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Engineering
& Design > Temperature Correction Factors
As the service temperature
increases, the maximum pressure a hose assembly can withstand decreases.
The material from which the hose is made and the method of fitting attachment
(mechanical, soldered, welded, silver brazed) determine the maximum pressure
at which an assembly can be used. By using the factors given in the chart
below, the approximate safe working pressure at elevated temperatures
can be calculated for assemblies with welded or mechanically attached
fittings.
|
Temperature
Correction Factors
|
|
Temp
(°F)
|
304,
316L
Stainless
|
321
Stainless
|
Bronze
|
Monel
|
Hastelloy
|
Inconel
|
|
Room
|
1.00
|
1.00
|
1.00
|
1.00 |
1.00
|
1.00
|
| 150 |
.96 |
.97 |
.92 |
.93 |
.97 |
.99 |
| 200 |
.92 |
.94 |
.89 |
.90 |
.94 |
.98 |
| 250 |
.91 |
.92 |
.86 |
.87 |
.92 |
.97 |
| 300 |
.86 |
.88 |
.83 |
.83 |
.91 |
.97 |
| 350 |
.85 |
.86 |
.81 |
.82 |
.89 |
.96 |
| 400 |
.82 |
.83 |
.78 |
.79 |
.87 |
.95 |
| 450 |
.80 |
.81 |
.75 |
.77 |
.86 |
.94 |
| 500 |
.77 |
.78 |
— |
.73 |
.85 |
.94 |
| 600 |
.73 |
.74 |
— |
.72 |
.84 |
.92 |
| 700 |
.69 |
.70 |
— |
.71 |
.82 |
.90 |
| 800 |
.64 |
.66 |
— |
.70 |
.81 |
.89 |
| 900 |
— |
.62 |
— |
— |
.79 |
.87 |
| 1000 |
— |
.60 |
— |
— |
.78 |
.86 |
| 1100 |
— |
.58 |
— |
— |
.75 |
.84 |
| 1200 |
— |
.55 |
— |
— |
.73 |
.82 |
| 1300 |
— |
.50 |
— |
— |
.69 |
.79 |
| 1400 |
— |
.44 |
— |
— |
.65 |
.77 |
| 1500 |
— |
.40 |
— |
— |
— |
.74 |
|
Saturated
Steam Pressure To Temperature (PSIG)
|
Saturated
Steam (PSIG) |
Temp
(°F)
|
|
Saturated
Steam (PSIG)
|
Temp
(°F)
|
|
Saturated
Steam (PSIG)
|
Temp
(°F)
|
| 0 |
212
|
|
150
|
366
|
|
450
|
460
|
| 10 |
238
|
175
|
377 |
475
|
465 |
| 20 |
259
|
200
|
388 |
500
|
470 |
| 30 |
274
|
225
|
397 |
550
|
480 |
| 40 |
287
|
250
|
406 |
600
|
489 |
| 50 |
298
|
275
|
414 |
700
|
505 |
| 60 |
307
|
300
|
422 |
800
|
520 |
| 75 |
320
|
325
|
429 |
900
|
534 |
| 80 |
324
|
350
|
436 |
1000
|
546 |
| 90 |
331
|
375
|
442 |
1250
|
574 |
| 100 |
338 |
400
|
448 |
1500
|
606 |
| 125 |
353
|
425
|
454 |
2500
|
669 |
|
Saturated
Steam Pressure To Temperature (Hg)
|
|
Saturated
Steam Vacuum
(in. of Hg)
|
Temp
(°F)
|
| — |
0
|
| 29.84 |
20 |
| 29.74 |
32 |
| 29.67 |
40 |
| 29.39 |
60 |
| 28.89 |
80 |
| 27.99 |
100 |
| 26.48 |
120 |
| 24.04 |
140 |
| 20.27 |
160 |
| 15.20 |
180 |
| 6.46 |
200 |
|
| Example |
| |
Determine
if 3/4" annular stainless hose with welded fittings is satisfactory
for the given operating conditions?
|
| Given: |
| |
Maximum
operating temperature is 700°F.
Maximum operating pressure is 200 PSIG.
|
| Computation: |
| |
From
the Series
300 specification table — nominal rated burst
pressure for 3/4" 312-SP0075 with welded fittings is 3200
PSIG.
From Temperature Correction Factors Chart — factor for
stainless at 700°F is .70
Rated
Burst Pressure: 3200 PSIG x .70 = 2240 PSIG
(rated burst pressure at 700°F)
Safe Operating Pressure: 2240 ÷ 4 = 560 PSIG(using 4:1 safety
factor)
|
| Result: |
| |
Since
the maximum operating pressure for 312-SP0075 at 700°F is 560
PSIG the hose will meet the required operating conditions outlined
above. |
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