Smith Cast Iron Boilers 28HE - Manual (Page 15)

Page 15 SERIES 28HE BOILER INSTALLATION AND OPERATION INSTRUCTIONS
Figure 16 - Relief & Safely Valve Piping
WATER BOILER PIPING
The supply and return connections should be sized
to suit the system, see Figures 14, 15, 17, 18 and Tables
5 & 6. Do not pipe the supply from the bottom port or
the return to the top port, the boiler will not work
properly. Typical water boiler piping arrangements are
shown in Figures 19 & 20. Swing joints should be used.
Install 3" nipples into the two 3" NPT tappings in the
front section and cap them.
NOTE: See CLEANING OF WATER BOILERS on page
18 before proceeding!
Supply Piping
Install a reducing bushing in the 6" NPT tapping in the
front section to obtain the correct supply pipe size,
Figure 14 and Tables 5 & 6.
Table 6 - Water Boiler Piping
Boiler Size
Return Size Supply Size
# Sections NPT NPT
4 & 5 3 3
6 through 9 4 4
10 through 18 5 5
Note: Sizes based on 20 ° F, 11.1 ° C, ∆ T for the system.
Return Piping 4 through 9 Section Boilers
Install 3" x 4" NPT bushings in the two 4" NPT tappings
at the bottom of the back section. Install two 3" NPT
x 6" nipples per Figure 17. Assemble the rest of the
return yoke as shown in Figure 17.
Table 7- Boiler Water Content
Boiler Model Water Boilers Steam Boilers
Gallons Liters Gallons Liters
28HE-4 123 466 104 394
28HE-5 150 568 126 477
28HE-6 177 670 148 560
28HE-7 204 772 170 644
28HE-8 231 875 192 727
28HE-9 258 977 214 810
28HE-10 285 1079 236 893
28HE-11 312 1181 258 977
28HE-12 339 1283 280 1060
28HE-13 366 1386 302 1143
28HE-14 392 1484 324 1227
28HE-15 419 1586 346 1310
28HE-16 446 1689 368 1393
28HE-17 473 1791 399 1511
28HE-18 500 1893 412 1560
Return Piping 10 Through 18 Section Boilers
Install two 4" NPT x 6" nipples per Figure 17. Assemble
the rest of the return yoke as shown in Figure 17.
Control Installation
Locate the temperature & pressure gage, low water
cutoff, high limit and operating controls per Figures 14
& 18. Optional controls must be installed in accordance
with the control manufacturers instructions and Figures
14 & 18.
Note: The front jacket panel MUST be installed
before any controls are attached to the front boiler
section!
CAUTION: The controls must be mounted in the
correct location and according to the control
manufacturer’s instructions or the boiler may not
function properly!
Water Column Piping
A variety of water level controls are available for the
28HE. The water column piping needed to properly
mount each control is available from Smith. Figure 18
shows a typical water column piping arrangement. The
1" NPT x 7 1/2" nipple is always installed in the lower
water column tapping, Figures 14 & 18 and Table 5.