SSP, a manufacturer of leak-free instrumentation fittings, tubes and valves for the offshore oil and gas industry, has released a free white paper on Offshore Technology on Duolok instrumentation tube fittings.

With a specialised technical centre built within SSP, the Duolok tube fittings have undergone:

  • Hydrostatic proof and burst pressure testing
  • Air and/or helium pressure testing
  • High vacuum testing
  • Cyclic vibration testing
  • Tensile pull testing
  • Hydraulic impulse testing
  • Thermal cycle testing
  • Low temperature (cryogenic) testing
  • High temperature testing

These tests determined, amongst other criteria, if the tube fitting assembly has adequate pressure-retaining capability, based on the ANSI / ASME B 31.3 maximum allowable working pressure of the tubing; if the tube and fitting assembly has comparable levels of assembly torque to that of Swagelok and Parker; if the tube fitting assembly has adequate pressure-retaining capability, based on the ANSI / ASME B 31.3 maximum allowable working pressure of the tubing; if the tube fitting assembly has high resistance to vibration-based fatigue when simultaneously exposed to 1.6 times tubing maximum allowable working pressure; and if all combinations of tube fitting components (nut, back ferrule, front ferrule and fitting body) of Duolok and Swagelokcan be intermixed in a tube fitting assembly, resulting in both adequate gas and liquid pressure-retaining capability.

In every case all Duolok test results met or exceeded the established design team’s acceptance criteria for these products.

To download this free white paper please click here.