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SUPERLOK® Tube fittings > Tube standard information



  Tube Standard Information
   
  Tube Selection
  Suitable tubing selection is essential in performance of tubing system. When selecting tubing material, size and wall thickness, customer must consider pressure, flux (flow), temperature, environment and compatibility of system.
Consideration facts at the selection of tube
1. Quality of the tube materials & manufacturing method.
2. Thickness and outer diameter of tube.
3. Surface treatment of tube .
4. Hardness of tube.
5. Concentricity of tube.
   
  Tube Bending
  In case of bending tubing near at SUPERLOK fittings, there should be enough lineal distance from bending point to the fittings as this can be a reason of leakage. (see the below Table).
This is essential to protect customer's system from the leakage. The required straight line length of tube should be bigger than tube diameter. For more detailed specifications and technology data, we suggest you to contact SUPERLOK engineers.
The recommended straight line length of tube in Tube bending
 
Tube O.D.(inch)  1/8  3/16  1/4  5/16  3/8  1/2  5/8  3/4  7/8  1
L(mm) 12.70 18.25 19.05 20.63 22.20 23.81 30.16 31.75 33.30 38.10
L: The straight line length of tubing from the ending part of tubing to the begining part of bending
   
  The requirements for tube quality of the material
Carbon steel tubing
• ASTM A179 or equivalent.
• Carbon steel tubing for an oil pressure usage of high quality, annealed and seamless.
• Maximum hardness : HRb72.
• Tubing must be free from scars and shall be suitable for bending and expansion works.

Copper tubing
• ASTM B65, B75 or equivalent.
• Copper tubing of high quality, annealed and seamless.

Stainless steel tubing
• ASTM A213, A269 or A632 or equivalent.
• Stainless steel tubing for an oil pressure usage of high quality, annealed and seamless. (316, 304, 321,etc.)
• Hardness : below HRb 80.
• Tubing must be free from scars and shall be suitable for bending and expansion works.

Monel tubing
• ASTM B165 or equivalent.
• 400 alloy tubing of high quality, annealed and seamless.
• Hardness : below HRb 75.
• Tubing must be free from scars and shall be suitable for bending and expansion works.
 
A pressure Grade Coefficient of Tubing owing to Temperature Change.
Table 1
°F °C Copper 304SS 316SS Monel
200 93 0.80 1.00 1.00 0.88
400 204 0.50 0.93 0.96 0.79
600 316 --- 0.82 0.85 0.79
800 427 --- 0.76 0.79 0.76
1000 538 --- 0.69 0.76 ---
1200 649 --- 0.30 0.37 ---
Multiply the allowable working pressure in Table 2, 3, 4, 5 by the coefficient in Table1 in order to decide allowable
pressure at high temperature. ( See page Tecnological information)
 
Example
SUS316
(3/8" O.D of tube) X (0.049" wall thickness)
1200°F 4800 psi X 0.37 = 1776 psi
The applicable operation pressure of SUS 316 tubing for wall
thickness, 3/8" O.D X 0.049" , is 1776 psi at 1200°F