WATLOW IND.
WATROD Circulation Heater Installation & Maintenance Manual
I&M NUMBER: 316-42-5-1
Page: 3
Date: 6/11/2008
Rev: 2.00
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WATLOW IND.n # 6 INDUSTRIAL LOOP RD. n HANNIBAL MO, 63401n PHONE 573-221-2816 n FAX 573-221-3723
INLET
OUTLET
OUTLET
INLET
INLET
OUTLET
OUTLET
INLET
AIR / GAS APPLICATION
LIQUID APPLICATION
Figure # 1
Figure # 2
NPSH
PUMP
NPSH
PUMP
INCORRECT HEATER POSITION - HEATER ABOVE NPSH
CORRECT HEATER POSITION - HEATER BELOW NPSH
Figure # 3
When installing piping connections, care should be taken to avoid supporting the tank by the nozzles.
Mounting blocks are provided to help prevent this. Provisions for thermal expansion and contraction
should be considered, slotted bolt holes in one of the mating mounting pads would do adequately.
Installation of an isolation valve and pressure relief valve is recommended but not provided. Rating of
valves should not exceed the ANSI class 150 flange rating. Two 1/2" FNPT couplings are provided for
drainage and installation of valves.
DANGER: HAZARD OF FIRE.
Electric heaters are capable of developing high temperatures so extreme
care should be taken to locate heaters in safe environments. Mounting heaters in atmospheres
containing combustible gases and vapors should be avoided. According to article 501 of the NEC, the
maximum surface temperature of the heater shall not exceed 80 % of the auto-ignition of the surrounding
