MIL-T-13291 Tank, Hot-Dip, Directly And Indirectly Heated

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MIL-T-13291F

3.3.4 Surfaces. All surfaces shall be clean and free of sand, dirt, fins,

sprues, flash, scale, flux, and other harmful or extraneous materials.

All

edges shall be either rounded or beveled unl ess sharpness is required to

perform a necessary function. Except as otherwise specified herein, the con-

dition and finish of all surfaces shall be in accordance with the manufac-

turer's commercial practice.

3.3.5 Painting. Unless otherwise specified (see 6.2.1), the hot-dip tank

shall be painted in accordance with the manufacturer's commercial practice.

3.3.6 Threads. All threaded parts used on the hot-dip tank and its related

attachments and accessories shall conform to FED-STD-H28 and the applicable

"Detailed Standard" section referenced therein.

3.4 Electrical requirements. The hot-dip tanks shall be furnished complete

with all electric motors, controls, relays, signal lights and switches, pre-

wired where possible for operation when connected to source of power.

All

electrical equipment and the installation thereof shall be in compliance with

ANSI/NEMA ICS 1 and enclosures shall be in compliance with ANSI/NEMA ICS 6,

Type 12.

Heating elements not specifically covered in the standard shall be

covered and insulated to prevent contact with flammable liquids and vapors.

3.4.1 Power supply. Voltage and current characteristics of the tanks shall

be as specified (see 6.2.1).

3.4.2 Electrical connections. Connections of conductors and terminal parts

shall be of the screw, pressure, or solder type.

When soldered connections

are used, the connections shall be mechanically secured before soldering.

Rosin base fluxes only shall be used in soldering operations.

Connections to

screw type terminals shall be mechanically secured with means to prevent loss

of tightness.

3.4.3 Dielectric strength. All conducting components of the electrical

circuit shall be capable of withstanding without damage twice the rated

voltage plus 1000 volts root mean square (rms) between the circuit components

and the dip-tank cabinet for a period of 1 minute at a frequency not less than

the rated frequency of the power supply.

3.5 Performance.

3.5.1 Class A. Class A tanks with dip compartment capacities up to 10

cubic feet, when filled to 80 percent of capacity with a heat-transfer fluid,

shall be capable of raising the temperature of the fluid with the cover

closed, from 70� F �5� F to not less than 210� F in not more than 3 hours and

tanks with capacities from 10 to 20 cubic feet in not more than 4 hours. The

fluid used for the heating requirements shall have an average specific heat

content of not less than 0.50 Btu/lb. Beating requirements of tanks with dip-

ping compartment capacities greater than 20 cubic feet shall be as specified

(see 6.2.1).