Weil-McLain GV90+ - Expansion tank

Part number 550-142-903/1016
13
&IGURE Relief valve installation guidelines
GV90+ Series 2 GAS-FIRED WATER BOILER — Boiler Manual
Install water piping (continued)
4OAVOIDWATERDAMAGEORSCALDINGDUE
TORELIEFVALVEOPERATIONASPERLOCAL
ORSTATECODES
:
Discharge line must be connected to re-
lief valve outlet and run to a safe place of
disposal. Terminate the discharge line in
a manner that will prevent possibility of
severe burns or property damage should
the valve discharge.
Discharge line must be as short as pos-
sible and be the same size as the valve
discharge connection throughout its
entire length.
Discharge line must pitch downward
from the valve and terminate at least
6” above the floor drain where any dis-
charge will be clearly visible.
The discharge line shall terminate plain,
not threaded, with a material serviceable
for temperatures of 375°F or greater.
Do not pipe the discharge to any place
where freezing could occur.
No shutoff valve shall be installed be-
tween the relief valve and boiler, or in
the discharge line. Do not plug or place
any obstruction in the discharge line.
Test the operation of the valve after fill-
ing and pressurizing system by lifting
the lever. Make sure the valve discharges
freely. If the valve fails to operate cor-
rectly, replace it with a new relief valve.
Failure to comply with the above guide-
lines could result in failure of the relief
valve to operate, resulting in possibility
of severe personal injury, death or sub-
stantial property damage.
Expansion tank
Figure 14, page 14 and Figure 15, page 14 show typical installation
of the expansion tank. Always locate the air separator and expansion
tank as shown in the suggested piping drawings, beginning with Fig-
ure 17, page 16.
Ensure that the expansion tank size will handle boiler and system water
volume and temperature. See tank manufacturer’s instructions and rat-
ings for details. Additional tanks may be added to the system if needed
to handle the expansion. These tanks may be installed by connecting
to tees in the system piping.
5NDERSIZEDEXPANSIONTANKS cause system water to be
lost from the relief valve and makeup water to be added
through the fill valve. Eventual section failure can result.
Always locate the
COLDWATERlLLCONNECTION at the ex-
pansion tank. Never locate this elsewhere in the system.
$IAPHRAGMORBLADDERTYPETANK
Refer to Figure 14, page 14 for suggested piping when using a dia-
phragm- or bladder-type expansion tank.
$IAPHRAGMORBLADDERTYPEEXPANSIONTANK — Con-
trol
lLLPRESSURE with the tank air charge pressure. Al-
ways check pressure and charge tank with tank removed
from system
to be sure reading is accurate. Boiler relief
valve is set for 30 PSIG. Operating pressure of system,
after temperature expansion above cold fill pressure,
should not exceed 24 PSIG to avoid weeping of relief
valve.
Install an
AUTOMATICAIRVENT on top of the air separator, per separator
manufacturer’s instructions.
#LOSEDTYPEEXPANSIONTANK
Figure 15, page 14 shows suggested piping when using a closed-type
expansion tank, in which the air is directly in contact with tank water.
Connect piping (½” or ¾”) from the air separator top outlet to the
tank fitting. Slope any horizontal piping a minimum of 1 inch per
5 feet of horizontal pipe.
Always use a
TANKlTTING, such as the B&G Tank-trol or Taco Taco-Trol
(shown). The fitting reduces gravity flow of water in the piping to the
tank, avoids air bubbling through the tank water, and provides the
proper fill height in the tank.
#ORRECTALL LEAKS in the system or tank piping. Leaks
allow air to escape from the system and will cause water-
logging of the tank. This will result in water loss through
the boiler relief valve due to over-pressurization.
.%6%2use an automatic air vent in a system equipped
with a closed-type expansion tank. The air removed from
the system will cause water-logging of the expansion tank.
#LOSEDTYPE EXPANSION TANK — Follow tank manu-
facturer’s instructions for
lLLINGTHETANK. Typical tank
sizing provides for approximately 12 PSIG when the tank
is filled to the normal level and system water is cold. Note
that boiler relief valve is set for 30 PSIG. Operating pres-
sure of system, after temperature expansion above cold
fill pressure, should not exceed 24 PSIG to avoid weeping
of relief valve.