Weil-McLain EG 5 Series Manual page 19

EG PEG
&
SERIES
Connect piping – steam boilers
Condensate return
Modern steam boilers are designed to steam for less time than
older, larger boilers. When replacing an older steam boiler the
system condensate return time may be longer than the steaming
time. This could cause the following problems:
1. Boilers fitted with an automatic water feed could overfill.
2. Units fitted with only a low water cutoff would shut down
and cycle while waiting for condensate to return.
Following is a simple method for determining whether or not a
reservoir pipe is required to lengthen steaming time for a resi-
dential installation:
1. Disconnect condensate return line at existing boiler.
2. Heat
boiler and allow to steam for 10 minutes. Turn off
3. Measure length of time from when boiler started to steam to
when condensate begins to return through condensate line.
4. Measure length of time from when condensate begins to
return to when it stops returning. Divide this time by 2.
5. Add time measured in step 3 to time calculated in step 4. This
sum is the average time required for condensate to return to
the boiler.
6. If this total time is 10 minutes or less, no reservoir pipe is
needed.
If total time for condensate to return to boiler (from step 5) is
more than 10 minutes, a reservoir pipe (or boiler feed system) is
recommended. See Table 8 and Figure 20 for suggested reservoir
pipe size. Install as shown in Figure 20.
For larger systems (as noted in Table 8), use a boiler feed system
with a condensate tank and feed pump. You will have to install a
low water cutoff/pump control on the boiler to operate the pump.
Use Table 9 to size boiler feed systems. See Figure 5, page 10, for
tapping locations. (The use of a combination condensate tank and
float-controlled condensate return pump is not recommended.)
For most residential installations a reservoir pipe may be all that
is necessary to ensure proper operation.
Reservoir pipe sizing
Boiler Max. Time from initial steaming to average condensate return
boiler
model
ERLOHU VWHDPLQJ FDSDFLW\ EDVHG RQ  %WX SHU SRXQG RI VWHDP
gross
number
output
15 minutes
MBH gallons
75 ¾
EG/PEG-30,-35
EG/PEG-40,-45 125 1 ¼
145 1 ½
EG/PEG-50
EG/PEG-55 167 1 ¾
EG/PEG-65 209 2 ¼
EG-75 247 2 ½
243 2 ½
EGH-85
EGH-95 up Not recommended –– Use boiler feed system if needed
'HVLJQHG IXOO FDSDFLW\ VWHDPLQJ WLPH RI PRGHUQ ERLOHUV LV  PLQXWHV
Part Number 550-142-782/1112
5 EGH 5
SERIES
boiler.
20 minutes 30 minutes
pipe pipe
length length
gallons gallons
IHHW IHHW
¾ 1 ½ 1 ½ 3
1 ¼ 2 ½ 2 ¼
8VH ERLOHU IHHG
V\VWHP
1 ½ 3 2 ½
1 ¾
2 ¼
8VH ERLOHU IHHG
V\VWHP
2 ½
2 ½
-
GAS FIRED BOILERS
(continued)
Recommended piping for parallel-flow systems
with optional reservoir pipe
Boiler feed system sizing
Gross
Boiler
Output
Pounds
Model
Steam
Per
Hour
EG/PEG-30 65
86
EG/PEG-35
108
EG/PEG-40
EG/PEG-45 130
EG/PEG-50 151
174
EG/PEG-55
218
EG/PEG-65
pipe
length
IHHW
EG-75 257
2 ½
EGH-85 253
290
EGH-95
325
EGH-105
EGH-115 361
398
EGH-125
,I SXPS FDSDFLW\ H[FHHGV FDSDFLW\ VKRZQ SXPS FDQ
*
EH WKURWWOHG ZLWK JOREH RU EDOO YDOYH
—
BOILER MANUAL
Minimum Condensate
Receiver Capacity (Gal.)
Gallons
Minutes of boiler
Conden-
operation:
sate
Per
15 30 45
Hour
7 ½ 2 5 7
10 3 7 10
12 ½ 4 8 12
15 5 10 15
17 ½ 6 12 17
20 7 13 20
25 8 17 25
29 ½ 10 20 29
29 10 19 29
33 ½ 11 22 33
37 ½ 12 25 37
41 ½ 14 28 41
46 15 31 45
Recom-
mended
Maximum
Feed
Pump
Capacity
60
*
GPM
10 0.3
13 0.3
17 0.4
20 0.5
23 0.6
27 0.7
33 0.8
39 1.0
39 1.0
45 1.1
50 1.3
55 1.4
61 1.5
19