Fulton Vertical Electric (FT-N) Thermal Fluid (hot oil) Heater - Manual (Page 74)

Fulton Thermal Corp.*Electric Thermal Fluid Heaters Manual* Version 2010-0423
Page 74
b) Plugged circulation pump strainer basket
1. A plugged strainer will result in a decrease in flow through the heater.
High vacuums developed from plugged strainers can also stress the
seals of the pump causing the pump to fail.
2. A "Pump Suction" gauge is provided on Fulton Thermal skids to help
determine when a strainer needs cleaning. Generally this point is 5-10
psi (10-20 in. Hg).
3. If the strainer is plugged, isolate the strainer and drain being mindful of
the temperature of the thermal fluid. Remove the strainer and clean with
compressed air, high-pressure water or a cleaning solution. Replace and
observe new heater inlet pressure.
c) Failed circulation pump coupling
1. A failed coupling will result in a decreased or no flow condition through
the heater. The coupling can be checked by removing the coupling guard
between the pump and pump motor. The coupling should not be torn or
misshapen. If the coupling needs to be replaced, it will be necessary to
re-align the circulating pump first at ambient temperature and again
when it's at operating temperature.
d) Cavitation of the circulating pump
1. Cavitation occurs when a partial vacuum presents itself at the eye of the
pump impeller due to loss of head or if any low heater flashes to gas at
the impeller. During this time, the pump impeller spins without actually
circulating any thermal fluid.
2. If Fulton Thermal Corporation provided the heater skid, loss of head to
the pump is extremely unlikely with proper fluid level in the tank. The
most common low heater in a thermal piping system is water, which
needs to be boiled out at startup.
3. Once the system has been brought up to full operating temperature,
assuming that the entire system has seen flow, there should be no
further occurrence of low heater contamination apart from heat
exchanger failure.
e) Improper switch setting
1. The Differential Pressure Switch should be set at operating temperature.
The setting should be 2 psi below the minimum differential pressure for
that particular heater model number. If the minimum required pressure is
not known, compare model of heater to chart on page 1-x of this manual.