FOR STEEL AND STAINLESS STEEL TUBING BASED ON 4 - 1 SAFETY FACTOR
When using thick walled tubing where flaring is impractical, the use of Flareless Fittings is recommended. Pressures listed above are given in PSI. Selection of hydraulic tubing size is calculated by evaluating several different factors.
These factors include:
Type of fluid in the application
Maximum working pressure
Type of service (Normal, Severe, Hazardous)
Operating Temperature of application
Flow rate of application
Tubing design pressures can be calculated using one of three equations as shown in SAE - J1065. The values which are shown in the tubing design pressure chart were calculated using (LAME's) equation. Values as shown in the tubing design pressure chart are given using a safety factor of 4 to 1, which is rated for normal service.
P = S ( ( D2 - d2) / (D2 + d2) )
D = Outside tube diameter (Inches)
d = Inside tube diameter (Inches)
P = Recommended design pressure
S = Allowable stress of material (PSI)
** Values for allowable stress of materials
• C1010 Steel tubing: 12,500 PSI
• 304 and 316 Stainless tubing: 15,000 PSI
** Tubing design pressure values have not been
derated for severity of service or elevated
** Consult your tubing supplier for detailed
information regarding pressure and temperature
ratings for tubing.