Slant/Fin Caravan LDWO-1100-3-6 Application Manual page 12

NOTE: NFPA requires that the pump inlet pressure not
exceed 3 psi. Therefore, when oil is fed by gravity from above
the pump, the height should not be more than 8' from the
pump to the top of fuel oil supply. If it is more than 8', then
one way to protect the pump is to have a vacuum operated
safety valve (OSV) on each fuel unit.
PSEUDO TWO PIPE LOOP SYSTEM (Figure 15)
Another way to prevent overheating and thermal expansion of
the oil while the unit is running on gas for extended periods, is to
use a pseudo two pipe loop system (Figure 15). This system
Table 7. Dual Fuel Caravan Ratings Hot Water Models - LWDF Series (75 psi maximum working pressure)
No. of
Htg.
Model No. Mod.
LWDF-600-2-5 2
LWDF-750-2-6 2
LWDF-850-2-7 2
LWDF-900-3-5 3
LWDF-1100-3-6 3
LWDF-1300-3-7 3
LWDF-1700-4-7 4
LWDF-2100-5-7 5
LWDF-2500-6-7 6
LWDF-2900-7-7 7
LWDF-3400-8-7 8
* Light oil, 140,000 Btuh per gallon.
† Net ratings are based on a piping and pick-up allowance of 1.15.
Slant/Fin should be consulted before selecting a boiler for installation having unusual piping and pick-up requirements.
‡ Based on 150 Btuh per square foot E.D.R. at 170°F average water temperature.
§ Modules in excess of 8 are piped in parallel to first eight.
For larger sizes, use multiples of the above.
Firing
Rate
CCFH
Fuel Input
GPH
Gas 620 620
Oil 4.30* 602
Gas 750 750
Oil 5.20* 728
Gas 800 800
Oil 6.00* 840
Gas 930 930
Oil 6.40* 896
Gas 1125 1125
Oil 7.80* 1092
Gas 1200 1200
Oil 9.00* 1260
Gas 1600 1600
Oil 12.00* 1680
Gas 2000 2000
Oil 15.00* 2100
Gas 2400 2400
Oil 18.00* 2520
Gas 2800 2800
Oil 21.00* 2940
Gas 3200 3200
Oil 24.00* 3360
uses a booster pump to circulate the oil from the tank to a
header that feeds the burners. Excess oil is fed back to the
tank. Generally, a 1/2" fuel line should handle most installations
within 200' when using a type "A" pump. A duplex pump-motor
boost system should be wired to run for oil as well as for gas.
Whenever a burner (regardless of fuel) is running, one of the
duplex pump motors should be activated and another pump
motor should serve as an automatic backup.
Ratings
‡ EDR I=B=R
Water Net
Gross
(Sq. Ft.) (MBH)†
Output
500 2900 435
592 3433 515
622 541
3607
674 586
4347 652
750
3680 682
888 5147 772
933 5407 811
1011 5860 879
1244 7213 1082
1348 7813 1172
1555 9013 1352
1685 9767 1465
1866 10820 1623
2022 11720 1758
2177 12620 1893
2359 13673 2051
2488 14420 2163
2696 15627 2344
Table 8. Line Length for Two-Stage Fuel Unit
Two Pipe
Lift Ht.
1'
2'
3'
4'
5'
6'
7'
8'
9'
10'
11'
12'
13'
14'
15'
A = B82 Series Suntec Pump 63 GPH gear capacity.
B = B89 Series Suntec Pump 75 GPH gear capacity.
12
Recom-
mended
Water
Ship
Horse- Content
Wt.
(gal.)
power
14.9 31.0 1650
17.7 35.6 1870
18.6
45.2 2080
20.1
22.4 46.5 2475
26.5 53.4 2805
27.9
67.8 3120
30.2
37.2
90.4 4160
40.3
46.4
113.0 5200
50.3
55.7
135.6 6240
60.4
65.0
158.2 7280
70.5
74.3
180.8 8320
80.5
1/2" O.D. Tubing 5/8" O.D. Tubing
A B A
118 99 328
113 95 313
107 90 298
102 86 283
96 81 268
91 76 253
86 72 238
80 67 222
75 61 207
69 58 192
64 54 177
58 49 162
53 44 147
47 40 131
42 35 116
Header
Size§
2"
2"
3"
3"
3"
3"
3"
3"
3"
4"
4"
B
276
263
250
237
225
212
200
187
174
161
148
136
123
110
98