MODEL STX
Packaged Semi-Instantaneous
Steam Fired Water Heater
Shell and Tube Style Heater
Features
■
Reliable
� Only high grade materials used in
construction to ensure long operating life
� Heat exchange pressure vessel
constructed from 90/10 Copper-Nickel
for long service life
� Heavy duty construction withstands
demanding commercial/industrial use
■
Packaged System
� Factory selected and sized steam control
valve simplifies installation and ensures
reliable operation
� All steam operating controls are factory
sized and selected to ensure reliable
operation
■
Versatile
� Full range of styles, sizes, and optional
features to meet your exact heating
needs
Applications
■
■
■
■
Schools
Office Buildings
Sports Complexes
Hotels
■
■
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Industrial Facilities
Nursing Homes
Hospitals
Model STX
Semi-Instantaneous Type
The Model STX is equipped with all operating
controls and ready for immediate installation
ASME
U
A Heavy Steam Fired Semi-Instantaneous Water Heater
Whether you are heating potable water in a commercial
The Model STX is a fully packaged semi-instantaneous
building or process water in an industrial application,
steam fired water heater which utilizes steam for
you can select a Hubbell STX model to do the job.
heating potable water. The entire package is designed
When you specify and install a Hubbell water heater,
to be a reliable and long lasting source for hot water.
you will be provided with a quality product that is a long
Each component is carefully selected to ensure high
performance in even the most demanding application. lasting and trouble free source for hot water.
A Packaged Water Heater Ready For Installation
Model STX Semi Instantaneous Standard Equipment
Vessel Construction
Heating Coil
1. Solid 90/10 vessel designed and built in strict
accordance with the ASME Code Section VIII
and stamped, certified, and registered with the
National Board of Boiler and Pressure Vessel
Inspectors
2. Designed for 150 psi working pressure and
hydrostatically tested
Steam
Water Operating Controls
1. Steam operating controls are factory selected, sized,
piped and tested to ensure reliable operation
2. All steam components are factory plumbed with
schedule 40 black iron pipe and ready for steam
and condensate connections
3. High quality cast iron pilot operated steam control
valve modulates the flow of steam through the
heating coil to provide accurate water temperature
control
4. Cast iron Y strainer with 20 Mesh screen protects
the steam controls and coil from dirt and debris in
the steam supply
5. Thermostatic drip trap removes condensate from
the steam supply line
6. Heavy duty cast iron float and thermostatic main
condensate trap for optimum efficiency
7. All bronze integral circulating pump
8. Direct mounted steam and domestic water
1. Factory sized and installed copper heating
2.
3.
4.
5.
coil with a generously sized heating surface
designed to ensure reliable operation
U-Tube heating coil constructed from single
wall copper tubing designed for a maximum
working pressure of 150 psi
Heavy duty fabricated steel head with
threaded NPT inlet and outlet connections
All wetted parts are non-ferrous for maximum
longevity
Non-Ferrous tube sheet
General
1. Heavy duty 3" thick fiberglass insulation for
2.
3.
4.
5.
maximum operating efficiency and minimal
stand-by heat loss
Heavy gauge painted galvanized steel
protective outer jacket
Heavy duty integrally welded steel supports
and base for floor mounting
Full five (5) year Non Pro-Rated pressure
vessel and a one (1) year component warranty
ASME rated combination T&P relief valve set
at the tank working pressure and 210oF
temperature and pressure gauges
9. High limit Single solenoid safety system closes
the steam supply to the heating coil should the
water temperature in the tank reach the hi-limit
set point. Requires 120 volt 5 amp electrical service
Optional Equipment
NOTE: Other optional features are available, please consult factory if required.
Vessel
1. Alternate vessel construction:
Stainless Steel Type 304 or 316L
2. Alternate working pressure:
Please specify
Heating Coil
3. Double wall tubing with a leak detection
port
4. Alternate tubing material please specify:
(Stainless Steel, 90/10 Copper-Nickel,
Admiralty)
5. Fabricated head constructed from:
(Stainless Steel, Copper Alloy)
General
6. Type 304 stainless steel protective outer
jacket, please specify if painted
Operating Controls
7. A double solenoid safety system dumps
over heated water in the vessel to drain
in addition to closing the steam supply to
the heating coil. Requires 120 volt 5 amp
electrical service
8. Electric or Pneumatic operated steam
control valve
9. Electric Control package for integration
with Energy Management Software (EMS)
and Building Automation Software (BAS).
MODBUS communication to monitor the
heater via RS-232 or RS-485
2
Model STX Vertical Dimensions (inches)
Model No. Based on 100oF∆ T Recovery Rate (40-140˚F)
Base Model
Recovery
Rating
(GPH)
40-140°F
BTU/Hr
STXCN600
600
500,000
STXCN900
900
750,000
STXCN1200
1200
1,000,000
STXCN1500
1500
1,250,000
STXCN1800
1800
1,500,000
STXCN2400
2400
2,000,000
STXCN3000
3000
2,500,000
STXCN3600
3600
3,000,000
STXCN4200
4200
3,500,000
STXCN4800
4800
4,000,000
STXCN6000
6000
5,000,000
STXCN7500
7500
6,250,000
STXCN9000
9000
7,500,000
STXCN10500
10,500
8,750,000
Steam
Supply
Pressure
(psi)
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
5
15
25
50
75
Vertical Model STX Overall Dimensions (inches)
Single Wall
C
D
A
B
99
87
87
87
99
88
99
99
87
87
88
76
76
87
87
76
88
76
99
87
76
76
88
76
99
77
76
76
88
88
77
76
76
76
88
77
77
76
76
76
78
77
77
76
76
78
77
77
76
76
84
78
77
77
76
87
78
78
77
77
46
40
40
40
46
40
46
46
40
40
40
34
34
40
40
35
40
34
46
40
35
35
40
34
46
35
35
35
40
40
35
35
35
35
40
35
35
35
35
35
36
35
35
35
35
36
35
35
35
35
37
36
35
35
35
38
36
36
35
35
35
29
29
29
36
29
35
35
29
29
29
23
23
29
29
22
29
23
35
29
22
22
29
23
35
22
22
22
29
29
22
22
22
22
29
22
22
22
22
22
21
22
22
22
22
21
22
22
22
22
27
21
22
22
22
27
21
21
22
22
84
78
78
77
37
36
36
35
87
84
78
77
38
37
36
35
Weight
(Lbs)
Double Wall
B
C
D
E
100
100
88
88
88
88
100
100
88
88
88
88
100
100
88
100
88
88
100
100
89
88
88
88
100
89
100
88
88
88
78
89
89
88
88
90
89
89
100
88
90
78
89
89
100
96
90
78
89
100
87
90
78
89
89
46
46
40
40
40
41
46
46
40
40
41
41
46
46
40
47
41
41
46
46
41
41
41
41
46
41
47
41
41
41
36
41
41
41
41
42
41
41
47
41
42
36
41
41
47
43
42
36
41
47
38
42
36
41
41
35
35
29
29
29
28
35
35
29
29
28
28
35
35
29
34
28
28
35
35
28
28
28
28
35
28
34
28
28
28
21
28
28
28
28
27
28
28
34
28
27
21
28
28
34
33
27
21
28
34
27
27
21
28
28
13
13
13
13
13
15
13
13
13
13
15
15
13
13
13
15
15
15
13
13
17
15
15
15
13
17
15
15
15
15
19
17
17
15
15
19
17
17
15
15
19
19
17
17
15
20
19
19
17
15
22
19
19
17
17
19
19
19
19
19
21
19
19
19
19
21
21
19
19
19
21
21
21
19
19
23
21
21
21
19
23
21
21
21
21
25
23
23
21
21
25
23
23
21
21
25
25
23
23
21
27
25
25
23
21
31
25
25
23
23
87
84
90
89
38
37
42
41
27
27
27
28
22
20
19
17
31
27
25
23
610
585
585
585
560
655
610
610
585
585
655
615
615
585
585
770
655
615
610
585
770
770
655
615
610
985
770
770
655
655
985
770
770
770
655
985
985
770
770
770
1130
985
985
770
770
1130
985
985
770
770
1480
1130
985
985
770
1610
1130
1130
985
985
27
25
25
23
99
99
90
90
44
44
42
42
33
33
27
27
22
22
19
19
31
31
25
25
1480
1130
1130
985
31
27
25
23
99
96
90
44
43
42
33
33
27
22
20
19
31
27
25
1610
1480
1130
985
E
A
12
12
12
12
11
13
12
12
12
12
13
13
13
13
13
15
13
13
12
12
15
15
13
13
12
17
15
15
13
13
17
15
15
15
13
17
17
15
15
15
19
17
17
15
15
19
17
17
15
15
20
19
17
17
15
22
19
19
17
17
18
18
18
18
17
19
18
18
18
18
19
19
19
18
18
21
19
19
18
18
21
21
19
19
18
23
21
21
19
19
23
21
21
21
19
23
23
21
21
21
25
23
23
21
21
25
23
23
21
21
27
25
23
23
21
31
25
25
23
23
27
21
21
22
20
19
19
17
27
27
21
22
22
20
19
17
Note: All dimensions are approximate and subject to change. Please reference the submittal drawing for actual dimensions.
Please consult factory for recovery ratings for steam pressures not shown.
3
Vertical Semi-Instantaneous Steam Fired
Outline Dimensions -
Model STX (Vertical)
D
Hot Water Outlet
Protective Jacket
T&P Relief Valve
Thermometer
Temperature Controller
Hi-Limit Thermostat
Pump Switch
Hi-Limit
Solenoid Valve
Insulation
Drain
Recirculation Pump
Pressure Gauge
Cold Water Inlet
Control Valve
Steam Inlet
A
Inlet Strainer
Trap Strainer
B
C
Drip Trap
Main Trap
Condensate Outlet
E
Horizontal Semi-Instantaneous Steam Fired
Product Overview -
Model STXH (Horizontal)
Note: Please contact factory for horizontal dimensions
Control Valve
Temperature
Controller
T&P Relief Valve
Hi-Limit Thermostat
Pump Switch
Pressure Gauge
Drain
Hi-Limit
Solenoid Valve
Withdrawal Space
Hot Water
Outlet
Insulation
Thermometer
Protective
Jacket
Cold Water
Inlet
Recirculation Pump
TOP VIEW
END VIEW
4
Redundant System
Skid Package Option
5
Model Number Designation
STX Model Number Designation
CN
—
■Step2
■Step1
■Step4
■Step3
Model:
VesselType:
STX =Vertical
CN =
STXH =Horizontal Copper-Nickel
SS =
StainlessSteel
(SpecifyType)
CoilType:
S=SingleWall
D=DoubleWall
RecoveryRating:
InGPHat100oF∆T
Example: STXCN-3600S
Averticallyinstalledsemi-instantaneoussteamfired
waterheaterwitha90/10Copper-Nickelpressure
vesselandsinglewallheatingcoilratedtoheat3600
GPHata100oFtemperaturerise.
Option Note
Anyandalloptionalequipmentforawaterheatermustbecalledoutinthewrittenspecifications.Amodelnumberinand
ofitselfdoesnotreflectanyoptionalequipmentselected.
Steam Consumption Formula
F∆ T x 8.33
o
GPH x
=
Lbs/Hr Steam
LatentHeatofSteam
SteamPressure(psi)
LatentHeat
0
970
2
966
5
960
10
953
15
946
20
939
25
933
30
929
40
920
50
912
Metric Conversions
Liters x 0.2641 = Gallons
psi x 0.06896 = Bar
Gallons x 3.79 = Liters
Bar x 14.5 = psi
Gallons x 0.003785 = m
psi x 6.86 = kPa
m x 264.2 = Gallons
kPa x 0.1456 = psi
1 C∆ T = 1.8 F∆ T
Lbs x 0.4536 = Kg
o
F = ( C x 1.8) + 32
Kg x 2.2 = Lbs
C = (oF - 32) x 0.556
ft2 x 0.0929 = m2
3
3
o
o
o
o
m2 x 10.765 = ft2
6
Piping Layouts
H
SINGLE
UNIT
ter
Wa
ot
Ou
t
To Drain
a
Ste
Co
nd
en
Re
te
sa
tur
m
p
Su
Re
ply
Dr
To Drain
DUAL
UNIT
Ste
Co
nd
Re
Co
7
e
cir
ld
a
ns
te
am
Re
n
tur
ly
To Drain
Dr
cu
lat
Wa
te
ion
r In
ion
ain
Ho
pp
lat
te
Wa
ld
o
C
n
Su
c
u
irc
ain
Dr
ain
tW
ate
rO
ut
r In
Piping Layouts
SINGLE
UNIT WITH
STORAGE
TANK
a
Ste
Co
nd
s
en
ate
tu
Re
rn
m
p
Su
ply
To Drain
Dr
te
Wa
t
Ho
u
rS
To Drain
ly
pp
Re
c
u
irc
lat
Ou
t
ion
te
Wa
d
l
Co
Ho
ain
ter
Wa
t
Ho
r In
a
tW
Re
ter
e
ragk
StoTan
tur
n
LEGEND
Strainer
Stop Valve
Check Valve
Control Valve
Relief V alve
Thermal Element
Pressure Gauge
Temperature Gauge
Steam Trap
Circulator
Expansion Tank
8
Master Specification: Model STX
Job Name
engineer
Representative
contractor
GENERAL
Provide a quantity of _________ semi instantaneous steam fired water heater(s), Model No. _____________________________
as manufactured by HUBBELL Electric Heater Co., Stratford, CT. The pressure vessel shall be mounted on heavy duty steel
structural supports and be suitably insulated, jacketed, painted and provided with lifting lugs. The entire unit is to be packaged
ready for service connections.
PRESSURE VESSEL
The shell section shall be constructed from 90/10 copper-nickel material. ( Optional Specification: Type 304 or 316L
stainless steel). Vessel shall be stamped for 150 psi under Section VIII of the ASME Code ( Optional Specification:
_____psi). Manufacturer’s data report and U-1 forms shall be furnished to the owner. No overhead clearance shall be required
for servicing or removing the heating coil. Each heater shall be designed to heat _________ GPH of domestic water from
________ to _________ oF when supplied with _________ psi of steam.
HEATING COIL
The heating coil shall be fabricated with single wall ( Optional Specification: Double wall) copper, ( Optional
Specification: Stainless steel, 90/10 copper-nickel, admiralty) tubes, non-ferrous baffles and a copper-lined tube sheet.
The heater shall have its temperature control bulb located for direct sensing of water.
CONTROLS
The water heater steam and operating controls shall be factory assembled and piped. A modulating steam control valve shall
be (Specify: Pneumatic, electric, self contained). Solenoid control valves that regulate the flow of steam to the heating coil shall
not be accepted.
Each heater shall be factory packaged with the following components:
• All bronze integral circulating pump with copper piping and isolation valves
• Direct mounted steam pressure and water temperature gauges
• High limit safety system
• ASME rated temperature and pressure relief valve
• Fiberglass insulation with painted metal jacket
• Cast iron strainers and F&T traps
OPTIONS
In addition, the water heater shall be supplied with the following optional features:
Option Option Option WARRANTY
The water heater manufacturer shall warranty all components against defects in Workmanship and material for a period of
one (1) year from date of start-up and the pressure vessel for a full five (5) years Non Pro-Rated ( Optional Specification:
full ten (10) years Non Pro-Rated) from date of start-up, provided that the unit is started within three (3) months of date of
shipment and installed and operated within the scope of the tank design and operating capability. Each water heater shall be
shipped with a complete set of installation and operating instructions including a spare parts list and approved drawing.
ISO 9001:2008
ISO
Made in the U.S.A.
Committed to continuous improvement...
Continuing research results in product improvement; therefore specifications are subject to
change without notice. For the most updated information, consult the factory directly.
The Electric Heater Company
■
P.O. Box 288 ■ Stratford, CT 06615-0288 ■ Phone: 203-378-2659
info@hubbellheaters.com ■ www.hubbellheaters.com
■
Fax: 203-378-3593