Tubing

SSP Tubes are synonymous with Safety and Convenience for instrumentation tubing applications. Instrumentation tubing is designated according to its intended application, as well as by the type of mechanically attached fitting selected to join the tubing.

Instrumentation tubing is generally described as thin-walled tubing with strict requirements to deviation in diameter and wall thickness for leak-free operation on fluid transfer and pressure containment systems in process, oil & gas, natural gas, power, cryogenic, and performance-critical OEM industries. 

Safety

You already use high quality, specification controlled instrumentation tube fittings. You appreciate the control and precision in the engineered swaging process occurring through the interaction of body, nut, and ferrule(s). These components come from SSP inspected, assembled, and bagged for cleanliness. Tubing should also be shown similar consideration to ensure a leak free installation. It is counterproductive to purchase a high quality, mechanically attached tube fitting and use it with the cheapest available tubing. The quality of a mechanically attached tube fitting will be limited or compromised by the use of poor quality tubing. 

Purchasing tubing to ASTM, DIN or other equivalent specifications is a good start, additional requirements should be considered. Most industry specification allow for rather wide variation in several important factors. Furthermore these specifications don’t universally overlap thereby bringing into question the efficacy of tubing which is inside the specification controls limits of one specification but not another.

So simply using an industry specification does not really mean that you have selected quality tubing.

Restricted Tolerance Controls

• Material and Method of Manufacture
  SSP Tubes are generally Dual Grade where possible. Dual Grade means alloy with identical physical characteristics and only slightly different chemical characteristics are specification- controlled favoring the grade with the more refined chemical characteristics. 
  
  
• Hardness                                                                                                         
  All instrumentation tube fittings require that the tubing be softer than the fitting material. While most metal tubing is restricted to a maximum hardness measured on the Rockwell hardness scale, SSP Tubes have a lower restricted maximum hardness. This restricted tolerance control lowers installed cost by allowing the tubing to be more easily bent and installed.
  
  
• Surface Finish
  ASTM specifications are ambiguous on the subject of finishes. Instrumentation tubing should be free from nicks, gouges, and deep scratches which can interfere with proper sealing, particularly in gas service. SSP Tubes incorporate packaging and preservation standards which ensure that the tubing arrives in proper condition for use in instrumentation systems.

• Roundness
  ASTM A269 section 12.2 allows some thin-walled tubes to be produced with ovality of the tube twice the OD tolerance of ±.005”.   This degree of out-of-roundness would prevent the tubing from even inserting into the tube fitting properly. SSP Tubes has restricted this tolerance to better control ovality.                                     
  
  
• Dimensional - Wall Thickness & Outside Diameter
  Typical ASTM tubing specifications permit various tolerances larger and smaller than the nominal OD rating (aka “plus” and “minus”). SSP Tubes has restricted minimum tolerances on the “minus” because it is more difficult to seal undersized tubing reliably. 

Convenience

• Tube caps
  Plastic protective caps are installed onto the end of each SSP Tube to preserve internal cleanliness from the factory as well as to protect the end of the tube for maximum yield. Improperly protected tube ends must be trimmed prior to using the tube. Tube caps prevent wasted time and material associated with this practice.
  
  
• MAWP on lay line
  SSP Tubes improve system safety and increase installer and operator confidence by printing Maximum Allowable Working Pressure  [MAWP] in psig and bar right onto the tube lay line. This feature provides an additional measure of safety against using an inadequately rated tube in service. MAWP are calculated using widely accepted ANSI /ASME B31.3 Process Piping specifications and code calculations.
  

• Fabrication
  Virtually all tubes are prepared prior to installation. Preparation may involve:
  • bending
  • forming one or both ends by flaring or flanging the tube
  • presetting or installing a tube nut, ferrule(s) or sleeve
  • functional testing
  • cleaning & packaging

SSP Tubes are fully heat and lot traceable. Chemical composition, yield, tensile strength, and elongation testing is performed. SSP Tubes pass functional tests including flattening, flaring, dimensional, and leak testing via Eddy current to ASTM A-450, as required. Finally, SSP Tubes are re-inspected using Energy-dispersive X-Ray Fluorescence (EDXRF) technology.

Inspection certificates and summarized test results are issued with each tube of different size or lot. Certification is always issued in compliance with EN 10 204 3.1 and ISO 10474.