Ceramic Vacuum Break, 3kV, 1.25" (31.8mm) ID Weldable

Part Number / SKU
Availability: 6 Weeks
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MDC Precision offers a complete line of vacuum breaks, also known as electrical isolators, for demanding ultra-high vacuum (UHV) applications and environments. Composed of metal adapters brazed to each end of an insulating ceramic tube that provides voltage isolation between the conductive metal ends, vacuum breaks provide an electrical break between the vacuum chamber and other external components, as well as electrostatic discharge (ESD) protection of sensitive components in the vacuum system. 

Constructed using high-purity alumina ceramic insulators hermetically bonded to low-expansion metal Kovar® sleeve adapters, the electrical breaks are attached to other vacuum components such as flanges, bellows, chambers and weldables using MDC’s proprietary UHV brazing techniques. All materials and braze alloys used are vacuum grade and chosen for their specific characteristics and ability to maintain the integrity of the seals for use in demanding applications and environments. A maximum thermal gradient of 25°C per minute must be observed to preserve the life of the seal. Weldable vacuum breaks are typically installed using one of the following fusing processes: laser, electron-beam or TIG welding. 

  • Weldable installation
  • Tapered ceramic-to-metal seal design geometry
  • UHV-compatible materials


  • Custom configurations upon request
  • Bellows
  • Non-magnetic, 316LN and titanium materials
  • Enhanced seal joint integrity
  • Exceptional hermiticity and performance
  • High purity and reliability


  • Weld Adapter                      304SS (1.4301 | UNS S30400) Stainless Steel
  • Sleeve                                  Kovar (UNS K94610)
  • Insulator                               92% min alumina ceramic

Vacuum Range                              1 x 10-10 Torr UHV

Temperature Rating

Del-Seal ConFlat (CF)                     -100°C to 450°C

ISO & Kwik-flange (KF)                  -20°C to 150°C

Weldable                                         -100°C to 450°C

Voltage                                           3,000V DC maximum

Weight                                            1.25 lbs. | 0.6 kg

RoHS / REACH Compliant

Reference                                      0138502

  • Fusion Energy
  • Particle Accelerators
  • Research Equipment
  • UHV

More Information


Weight (lb) 6.00
Reference Number 0138502
Vacuum Range UHV
Vacuum Series Ultra High Vacuum (UHV)
Voltage 3000
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