Fulton Hopkins (HPN) Horizontal Coil Thermal Fluid (hot oil) Heater - Manual (Page 24)

© The Fulton Companies 2014
INSTALLATION
HPN-IOM-2014-0416
SECTION 2
2-18
 Sizing The Expansion Tank For The System
Expansion tank capacity is the total volume of the tank
(see Figures 8 and 9). It is necessary to have some air space
available at the top of the tank to avoid spillage or overfl ow.
At initial fi ll (for system volume calculations) the deaerator
and cold seal sections must be fi lled completely and the
expansion section must be fi lled to a level of 4 inches (102
mm) to “make” the liquid level switch.
The volume between the initial fi ll level and the safe “full” level
is the amount available for expansion. That volume is used to
decide which tank is suitable for the system expansion.
 SIZING EXAMPLE
A system contains 175 gallons, including the heater, but not
the tank. You select the FT-200-L, so you add 25 gallons to 175
for a total of 200 gallons.
You look up the expansion rate for the thermal fl uid.
(Assuming it is 25%), 200 gal. x 1.25 = 250 gallons, 250-200 =
50 gallon expansion.
The FT-200-L has only 46 gallons available for expansion, so
the correct selection is the FT-500-L.
Adhere to the following for installation:
1. Install tank in accordance with Fulton’s specifi cations.
2. Unless the system is pressurized, the inlet to the
deaerator section must be higher than or equal to the
highest point in the system to prevent pockets of air
from collecting in system piping.
3. Take into account the head required at the circulation
pump suction inlet to avoid the possibility of pump
cavitation.
4. In systems operating close to maximum fl uid
temperature, ensure the tank is elevated enough,
possibly well above the highest point in the system, to
prevent pump cavitation by increasing the static head.
An inert pressurizing blanket may be considered as an
alternative. See Pressurized Systems section of this
manual.
5. Provide supports for tank mounting. These should be
suited for supporting the tank by the side rails. The
eyelets fi tted to the tank are for lifting only.
 Two-Pipe Expansion Tank
An alternate confi guration is the 2-pipe expansion tank. This
may be used at start-up to remove air and water from the
system, and then valved appropriately during operation to
provide expansion capacity for the system.
 Pressurized Systems
Nitrogen pressurization may be used if the total system
content is very large, or in a system operating near or above
the vapor pressure of the fl uid employed, or if the inlet of the
DA tank is not the highest point in the piping system, or at
any time to further protect the fl uid from oxidation.
In conjunction with this system, adhere to the following:
1. An automatic venting device must be fi tted to the
system expansion tank. Consult Fulton for further
details.
2. The location for the liquid level switch (Figure 10) is a
2-1/2” NPT connection on the same end of the tank as
the inlet. The liquid level switch is supplied and shipped
with the unit, and must be installed by the customer and
then wired to the control panel.
3. If the tank is located outdoors, nitrogen is required.
 Vent Connections
Adhere to the following for vent connections:
1. Make vent connection in a manner that will prevent
penetration of water or foreign bodies into the tank.
This connection must always terminate in a safe, well
ventilated area and has to be free of obstruction, open
to atmosphere, and arranged in such a manner that,
in the event of discharge from the system, thermal
fl uid could drain into a catch tank without danger to
personnel or property.
2. Make the vent run the same size as the tank outlet. It
should run pitch down from the outlet of the tank to
the catch tank.
3. If nitrogen is used on the system, the vent can be
reduced to 2” (51 mm) and should be piped with a
positive closing valve at the catch tank.
4. Ensure the connection between the tank outlet and the
horizontal pump inlet is as close to a vertical drop as
possible. It should have the minimum bends and length
of pipe.
5. Ensure the inlet to the deaerator is higher than or equal
to the highest point in the system, or a pressurized