A.O. Smith HWG Technical Documents

Packaged Hot Water Generating

Systems - Steam / Hot Water

STEAM / HOT WATER MODELS HWG

FEATURES

A. O. Smith hot water generators are available for operation with steam or boiler water as the energy source. They are completely assembled with components sized, piped and checked at the factory before shipment. Generators are available in space saving vertical or horizontal models.

CUSTOM UNIT AVAILABILITY - Custom units built to order, with tank capacities

up to 12,000 gallons, with special control trim, and with special heating units can be built to design speciﬁ cations on special order basis. Standard units listed inthis brochure cover most standard orders.

INSULATION AND JACKETING - The HWG systems meet or exceed the thermal

efﬁ ciency and or standby loss requirements of the U.S. Department of Energy and current edition ASHRAE/IESNA 90.1.

CODE LISTING - The standard system will employ an ASME”HLW” code glass-

lined storage tank ﬁ tted with an ASME “U”code 3/4” diameter copper tube heat exchanger.

HWG MODELS

INTEGRAL PUMP - The standard HWG system will employ an integral bronze

circulator pump. The standard heat exchanger sizing tables are also based on using integral circulators.

HWG OPTIONS (STEAM OR WATER BOILER UNITS) - Low water cutoff,

alarm horn, 11x15 vessel manway, 4x6 vessel hand hole.

STEAM UNITS - Standard steam trim consists of temperature control valve, inlet

and auxiliary steam traps, inlet and auxiliary strainers, steam pressure gauge with siphon, vacuum breaker and air vent.

OPTIONAL STEAM TRIM - Includes steam pressure reducing valve, electric high

limit safety system, pilot operated controls, pneumatic controls.

BOILER UNITS - Standard boiler water trim includestemperature control valve and

boiler water temperaturegauge.

OPTIONAL BOILER TRIM - Electric high limit safety system,

three-way controls with bypass and boiler water pump. ASME RATING - Standard HWG consists of ASME HLW Code storage tank rated 125 psig working pressure with U Code heat exchanger, temperature & pressure relief valve, temperature & pressure gauge in tank, drain valve and lifting lugs.

CATHODIC PROTECTION - Standard HWG systems employing glass, cement or

epoxy lined tanks are ﬁ tted with magnesium anodes as cathodic protection.

LIMITED WARRANTY OUTLINES GLASS-LINED, CEMENT, EPOXY:

ﬁ rst ﬁ ve years, under the terms of the warranty, A. O. Smith will repair or replace the tank; installation, labor, handling and local delivery extra.

If the tank should leak any time during the

THE COIL HAS A ONE YEAR LIMITED WARRANTY.

NOTE: THIS OUTLINE IS NOT A WARRANTY.

consult the written warranty or A. O. Smith Water Products Company.

August 2014R

For complete information,

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Packaged Hot Water Generating

Systems - Steam / Hot Water

TO SPECIFY HWG SERIES PACKAGE WATER HEATER:

1. Calculate storage capacity in gallons required, and determine if vertical or horizontal installation applies.

2. Decide what type of heating medium will be used; steam or boiler water.

• If STEAM - Determine pressure in coil.

• If BOILER WATER - Determine available boiler water temperature.

3. From the recovery table, obtain the required GPH capacity and temperature rise. Selecting heating coil size.

4. Decide whether single or double wall coil is required.

EXAMPLE INSTALLATION REQUIREMENTS:

Vertical, 140 gallons, Steam @ 5 PSIG, 80 GPH Recovery, 40 - 140°F temperature rise.

TO DETERMINE THE HWG SERIES MODEL:

Storage Tank ................................. 140 Gallons, Vertical

Coil Size ........................................ 4-18 (from RECOVERY CHART)

MODEL TO SPECIFY:

HWG - 140 V ES S 4-18

Heating Coil Size S = Steam, W = Water S = Single Wall, D = Double Wall V = Vertical, H = Horizontal Gallons

Table HWG-1 GALS./HR RECOVERY (BASED ON CIRCULATING TANK)

STEAM PRESS COIL SIZES (DIA.-LENGTH)

IN COIL (PSIG)

40 - 140°F

50 - 140°F

60 - 140°F

0 72 164 320 508 788 1080 1640 1980 2240 2440 3320 4080

5 83 190 370 588 912 1250 1898 2292 2593 2824 3843 4723

10 90 205 400 635 985 1350 2050 2475 2800 3050 4150 5100

15 96 218 425 674 1046 1434 2177 2628 2974 3239 4407 5416

20 104 236 460 730 1133 1553 2358 2846 3220 3508 4773 5865

0 78 179 349 554 859 1177 1178 2158 2442 2660 3619 4447

5 89 203 395 627 973 1334 2025 2445 2766 3013 4100 5039

10 97 222 433 687 1066 1461 2218 2678 3030 3300 4490 5518

15 105 239 466 739 1147 1571 2386 2881 3259 3550 4831 5936

20 110 251 490 777 1206 1652 2509 3029 3427 3733 5080 6242

0 87 198 386 613 952 1304 1980 2391 2705 2946 4009 4927

5 99 225 438 696 1080 1480 2247 2713 3069 3343 4548 5590

10 107 243 474 753 1168 1601 2431 2935 3321 3617 4922 6049

15 115 262 511 812 1259 1725 2620 3163 3578 3898 5304 6518

20 122 278 543 862 1338 1833 2784 3361 3802 4142 5636 6926

4-18 4-36 6-24 6-36 6-54 8-42 8-60 10-42 10-48 12-36 12-48 14-42

ESS = Single Wall Steam EDS = Double Wall Steam ESW = Single Wall Water EDW = Double Wall Water

Table HWG-2 G.P.H. RECOVERY WATER-WATER (CIRCULATING TANK) W/TEMPERATURE RISE (40°-140°F)

COIL SIZES (DIA.-LENGTH)

4-18 4-36 6-24 6-36 6-54 8-42 8-60 10-42 10-48 12-36 12-48 14-42

180°F BOILER WATER 45 87 149 223 335 502 707 949 1079 1135 1544 1823

MINIMUM GPM REQ'D 4 7 13 19 28 42 59 79 90 95 129 152

212°F BOILER WATER 69 135 230 346 518 778 1094 1469 1670 1757 2390 2822

MINIMUM GPM REQ'D 6 12 20 29 43 65 91 122 140 146 200 235

NOTES:

1. Other coil sizes available.

2. Consullt factory for design parameters outside this chart.

For Technical Information and Automated Fax Service, call 800-527-1953. A.O. Smith Corporation reserves the right to make product changes or improvements without prior notice.

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