Flanged Immersion Heaters

Flanged Immersion HeaterFlanged immersion heaters are high capacity electrical heating units made for tanks or pressurized vessels. They consist of multiple tubular heaters formed into hairpin and welded or brazed to flanges. The heating elements could be made of copper, steel, stainless steel or Incoloy sheath. Standard flanges are carbon steel rated for 150 or 300 Lbs. Other flange materials and shapes are available. Various types of electrical protection housing, built in thermostats, thermocouples and high limit switches can be incorporated.  

FLANGE SELECTION GUIDE

  150 Lbs. Flange detail rating 300 Lbs Flange detail rating
Size Max # of elements Standard cold end                    O.D. Flange thickness # Holes Holes diameter B.C.         O.D.      Flange thickness # Holes Holes diameter B.C.                  
2.5" 3 5 1/2" 7" 7/8" 4 3/4" 5 1/2" 7 1/2" 1" 8 7/8" 5 7/8
3" 6 5 1/2" 7 1/2" 15/16" 4 3/4" 6" 8 1/4" 1 1/8" 8 7/8" 6 5/8"
4" 9 5 1/2" 9" 15/16" 8 3/4" 7 1/2" 10" 1 1/4" 8 7/8" 7 7/8"
5" 9 6 3/4" 10" 15/16" 8 7/8" 8 1/2" 11" 1 3/8" 8 7/8" 9 1/4"
6" 18 6 3/4" 11" 1" 8 7/8" 9 1/2" 12 1/2" 1 7/16" 12 7/8" 10 5/8'
8" 30 6 3/4" 13 1/2" 1 1/8" 8 7/8" 11 3/4" 15" 1 5/8" 12 1" 13"
10" 48 10" 16" 1 3/16 12 1" 14 1/4" 17 1/2" 1 7/8" 16 1 1/8" 15 1/4"
12" 60 10" 19" 1 1/4" 12 1" 17" 20 1/2" 2" 16 1 1/4" 17 3/4"
Bundle diameter to suit sch. 80 pipe

 

INDUSTRIAL APPLICATIONS

  • HOT WATER TANKS

  • BOILER HEATERS

  • ASPHALT, PARAFFIN, WAX HEATERS

  • OIL PRODUCT HEATERS

  • CORROSIVE AND NON-CORROSIVE SOLUTIONS

  • AIR AND GAS HEATERS

  • HEAT TRANSFER EQUIPMENT

  • VAPOR DEGREASERS

OPTIONAL FEATURES

  • NEMA 4 TERMINAL BOX

  • NEMA 7 TERMINAL BOX

  • 300 LB RATED FLANGES

  • STAINLESS STEEL FLANGES

  • SPECIAL TERMINAL BOX (STILTED, VENTED, STAINLESS STEEL, ETC…)

  • BUILT-IN THERMOCOUPLES

  • PASSIVATION

  • BAFFLES

  • THERMOSTATS WITH VARIOUS TEMPERATURE RANGES

  • HIGH LIMIT TEMPERATURE DEVICES

 

Flanged immersion heaters can be used in different applications. In order to meet the heating requirements of a specific application and have a safe operation in the environment within which a heater operates several factors should be taken into consideration in the design of flanged immersion heaters. The following are a number of criteria that should be considered:

  • The pressure rating and the material of a flange.
  • The sheath material of the tubular elements. Table 2 provides recommended tubular element sheathe and flange materials for different mediums.
  • Operating temperature and a watt density of tubular elements that are adequate to the material heated. Table 2 provides maximum operating temperatures and watt densities that are recommended for heating various materials.
  • Design watt density, flow velocity, outlet temperature are factors that contribute to the temperature level that tubular elements will attain. The table below shows the maximum temperatures that different sheath materials could be subjected to:
Sheath Material Maximum Temperature
Copper 3600 F (1800 C)
Stainless Steel 12000 F (6500 C)
Steel 7500 F (4000 C)
Incoloy 15000 F (8150 C)
  • Safety issues considering the environment within which the immersion heater will operate.
  • Utilization of adequate temperature controlling devices, temperature and pressure high limit switches, low liquid level and flow controllers and other control/safety devices that will control the heating process and protect the heater from excessive heat.
  • The classification of the electrical terminal box required (NEMA1, NEMA4, NEMA7, NEMA12 etc…).
  • The level of the contamination that the immersion heater will be exposed to
  • Safety and electrical code consideration
  • The possible requirement of baffles that force a gas or a liquid to circulate around heating elements when flanged immersion heaters are used inside circulation tanks.

For more information in selecting Flanged immersion heaters please contact Bucan.

 

Application Sheath Material Flange Typical Watt Density
Clean water Copper Steel 45
Process water/Weak solution Stainless Steel Stainless Steel 25-55
Oil light Steel Steel 20-25
Oil medium Steel Steel 12-15
Corrosive solutions Incoloy Stainless Steel 20-25
Vegetable oil Stainless Steel Stainless Steel 25-30
Asphalt, tar, wax Steel Steel 6
Air Incoloy Steel 23

 

 

THERMOSTATS AND THERMOCOUPLES

The thermostats used in flanged immersion heaters are the bulb and capillary style. The standard thermostat has 25A max capacity and could operate up to 240V. This thermostat is single pole/single throw style with a temperature range of 10-120ºC. The table below shows other ranges of thermostats that are available.

THERMOSTAT CONTACT OPERATION TEMPERATURE RANGE MAXIMUM AMPS MAXIMUM VOLTAGE
T SPST 100  to 1200 C 25A 277V
T1 SPST -180 to 400 C 25A 277V
T2 SPST 700 to 2800 C 25A 277V
T3 SPST 1600 to 3700 C 25A 277V
T4 DPST 100 to 1200 C 15A 600V
T5 DPST -180 to 400 C 15A 600V
T6 DPST 700 to 2800 C 15A 600V
T7 DPST 1600 to 3700 C 15A 600V

 

It should be noted that thermostats are only temperature controllers and should not be used as fail-safe high limit switches.

Built-in thermocouples could be used inside flanged immersion heaters to give more accurate temperature indications. Thermocouples could also be attached to one of the heating elements and used as high-temperature limiting devices.

 

 

  Terminal Box Size
  Flange Without Thermostat With Thermostat
  Size Fig. # Dim.A Dim.B Dim.A Dim.B
NEMA1 2.5" 1 - 3'' - 4.5''
3" 1 - 3'' - 4.5''
4" 1 - 4.5'' - 4.5''
5" 1 - 4.5'' - 4.5''
6" 1 - 4.5'' - 4.5''
8" 1 - 4.5'' - 4.5''
10" 1 - 7.5'' - 7.5''
12" 1 - 7.5'' - 7.5''

 

NEMA4 2.5" 3 or 4 -   -  
3" 2 - 4 1/2" - 7 1/4"
4" 2 - 4 1/2" - 7 1/4"
5" 2 - 7 1/4" - 7 1/4"
6" 2 - 7 1/4" - 7 1/4"
8" 2 - 7 1/4" - 7 1/4"
10" 2 - 8'' - 8''
12" 2 - 8'' - 8''