Temperature Correction Factor

ISO 10380 — Temperature Derating Factors (C_t)

The maximum working pressure of an SS flexible hose falls as temperature rises. Multiply the hose's rated pressure at 20°C by the correction factor (C_t) for your material grade and operating temperature.

Max WP (corrected) = Max WP (20°C) × C_t

ISO 10380 temperature correction factors by stainless grade, with each grade’s maximum continuous-service temperature.
Material Grade	Max Continuous	20°C	50°C	100°C	150°C	200°C	250°C	300°C	350°C	400°C	450°C	500°C	550°C
SS304	425°C	1.00	0.88	0.73	0.66	0.60	0.56	0.52	0.50	0.48	0.47	0.46	0.45
SS304L	425°C	1.00	0.87	0.72	0.65	0.59	0.55	0.51	0.48	0.46	0.45	0.44	0.43
SS316	425°C	1.00	0.90	0.78	0.71	0.66	0.62	0.58	0.56	0.53	0.52	0.51	0.51
SS316L	425°C	1.00	0.88	0.74	0.67	0.62	0.58	0.54	0.52	0.50	0.48	0.47	0.47
SS321	700°C	1.00	0.92	0.83	0.78	0.74	0.71	0.67	0.64	0.62	0.61	0.60	0.59

Struck-through factors lie above that grade’s maximum continuous-service temperature. ISO 10380 tabulates a C_t value there, but the grade should not be specified for continuous service at that temperature — use SS 321 above 425°C.

Example: A hose rated 100 bar at 20°C in SS316 operating at 300°C → 100 × 0.58 = 58 bar corrected maximum working pressure.

NOTE 1 The derating factor at low temperatures for some austenitic materials is higher than 1 — contact the manufacturer. · NOTE 2 SS designations per ISO 9328-7. · Pressure ratings are for reference; we reserve the right to alter specifications as necessary.