Bell & Gossett V1000001B PT Diaphragm Non-Code Expansion Tanks - Manual (Page 4)

SERVICE INSTRUCTIONS
1. Check the expansion tank periodically for signs of
external leakage or corrosion. If any is found, the tank
must be replaced.
2. If a HVAC system is shut down for long periods or
emptied for any reason, it is necessary to follow the fol-
lowing procedure:
a. Fill system.
b. Vent air from system (see system venting and purging).
c. Bring system up to maximum operating temperature.
Before fi lling and starting the operation of a HVAC
system, a properly applied and sized pressure relief valve
must be installed and in good operating order.
During fi lling and start-up after servicing, the system
pressure should be closely monitored to ensure the
pressure does not exceed the pressure relief valve rating.
Consult the applicable pressure relief valve
manufacturer’s instructions as necessary.
3. If the system pressure is too high:
a. Check gauge calibration.
b. Check to see if expansion tank has lost its air charge.
NOTE: To check the expansion tank air pressure with a tire
gauge, either:
1. Disconnect the expansion tank from the system or,
2. Draw off system water until boiler pressure reads zero
or isolate the expansion tank from the system in domestic
water systems, and bleed pressure from the system. All
drains must be kept open during servicing of the
expansion tank. (Expansion tank must be empty of
expanded system water.)
3. Then check tank pressure with tire gauge.
c. Check for faulty fi ll valve operation. First, close manual
shutoff located before the fi ll-valve; then, draw system
pressure down to pre-set pressure (see TABLE 1) open
shut-off valve and observe system for pressure build-up
several hours later. If pressure build up beyond set
pressure is found, replace fi ll valve following the
manufacturer’s instruction.
d. Check for service water entering system from any other
source such as a defective tankless heater or indirect fi red
water storage tank. Use same procedure as above after
shutting off possible water source. Replace defective
device if found following manufacturer’s instruction.
WARNING: System fl uid under pressure
and/or at high temperatures can be very
hazardous. Before servicing, reduce system
pressure to zero or isolate the vessel from
the system. Allow system to cool below 100 o F and
above 35 o F. Failure to follow this instruction may result
in serious personal injury and /or property damage.
4. If pressure relief valve drips water:
a. First, check system pressure. If too high, follow steps
3.a., b., c., and d. above.
b. If pressure relief valve continues to drip water, even at
reduced pressure, fl ush relief valve by quickly raising lever
several times. If drip continues, replace relief valve
following manufacturer’s instruction.
c. If multiple expansion tanks are installed in the system,
check pressure of each for possible air leaks. Be sure air
valve caps are on tight. Multiple tanks should be in the
same location.
WARNING: Improper use of air charging
valve during venting of air pressure from
tank will create a hazardous condition due
to the escape of high velocity gas and/or
liquid. Depress the center valve core stem, as with a tire
valve to slowly vent off gas pressure. Do not remove
the valve core until pressure in expansion tank has
reached zero. Failure to follow these instructions could
result in serious personal injury or death and property
damage.
WARNING: Signs of leakage or corrosion are
indications the tank may have failed.
Periodically check the expansion tank for
signs of external leakage or corrosion. If
found, the tank must be replaced. Failure to follow
these instructions may result in serious personal injury
or death and property damage.
Xylem Inc.
8200 N. Austin Avenue
Morton Grove, Illinois 60053
Phone: (847) 966-3700
Fax: (847) 965-8379
www.xyleminc.com/brands/bellgossett
Bell & Gossett is a trademark of Xylem Inc. or one of its subsidiaries.
© 2012 Xylem Inc. V1000001B May 2012