 1% (± 3/8" min.).
Terminal Enclosures
Type E1 General purpose, sheet metal, paintedwith red enamel. The terminal enclosurerotates 360° to accommodate an electricalconduit run.
Type E4 Moisture resistant housing.
Type E2 Combination moisture resistant/explosion resistant.
Type E2 explosion resistant enclosures are foruse in hazardous location conditions:
• Class I Groups B, C & D, Division 1 & 2
• Class II, Groups E, F & G, Division 1 & 2
• Class III, Division 1 & 2.
Safe operation of heaters equipped withexplosion resistant enclosures depends onelectrical wiring meeting the National ElectricalCode for hazardous locations and on limitingthe maximum operating temperatures(including temperatures on outside of vessel,piping, flanges, screw plugs, enclosures andother heat conducting parts) as dictated byflammable liquids, vapors or gases present.Approved pressure and/or temperaturelimiting controls must be used to assure safeoperation in the event of a systemmalfunction.
Temperature Controls
Many screw plug type heaters are availablewith built-in thermostatic controls. In someinstallations where there is more than oneheater in a tank, one heater with a built-incontrol can be used to control the otherheaters by wiring the thermostat into theholding coil circuit of a magnetic contactor. Ifthe thermostat is separate from the heater, thethermostat sensing element should be locatedin the liquid approximately 4 to 6 inches abovethe heater.
1 and 1-1/4" Screw Plugs — Type ARTM,ARTMO and ARTMS. The ARTM, ARTMO orARTMS automatic thermostat has a tempera-ture range of 60°F - 187°F (T4). Also available
with alternate temperature 60°F -240°F (T5) or0°F - 127°F (T8). The tamper resistanttemperature adjustment screw and scale areinside requiring the removal of the cover tochange temperature setting.
2 and 2-1/2" Screw Plugs — Type ARMT,ARMTI, AREMTI, ARMTS, AREMTS, AREMTOand ARMTO. The integral thermostat isavailable with temperature ranges at60°F - 250°F (T2) or 0°F - 100°F (T1) forARMT, ARMTI, AREMTI, AREMTS and ARMTSheaters. ARMTO and AREMTO heaters areavailable with three different temperatureranges: 200°F - 550°F (T3), 60°F - 250°F (T2)and 0°F - 100°F (T1). This control is wired inas a line thermostat for loads up to 3 kW on120 volts and up to 6 kW on 240 volts. Forhigher wattage ratings, three phase operationand above 240 volts, this control is used forpilot duty only and should be wired to operatethe holding coil of a magnetic contactor.
To set the control temperature of heatersequipped with the standard general purposeenclosure (Type E1), adjust the knob on theoutside of the terminal enclosure.
For those heaters equipped with a Type E2 andE4 enclosure, remove the terminal enclosurelid to expose the temperature adjusting knob.For safety reasons, power to heater and pilotduty power must be turned off beforeremoving enclosure lid.
Note — The integral thermostat functions as atemperature control only. This is not a fail safedevice, so an approved pressure and/ortemperature limit control should be used withthese heaters to assure safe operation.
CAUTION — Explosion Resistant Type E2construction refers to heater design featureswhich provide explosion resistant containmentof electrical wiring according to NationalElectrical Code. Application or use of heaterswhich result in abnormal or excessivetemperature can create hazardous conditionswhich can lead to a fire or explosive condition.
Corrosion Policy
Chromalox cannot warrant any electricimmersion heater against failure by sheathcorrosion if such failure is the result ofoperating conditions beyond the control of theheater manufacturer. It is the responsibility ofthe purchaser to make the ultimate choice ofsheath material based on their knowledge ofthe chemical composition of the corrosivesolution, character of materials entering thesolution, and controls which he maintains onthe process.
Construction Features —Stock & Assembly Stock Units
• Number Elements in Screw Plug — 1, 2 or3 depending on screw plug size.
• Element Diameter — 0.315, 0.375, 0.430and 0.475".
• Watt Density — 6.5, 15, 23, 45 and 75 W/In2.
Standard PipeThread
Elements
Thermowell
PipeCoupling
Weld
Tank Wall
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Screw Plug Immersion Heaters
Optional Features
Moisture Resistant TerminalEnclosure Option
• Cast Aluminum Construction
• Red Epoxy Paint Finish
• O-Ring Sealed Housing Cover
• Threaded 3/4" NPT Conduit Fitting
Description
A moisture resistant only (not explosionresistant) terminal enclosure is available on allscrew plug immersion heaters.
To Order
Add E4 to end of model number of the generalpurpose enclosure heater for moistureresistant construction only. Specify volts,phase and kilowatts. Do not order by PCN.
Small Screw Plug Enclosure — Dimensions (Inches)
4-13/32
5-5/16
3-1/4
Large Screw Plug Enclosure — Dimensions (Inches)
3-27/32
6-13/16
5-7/16
7-13/16
5-19/32
Note — For all heaters without thermostats and 1" and 1-1/4" NPT heaters with thermostats.
Note — For 2 and 2-1/2" NPT heaters with thermostats.
