9
SYSTEM PIPING
Consider near boiler piping as part of the boiler for proper
water level control and to produce dry steam.
Correct near boiler piping is crucial to proper operation of
boiler and heating system.
Follow these recommendations carefully:
1.
Single riser installations are not recommended for
boiler sizes 5-9 sections. Use double riser piping for
boiler sizes 5-9 sections.
2.
Place boiler in selected location as near chimney as
possible.
3.
Install safety valve. Figure 2 and Warning on Page 8.
•
Install union, if used, close to safety valve outlet.
•
Install elbows close to safety valve outlet and
downstream of union (if used).
4.
Boiler is equipped with two 2½" supply connections
and two 2½" return connections, one each on both left
and right sides of boiler. Plug unused connections with
furnished 2½" plug (furnished).
5.
When using both supply tappings to pipe system as
shown in Figure 4, Page 11.
•
Fit headers with header offsets, swing joints, or equip
with expansion joints, so thermal expansion and
contraction of header does not damage boiler. Do not
weld headers.
•
Place system takeoffs from header between equalizer
and riser to header nearest equalizer. System takeoffs
must never be between two risers. If steam main goes
in two directions, place two takeoffs from header, one
for each main.
6.
System takeoffs from the header must never be
bullheaded. If the steam main goes in two directions,
there must be two takeoffs from
the header, one for each
main.
7.
All boilers in gravity return systems
shall
be equipped
with a Hartford Loop as shown in Figures 3 & 4.
8.
When piping the vertical risers from the boiler to the
header, the bottom of the header must be a minimum
of 24 inches above the water level line on the right side
of the boiler.
9.
Steam riser(s) and header shall be 2½” pipe size.
10.
Equalizer line shall be minimum 1½” pipe size.
11.
The near boiler piping shall include a 2½” tee with a
plug located on the supply line as shown for skimming
(i.e. surface blowdown).
12.
The near boiler piping shall include a 1-1/2 ball valve
in the return piping as shown for bottom blowdown and
draining.
13.
For gravity return systems, the bottom of the lowest
steam carrying pipe, be it a dry return, or the end of the
steam main, must be at least 28” above the normal water
level line on the right side of the boiler. This is known as
“Dimension A.”
14.
For pumped return systems, follow the condensate
pump or boiler feed pump manufacturer’s instructions
for proper installation and hookup.
15.
In connecting the cold water supply to the water inlet
valve, make sure that a clean water supply is available.
When the water supply is from a well or pump, a sand
strainer should be installed before the pump.
For Use With Cooling Units
Install boiler, when used in connection with refrigeration
system, so chilled medium is piped in parallel with boiler
with appropriate valves to prevent chilled medium from
entering the boiler. See Figure 5 page 11.
PN 14683003 Rev. O [10/01/2021]
Installation
Design and install boiler and system piping to prevent
oxygen contamination of boiler water.
Sources of oxygen contamination are system leaks
requiring addition of makeup water, fittings, and oxygen
permeable materials in distribution system.
Eliminate oxygen contamination by repairing system leaks,
repair fittings, use non-permeable materials in distribution
system, and eliminate open tanks in the system, or isolate
boiler from system with heat exchanger.
Water Quality
• Do not use softened water in steam boilers. Accelerated
boiler corrosion will result.
• Consult local water treatment companies for unusually
hard water area (above 7 grains hardness) or low
pH water conditions. Boiler water pH of 7 to 8.5 is
manufacturer recommended.
