Fulton Hopkins (HPN) Horizontal Coil Thermal Fluid (hot oil) Heater - Manual (Page 67)

Questions? Call (315) 298-5121 or visit us online at www.fulton.com
SECTION 4
HPN-IOM-2014-0416
MAINTENANCE
4-7
!
WARNING
All information in this manual is for
reference and guidance purposes,
and does not substitute for required
professional training, conduct,
and strict adherence to applicable
jurisdictional/professional codes and
regulations.
At no time should the high inlet
pressure switch be set above the safety
relief valve set pressure.
4
CAUTION
All maintenance procedures should
be completed by trained personnel.
Appropriate training and instructions
are available from the Fulton Service
Department at (315) 298-5121 or your
local Fulton Thermal Representative.
 Diff erential Pressure Switch
With the circulating pump running, observe the diff erence in pressure between
the heater outlet gauge and the heater inlet gauge. Remove the top cover of the
diff erential pressure switch. Note the original setting of the switch. The setpoint
should be 2 - 3 psi below the published diff erential pressure of the heater (this
will vary by heater model, refer to Product Data Submittals). See Figure 20.
FIGURE 20 - DIFFERENTIAL PRESSURE SWITCH
 Low Inlet Pressure Switch
Slowly close the valve on outlet of main circulating pump observing heater inlet
pressure gauge. Note the pressure at which the switch trips. The setpoint should
be 10 psi lower than the heater inlet pressure when the system is at operating
temperature (or 50 psig, whichever is less).
 High Inlet Pressure Switch
Note the original setting of the switch and turn adjustment screw
counterclockwise while observing heater inlet pressure gauge until switch trips.
The pointer on the switch should be within 2 psi of the observed pressure.
The setpoint should be 25 psi above the heater inlet pressure when the system
is cold; however, at no time should the switch be set above the safety relief valve
set pressure.
 High Outlet Pressure Switch
Note the original setting of the switch and turn adjustment screw
counterclockwise while observing heater outlet pressure gauge until switch trips.
The setpoint should be 25 psi higher than the heater outlet pressure when the
system is at operating temperature and pressure; however, at no time should the
switch be set above the safety relief valve set pressure.