3. This boiler is equipped with two 2-1/2-in. supply connections and two 2-1/2-in. return connections, 1 each on both the left and right sides
of boiler. Unused connections must be plugged with factory-supplied 2-1/2-in. plugs.
4. Recommended near boiler piping for gravity return systems is shown in Fig. 3. This configuration uses 1 supply and 1 return tapping. This
setup can be used on any size boiler in this series. The supply and return connections may be piped both into the same side (either left or
right) or 1 into each side of boiler.
5. For installers choosing to use both supply tappings, refer to Fig. 4 for CORRECT way to pipe system. Fig. 5 shows WRONG way to pipe
a header with 2 risers.
a. Headers must be fitted with header offsets or swing joints, or be equipped with expansion joints, so that thermal expansion and
contraction of header will not damage boiler. Headers shall not be welded.
b. System takeoffs from header must be between equalizer and riser to header nearest equalizer. System takeoffs must never be between
2 risers.
6. System takeoffs from header must never be bullheaded. If steam main goes in 2 directions, there must be 2 takeoffs from header, 1 for each
main.
7. All boilers in gravity return systems MUST be equipped with a Hartford Loop as shown in Fig. 4 and 5.
8. When piping vertical risers from boiler to header, bottom of header must be a minimum of 24 in. above water level line on right side of
boiler.
9. Steam riser(s) and header shall be 2-1/2-in. pipe size.
10. Equalizer line shall be a minimum 1-1/2-in. pipe size.
11. The near boiler piping shall include a 2-1/2-in. tee with a plug located on supply line for skimming (surface blowdown). (See Fig. 3 or 4.)
12. The near boiler piping shall include a 1-1/2-in. ball valve in return piping for bottom blowdown and draining. (See Fig. 3 or 4.)
13. For gravity return systems, bottom of lowest steam carrying pipe, be it dry return or end of steam main, must be at least 28 in. above normal
water level line on right side of boiler. This is known as "Dimension A."
Fig. 3—Recommended Near Boiler Piping Using 1 Supply Tapping
A95493
FLUE COLLAR
POP SAFETY VALVE
STEAM
MAINS
MAIN VENT
REDUCING ELL
POINTING DOWN
WATER FEED
GATE VALVE
(NOT FURNISED)
DRY
RETURN MAIN
WET RETURN
DRAIN VALVE (FURNISHED)
FOR FLUSHING SYSTEM
CLOSE
NIPPLE
15
″
MIN.
6
″
28
″
MIN. - DIMENSION A
15
″
MIN.
6
″
TO 10
″
24
″
MIN.
1
1
/
2
″
MIN.
PIPE SIZE
1
1
/
2
″
FULL PORT BALL VALVE
FOR BOTTOM BLOW DOWN
AND DRAINING BOILER &
SYSTEM (NOT FURNISHED)
WATER LINE
24
″
2
1
/
2
″
MIN. TEE
WITH PLUG
FOR SKIMMING
PIPE FULL SIZE SAME
AS BOILER TAPPING
(2 1/2
″
)
—7—
