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Calculating Condensate Loads
Warm Up Load ( Heating Loss )
This is the amount of condensate which forms at starting up a power plant to raise the
temperature of the metal of pipes, fittings, etc. to the operating temperature without including the
normal radiation loss. As far as calculating the condensation load during the warming up period
the required time is extremely important for sizing steam traps. Less warm up time increases the
necessary capacity per trap. Allowing more time for warm up permits the use of smaller traps in
smaller quantity.
W x (T-t) x Sp. Heat x 60
Q = —————————————
Lxm
Where Q = Quantity of Condensate ( Lbs/hr )
W = Total weight of pipes in LBS
T = Saturation Steam Temp ( °F )
t = initial temp of pipe ( °F ) usually surrounding air temp
m = minutes to heat up system
L = Latent heat of steam ( BTU’s/Hr )
www.velansteamtraps.com
1-800-860-0233
[email protected]
Normal Condensate Load ( Radiation Loss )
Once the system is heated up steam condenses due to normal radiation losses to the
surrounding air. These losses depend of course on the size and length of the pipe, on the
pressure of steam and its latent heat and mainly on the type and thickness of insulation. The
equation from which a normal regulation load can be calculated is:
F x HL ( T - t )
Q = ——————————
L
Where F = Length of Pipe (ft)
HL ( T – t ) = Heat loss/foot of pipe at the temperature differential between steam and air
Above Table
L = Latent heat of steam ( BTU’s/Hr. )
www.velansteamtraps.com
1-800-860-0233
[email protected]
Condensation Load for Sizing Steam Traps
The condensation load builds up from 0 to maximum at the point where the warming up load
drops to 0. It is assumed, therefore, that the peak is achieved halfway through the warming up
period. Therefore, for sizing of steam traps, we take the maximum amount of condensate during
the warming up period plus half of the radiation load.
Qt= QW + .5QR
Where Qt = Total condensation load at peak (LBS/Hr)
QW = Condensation load during warm up (LBS/Hr)
QR = Condensation load due to normal radiation loss (LBS/Hr)
Condensate in LBS/Hr created in steam mains 1” to 24” and pressure of 600 to 2500 PSI based
on the warm up period of 1 hour and 100 feet of pipe, and based on the above assumption is
shown in tables.
For shorter or longer heating up time, multiply by 60/m where m is the warm up time in minutes.
www.velansteamtraps.com
1-800-860-0233
[email protected]
Properties of Saturated Steam
Heat in
BTU/lb
Gauge Temp Sens
Pressure
°F
ible
PSIG
25
134
102
20
162
129
179
147
15
192
160
10
203
171
5
212
180
0
215
183
1
219
187
2
222
190
3
224
192
4
227
195
5
230
198
6
232
200
7
233
201
8
237
205
9
239
207
10
244
212
12
248
216
14
16
252
220
18
256
224
20
259
227
22
262
230
24
265
233
268
236
26
271
239
28
274
343
30
277
346
32
279
248
34
282
251
36
284
253
38
286
256
40
289
258
42
291
260
44
293
262
46
295
264
48
298
267
50
300
271
55
307
277
60
65
312
282
70
316
286
75
320
290
80
324
294
85
328
298
331
302
90
335
305
95
338
309
100
341
312
105
344
316
110
347
319
115
350
322
120
353
325
125
356
328
130
361
333
140
363
336
145
Heat in
BTU/lb
Latent
Total
1017
1001
990
982
976
970
968
966
964
962
960
959
957
956
954
953
949
947
944
941
939
937
934
933
930
929
927
925
923
922
920
918
917
915
914
912
909
903
901
898
895
891
889
886
883
880
878
875
873
871
868
866
861
859
1119
1130
1137
1142
1147
1150
1151
1153
1154
1154
1155
1157
1157
1157
1159
1160
1161
1163
1164
1165
1166
1167
1167
1169
1169
1272
1273
1173
1174
1175
1176
1176
1177
1177
1178
1179
1180
1180
1183
1184
1185
1185
1187
1188
1188
1189
1190
1191
1192
1193
1193
1194
1194
1195
www.velansteamtraps.com
Specific
Volume
Cu. Ft./lb
142
73.9
51.3
39.4
31.8
26.8
25.2
23.5
22.3
21.4
20.1
19.4
18.7
18.4
17.1
16.5
15.3
14.3
13.4
12.6
11.9
11.3
10.8
10.3
9.85
9.46
9.10
8.75
8.42
8.08
7.82
7.57
7.31
7.14
6.94
6.68
6.27
5.84
5.49
5.18
4.91
4.67
4.44
4.24
4.05
3.89
3.74
3.59
3.46
3.34
3.23
3.12
2.92
2.98
Gauge Temp Sens
Pressure
°F
ible
PSIG
150
366
339
155
368
341
371
344
160
373
346
165
375
348
170
377
351
175
380
353
180
382
355
185
384
358
190
386
360
195
388
362
200
390
364
205
392
366
210
394
368
215
396
370
220
397
372
225
399
374
230
401
376
235
240
403
378
404
380
245
250
406
382
255
408
383
260
409
385
411
387
265
413
389
270
414
391
275
416
392
280
417
394
285
418
395
290
420
397
295
421
398
300
423
400
305
425
402
310
426
404
315
427
405
320
429
407
325
430
408
330
432
410
335
340
433
411
345
434
413
350
435
414
355
437
416
360
438
417
440
419
365
441
420
370
442
421
375
443
422
380
445
424
385
446
425
390
447
427
395
448
428
400
460
439
450
470
453
500
479
464
550
489
475
600
1-800-860-0233
Latent
Total
857
855
853
851
849
847
845
843
841
839
837
836
834
832
830
828
827
825
823
822
820
819
817
815
814
812
811
809
808
806
805
803
802
800
799
797
796
794
793
791
790
789
788
786
785
784
783
781
780
778
777
766
751
740
728
1196
1196
1197
1197
1197
1198
1198
1198
1199
1199
1199
1200
1200
1200
1200
1200
1201
1201
1201
1202
1202
1202
1202
1202
1203
1203
1203
1203
1203
1203
1203
1203
1204
1204
1204
1204
1204
1204
1204
1204
1204
1205
1205
1205
1205
1205
1205
1205
1205
1205
1205
1205
1204
1204
1203
Specific
Volume
Cu. Ft./lb
2.74
2.68
2.60
2.54
2.47
2.41
2.34
2.29
2.29
2.19
2.14
2.09
2.05
2.00
1.96
1.92
1.89
1.85
1.81
1.78
1.75
1.72
1.69
1.66
1.63
1.60
1.57
1.55
1.53
1.49
1.47
1.45
1.43
1.41
1.38
1.36
1.34
1.33
1.31
1.29
1.28
1.26
1.24
1.22
1.20
1.19
1.18
1.16
1.14
1.13
1.12
1.00
.89
.82
.74
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Standard Dimensions for Schedule 40 Pipe
Examples:
Warm up loss
Ambient Temp = 70°F
Working Temp = 366°F (150psig)
Warm up time = 720 minutes
1000 feet of 10 inch Schedule 40 pipe weighs = 40483
Latent heat = 857
40483 x (366-70) x .12 x 60
Q = —————————————
857 x 720
Q = 472 lbs/hr
www.velansteamtraps.com
1-800-860-0233
[email protected]
Radiation loss
Ambient Temp = 70°F
Working Temp = 366°F (150psig)
Differential temp = 294°F
Differential multiplier = .98
1000 feet 10 inch Schedule 40 uninsulated pipe
Latent heat = 857
1000 x 2600 ( .98 [factor for 296° diff] )
Q = ——————————
857
Q = 2973 lbs/hr
Sizing for steam traps
Qt= QW + .5QR
.5QR = 1486.5 + QW = 472 = 1958.5
www.velansteamtraps.com
1-800-860-0233
[email protected]
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