GSA
Gas-Fired Steam Boilers –
Boiler Manual
12
Part Number 550-110-738/1012
3 Install piping
continued
Relief valve
During operation, this valve may discharge
large amounts of steam and/or hot water.
Therefore, to reduce the potential for bodily
injury and property damage, a discharge line
MUST be installed that:
• Is connected from the outlet to a safe point
of discharge with no intervening valve.
• Allows complete drainage of both the valve
and the discharge line.
• Is independently supported and securely
anchored so as to avoid applied stress as
possible.
• Terminates freely to atmosphere where any
discharge will be clearly visible and is at no
risk of freezing.
• Is, over its entire length, of a pipe size equal
to or greater than that of the valve outlet.
Use only schedule 40 metal pipe for discharge.
(Do not use schedule 80, extra strong or
double strong pipe or connections.) DO NOT
CAP, PLUG OR OTHERWISE OBSTRUCT
DISCHARGE PIPE OUTLET! If discharge is
piped upward, a condensate drain must be
provided in the elbow below the vertical pipe
to prevent condensate from returning into the
valve. Failure to comply with these instructions
will cause a dangerous spray of hot water and
steam that would cause severe personal injury
or death.
Table 7
Reservoir pipe sizing
Table 8
Boiler feed system sizing
Follow the steps below to avoid potential
severe personal injury, death or substantial
property damage.
• When installing the relief valve, ensure that
all connections, including the valve inlet, are
clean and free from any foreign matter.
• Mount the relief valve only in the vertical
position, directly connected to the tapping
designated in the manual on top of the boiler.
• Use pipe compound sparingly, or tape, on
external threads only.
• Do not use a pipe wrench! Use proper type
and size wrench on wrench pads only.
Install relief valve in tapping on top of boiler. See Table 4,
page 7, for control tapping locations. See the tag attached
to the relief valve for manufacturer’s instructions.
Boiler
model
number
AHRI
gross
output
(pounds
steam
per hour)
Con-
densate
(gallons
per hour)
Minimum condenste receiver
capacity gallons for boiler
steaming times (minutes) of:
(note 1)
Sugguested
feed pump
capacity
(GPM @
15 PSI)
(note 2)
15 min. 30 min. 45 min. 60 min.
GSA-075
63
8
2
4
6
8
0.2
GSA-100
81
10
3
6
9
12
0.3
GSA-125
102
12
4
7
11
14
0.4
GSA-150
122
15
5
9
14
18
0.5
GSA-175
142
17
5
10
15
20
0.6
GSA-200
163
20
6
12
18
24
0.7
GSA-250
203
24
7
14
22
29
0.8
GSA-300
240
29
9
17
26
36
1.0
NOTES:
1. Maximum time to when condensate returns to boiler.
2. If pump capacity exceeds capacity shown, pump can be throttled with globe or
ball valve.
Boiler
model
number
Max. boiler
gross
output
Time from intial steaming to average condensate return
(boiler steaming capacity based on 970 Btu per pound of steam)
15 minutes
20 minutes
30 minutes
MBH
gallons
pipe
length
(feet)
gallons
pipe
length
(feet)
gallons
pipe
length
(feet)
GSA-075/100
75
¾
¾
1
½
1
½
3
2
½
GSA-125/150
125
1 ¼
1 ¼
2
½
2 ¼
Use boiler feed
system
GSA-175
150
1
½
1
½
3
2
½
GSA-200
175
1 ¾
1 ¾
Use boiler feed
system
GSA-250
225
2
½
2
GSA-300
250
2
½
2 ¼
Designed full capacity steaming time of modern boilers is 10 minutes.