SERTO Selection

SERTO has developed the SERTO Selection product range to meet the highest requirements for tightness and cleanliness in stainless steel connecting components. SERTO Selection stands for ultrasonically cleaned, lubricant-free stainless steel connections with electropolished surfaces and no dead space.

SERTO Selection UHP is a new development. It includes the union nut made of Nitronic®60, electropolished weld-on nipple made of stainless steel 1.4404 with PTFE or silver coating, the union body, also made of electropolished stainless steel 1.4404, as well as the electropolished weld-on elbow and tee.

The coated sealing surfaces are abrasion-free and the dead space-free design prevents dirt from building up on the components. All UHP products have a lasered production code for full traceability. The low leakage rate of 10‑11 mbar x l/s and the high resistance to pressure of up to 500 bar allow a wide range of applications.


Orbital welded connection SERTO Selection UHP

the best choice for Ultra High Purity applications


  • Union nut: Nitronic®60, with leakage test holes
  • Weld-on nipples: stainless steel 1.4404 (AISI 316 L), electropolished, sealing surface silver- or PTFE-coated
  • Bodies: stainless steel 1.4404 (AISI 316 L), electropolished
  • Weld-on elbow/tee: stainless steel 1.4571 (AISI 316 Ti), electropolished
  • Flat surfaces, threads and bore holes: rolled
  • Ultrasonic cleaning, vacuum-packed and double packed


  • Union nut: lubricant-free due to the Nitronic® material
  • Thread: abrasion-free as without coating
  • Sealing surfaces: virtually abrasion-free coating
  • Dead space free design and therefore no tendency for contamination
  • No additional expenses for separate sealing rings
  • Traceability thanks to the marked production code
  • Proven SERTO system – radial mounting/dismounting

Technical details

  • Installation: ~ 1/8 turn / approx. 20 repeat assemblies
  • Internal roughness  (iRa): ≤ 0.25 µm
  • Leakage rate: ≤ 10-11 mbar x l/s
  • Vacuum: up to 10-9 mbar
  • Temperature range: -70°C to +260°C
  • Resistance to pressure: up to 500 bar (fourfold safety), depending on the tube bursting pressure