Slant/Fin VSL-160C Part A - Manuel (Page 19)

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4. Boiler isolation valves: Field
supplied. Full port ball valves are
required. Failure to use full port ball
valves could result in a restricted
fl ow rate through the boiler.
5. Back fl ow preventer: Field supplied.
Back fl ow preventer valves are
recommended for installation as
shown in Figures 7-6 and 7-7.
Failure to install these valves could
result in a reverse fl ow condition
during pump(s) off cycle.
6. Domestic indirect hot water isolation
valves: Field supplied. Full port ball
valves are required. Failure to use
full port ball valves could result in
a restricted fl ow rate through the
boiler.
7. Anti-scald mixing valve: Field
supplied. An anti-scald mixing valve
is recommended (see Figure 7-6).
It is recommended also when an
indirect water heater is present.
8. Unions: Field supplied.
Recommended for unit
serviceability.
9. Pressure relief valve: Factory
installed. The pressure relief valve
is sized to ASME specifi cations.
10. Indirect water heaters: fi eld
supplied. This boiler may be piped
to an indirect water heater to heat
domestic hot water with the space
heat transfer medium. There are
two options when utilizing an
indirect water heater:
A. The space heating piping will
branch off to fl ow the space heat
transfer medium through a single
wall heat exchanger coil inside
the indirect water heater.
B. The indirect water heater is
connected to the system supply
piping. A pump controlled by the
boiler’s control will regulate the
fl ow of water through the indirect
water heater. The indirect water
heater’s temperature will be
regulated by the boiler’s control.
The boiler is pre-confi gured to
control the operation of the DHW
pump with Domestic Hot Water
Prioritization programming.
CAUTION!!!
It is up to the
installer to ensure the minimum
system fl ow is not less than 5
GPM at any time.
7 - INSTALLATION - Water connections
A = 3/4” pipe extension (not provided)
B = Discharge device open to the
atmosphere (not provided)
C = Condensate discharge pipe
Figure 7-2 Relief valve discharge piping
WARNING!!!
The National
Standard Plumbing Code,
the National Plumbing Code
of Canada and the Uniform
Plumbing Code limit the
pressure of the heat transfer
fl uid to less than the minimum
working pressure of the
potable water system up to
30 psi maximum. Also, the
heat transfer fl uid must be
water or other non-toxic fl uid
having a toxicity of Class 1,
as listed in Clinical Toxicology
of Commercial Products, 5th
Edition
11. Filter: Field supplied. A fi lter or
equivalent multipurpose strainer is
recommended at the return pipe
of the boiler to remove system
particles from older hydronic
systems and protect newer
systems.
7.2.2 - Relief valve
This boiler is equipped with a safety
relief valve set at 30 psi (2 bar) which
must be piped in accordance with
the ANSI/ASME Boiler and Pressure
Vessel Code, Section IV, to prevent
scalding in the event of a discharge.
Pipe the discharge to a drain (See
Figure 7-2). Provide piping that is the
same size as the safety relief valve
outlet
WARNING!!!
Failure
to properly pipe the relief
valve discharge can result in
scalding of individuals and
animals. Never install any type
of valve between the boiler and
the relief valve or an explosion
causing extensive property
damage, severe personal injury
or death may occur!
WARNING!!!
Never block
the outlet of the safety relief
valve or an explosion causing
extensive property damage,
severe personal injury or death
may occur!