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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 determines the
maximum pressure at which an assembly can be used.
By using the factors given in the chart, the approximate safe working
pressure at elevated temperatures can be calculated.
| |
|
Temperature Correction Factors |
|
Temp. |
|
|
Carbon |
|
(Deg F.) |
T321/T316L |
T304 |
Steel |
|
70F |
1 |
1 |
1 |
|
150F |
0.97 |
0.96 |
0.99 |
|
200F |
0.94 |
0.92 |
0.97 |
|
250F |
0.92 |
0.91 |
0.96 |
|
300F |
0.88 |
0.86 |
0.93 |
|
350F |
0.86 |
0.85 |
0.91 |
|
400F |
0.83 |
0.82 |
0.87 |
|
450F |
0.81 |
0.8 |
0.86 |
|
500F |
0.78 |
0.77 |
0.81 |
|
600F |
0.74 |
0.73 |
0.74 |
|
700F |
0.7 |
0.69 |
0.66 |
|
800F |
0.66 |
0.64 |
0.52 |
|
900F |
0.62 |
|
|
|
1000F |
0.6 |
|
|
|
1100F |
0.58 |
|
|
|
1200F |
0.55 |
|
|
|
1300F |
0.5 |
|
|
|
1400F |
0.44 |
|
|
|
1500F |
0.4 |
|
|
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Example: Determine is 3/4” annular stainless
hose with welded fittings is satisfactory for the given
operating conditions.
Given: Maximum operating temperature is 600° F.
Maximum operating pressure is 300 Psig.
Computations: From the series MMHSS1 Hose Type -
nominal rated burst pressure for 3/4” MMH series with welded
fittings is 3520 Psig. From Temperature Correction Factors Chart
factor for stainless T321 at 600°F is .74
Rated Burst Pressure:
3520 Psig x .74 = 2604 Psig
(Rated burst pressure at 600°F)
Safe Operating Pressure:
2604 divide by 4 = 651 Psig
(using 4:1 Safety Factor)
Result: Since the maximum operating pressure for
MMH- SS1 Hose Type at 600° F is 651 Psig the hose will meet the
required operating conditions above.
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