When designing metal hose assemblies the pressure rating of the assembly is directly affected by the temperature the hose will be subjected too. If the design pressure is working at a temperature above ambient then the following temperature correction factors should be applied to work out the true pressure rating the hose should be designed to withstand.

For example if a 316L hose works at 20 bar at 300 deg C the actual rating of the flex should be designed to withstand 37 bar. This is worked out by applying the following calculation DP / 0.54(correction factor from table below) = 37 bar.

The hose would need to be designed to withstand 37 bar and not the 20 bar indicated.

Source: EN10380: 2012 – Derating factors and limiting temperature for European materials
Temperature °C

Material

20 50 100 150 200 250 300 350 400 450 500 550 600 650
1.4306-304L 1 0.87 0.72 0.65 0.59 0.55 0.51 0.48 0.46 0.45 0.44 0.43 / /
1.4301-304 1 0.88 0.73 0.66 0.60 0.56 0.52 0.50 0.48 0.47 0.46 0.42 / /
1.4541-321 1 0.92 0.83 0.78 0.74 0.71 0.67 0.64 0.62 0.61 0.60 0.59 / /
1.4404-316L 1 0.88 0.74 0.67 0.62 0.58 0.54 0.52 0.50 0.48 0.47 0.47 / /
1.4401-316 1 0.90 0.78 0.71 0.66 0.62 0.58 0.56 0.53 0.52 0.51 0.51 / /
1.4571-316Ti 1 0.90 0.81 0.76 0.73 0.69 0.65 0.63 0.61 0.59 0.59 0.58 / /
2.4856-Inconel 625
1 0.95 0.88 0.84 0.80 0.78 0.75 0.73 0.70 0.68 0.65 0.64 0.63 0.50
Note 1:           The derating factor to be applied to low temperatures for some of the austenitic materials listed is higher than 1. For further information, contact the manufacturer.
Note 2:           Stainless steel designations and values are specified in EN 10028-7 for 1% proof strength (C product form); carbon steel designations and values are specified in EN 10028-2 and nickel alloy designations are specified in EN 10095.