Chromalox PN401 Preparation of Tank to Receive Heater, Installation of Heater Assembly in Tank

PREPARATION OF TANK TO RECEIVE HEATER

9-1/2” ± 1/4” Dia. Hole

8 - 3/8” - 11 Drilled and

Manhole Cover Adapter Assy.

13” Dia.	By Customer
(See Note 1)
By Customer
	22-1/2”
Conduit
Opening
	8 - 3/8” - 11 Drilled and
Manhole Cover	Tapped Equally Spaced
	Holes on 11-3/4” B.C.

3/8” Min.

Machining of Manhole Cover to Receive

FXTH Immersion Heater Terminal Box

1.Surface on top side of Tank Cover must be suitable for good gasket seating. The 13" dia. area containing the gasket seat must be free of loose scale and rust and shall have a maximum surface roughness of 250 RMS.

2.Bolt hole orientation to axis of storage tank is not important.

Figure B

Tapped Equally Spaced

Holes on 11-3/4” B.C.9-1/2” ± 1/4” Dia. Hole By Customer

13-1/2” O.D.	3/4”
By Customer
1/4”	8”
Manhole Cover

9-1/4” ± 14” By Customer

Machining of Manhole Cover to Receive

FXTH Immersion Heater Adapter Assembly

1.This Dimension is for Storage Tank Clearance Hole.

Figure C

1.Double check internal dimensions of tank to be sure heater legs will stand straight on portion of tank bottom to its full length when in its operating position.

2.Remove any obstructions which may interfere with proper instal- lation of heater into tank.

3.Clean manhole area to eliminate dirt and water which can be picked up by heater during its insertion into tank.

4.Time the installation so oil level in tank is half full or less. This will greatly facilitate insertion and positioning of heater.

5.Check sludge in bottom of tank to ensure it does not interfere with operation of heater. Standard FXTH heaters are supplied with 4” sludge legs. Sludge in excess of 3” must be removed before

installing heater. Sludge must not touch the corrugated heating surface of the immersion unit.

6.Check point of tank suction to make sure it is 12” or more off bot- tom of tank. This will insure a minimum liquid level of 12” and prevent heater from being uncovered while in operation. The heater must not be energized unless it is completely submerged.

7.Machine manhole cover per Figure B or install optional terminal housing manhole adapter to manhole cover or storage tank per Figure C. All welds must be liquid tight.

DANGER: Hazard of Fire. If adapter is to be welded directly into tank, remove flammable liquids, and vent all combustible gases or vapors from storage tank before performing welding operations.

INSTALLATION OF HEATER ASSEMBLY IN TANK

1.If tank is type with manhole located near end of tank rather than in center, install a temporary pulling cable at far end of tank through any available port such as (l) fill pipe, (2) suction port, (3) auxiliary manhole, etc., and thread the cable through the tank and out the manhole to be used for installing the heater. The pulling cable will be used to pull front lifting cable through auxiliary port and then pulling cable is disconnected. See Figure D.

2.Align heater assembly along centerline of tank having rear end (riser end) of assembly farthest from manhole. Note: On tanks with manhole near end rather than in center heater assembly should be placed on side of manhole farthest from end of tank. See Figure E.

3.Tie the riser(s) with rope or suitable line at a point just below the union on riser(s). Anchor rope to any convenient nearby anchor- ing point. Length of rope should be sufficient to allow riser(s) to be inserted into tank just inside manhole but not below oil level. CAUTION: If oil gets into riser, it will cause failure of the heat- ing element.

4.Carefully turn heater over, feet upward, taking care it is flexed in only the one plane. (See Figure F.) Support must be maintained on riser end of heater to avoid overstressing riser(s) until heater is lowered into tank.

Figure D

Figure E

Figure F

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