Flange Hub

Flanged Immersion Heaters

Flanged Immersion Heaters are designed for use in tanks and pressurized vessels to heat both liquids and gases. They mate to a companion flange that is either welded to a tank wall or, for circulating type heaters, to a pipe.

Flange size	Flange Mounting			Flange Thickness “F”		Mounting Bolt Circle “C”		Flange Diameter “D”		Cold Section “S”		Bundle Diameter “H”		NEMA 1 Housing				Number of Elements
Flange size	Hole Size		No.	Flange Thickness “F”		Mounting Bolt Circle “C”		Flange Diameter “D”		Cold Section “S”		Bundle Diameter “H”		“K”		“L”		Number of Elements
in	in	mm		in	mm	in	mm	in	mm	in	mm	in	mm	in	mm	in	mm	Std.	Max.
3	3/4	19	4	15/16	24	6	152	712	191	4	102	2-3/4	70	4-5/8	117	3-1/8	79	3	6
4	3/4	19	8	15/16	24	7-1/2	191	9	229	4	102	3-7/8	98	6	152	4	102	6	6
5	7/8	22	8	15/16	24	8-1/2	216	10	254	4	102	5	127	7	178	4	102	6	9
6	7/8	22	8	1	25	9-1/2	241	11	279	4	102	6	152	8	203	6	152	12	15
8	7/8	22	8	1-1/8	29	11-3/4	298	13-1/2	343	6	152	7-13/16	198	10	254	6	152	18	24
10	1	25	12	1-3/16	30	14-1/4	362	16	406	6	152	9-3/4	248	11-5/8	295	6	152	27	36
12	1	25	12	1-1/4	32	17	432	19	483	6	152	11-3/4	298	13-1/2	343	6	152	36	54
14	1-1/8	29	12	1-3/8	35	18-3/4	476	21	533	6	152	12-3/4	324	15-1/8	384	6	152	45	72

Typical Applications

Low Carbon Steel Sheath—Applications include fluid heat transfer media, tar, high to low viscosity petroleum oils, asphalt, wax, molten salt, and other solutions not corrosive to a steel sheath.

Steel Sheath Heaters 8 watts/sq.in.
Applications: Fuel Oils (Bunker C and Number 6)

Steel Sheath Heaters 15 watts/sq.in.
Applications: Fuel Oils (Number 4 and 5)

Steel Sheath Heaters 23 watts/sq.in.
Applications: Lightweight Oils, Heat Transfer Oils, Degreasing Solutions

Copper Sheath—Mainly used in clean water heating for washrooms, showers, rinse tanks and freeze protection of storage tanks.
Copper Sheath Heaters 60 watts/sq.in.
Applications: Clean Water

Incoloy� 800 Sheath— A Nickel (30-35%), Chromium (19-23%), Iron alloy. 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 that are not corrosive to an Incoloy� 800 sheath

Incoloy Sheath Heaters 16 watts/sq.in.
Applications: Heat Transfer Oils, Liquid Paraffin

Incoloy Sheath Heaters 23 watts/sq.in.
Applications: Forced Air, Caustic Solutions, Degreasing Solutions

Incoloy Sheath Heaters 48 watts/sq.in.
Applications: Process Water

316 Stainless Steel Sheath—A Chromium (16-18%), Nickel (11-14%), Iron Alloy with Molybdenum (2-3%) added to improve corrosion resistance in certain environments, especially those that would tend to cause pitting due to the presence of chlorides. Applications include deionized water.
316 Stainless Steel Sheath Heaters 60 watts/sq.in
Applications: Deionized Water

Optional Element Sheath Materials

304 Stainless Steel— A Chromium (18-20%), Nickel (8-11%), Iron Alloy used in the food industry, sterilizing solutions, air heating and many organic and inorganic chemicals.

321 Stainless Steel— A Chromium (17-20%), Nickel (9-13%), Iron Alloy modified with the addition of titanium to prevent carbide precipitation and the resulting intergranular corrosion that can take place in certain mediums when operating in the 800-1200�F (427-649�C) temperature range.

Surface Metal Treatments

Flanged Immersion Heater surfaces in contact with the material being heated can be passivated or electro-polished to improve their resistance to corrosion.

Passivation removes surface contamination, usually iron, so that the optimum corrosion resistance of the stainless steel is maintained. Surface contamination would come from the small amount of steel that may be worn off a tool during the manufacturing process. Passivating is accomplished by dipping the heater in a warm solution of nitric acid.

Electro-Polishing is an electrochemical process that removes surface imperfections and contaminants, enhancing the corrosion resisting ability of the stainless steels. The resultant surface is clean, smooth and bright. Many medical and food applications require this finish.

Selecting the proper Flanged Heater

Tempco Screw Plug Immersion Heaters will provide long life and dependable trouble free service—provided the sheath materials, watt densities and operating temperatures are properly matched for the medium being heated.

Observe the following guidelines:

Match your process to the most suitable heater alloy sheath material.
Do not exceed the maximum allowable heater watt density (w/in2) and recommended operating temperature for the material being heated.
Select the proper terminal enclosure to protect the heater wiring and provide safety to personnel and equipment.
On large tanks, use several smaller KW rated heaters rather than one large heater for uniform heat and watt density distribution.

Watt Density

Element Watt Density is the wattage dissipated per square inch of the element sheath surface. For a particular application element watt density will govern element sheath temperature. Factors to consider when choosing a suitable watt density are:

Many materials are heat sensitive and can decompose or be damaged if the element is running too hot.
Air and other gases that are poor conductors of heat require watt densities matched to the velocity of the gas flow to prevent element overheating.
Mineral deposits when heating hard water and cleaning solutions can build up on the element sheath, acting as a heat insulator and raising the internal element temperature. If these deposits cannot be periodically removed, use a lower watt density element to increase heater life expectancy.