GPPT – General Purpose Permeation Teflon


The GPPT Accu-Flow™ model helium calibrated leak standard, which features a Teflon® permeation-style leak element, is widely used to tune and calibrate helium mass spectrometer leak detectors and leak testing systems. It is part of a family of VTI calibrators that includes the GPP, GPC and CLP calibrated leaks. Together, they cover leak rates as small as E-12 and as large as E-3 atm-cc/sec, and larger. Those models are detailed in other brochures, and VTI’s experts are always eager to help you select the best model for your application.

The GPPT Accu-Flow™ calibrated leak uses a thin Teflon® membrane as the flow rate control element. The helium reservoir is under pressure, and gas permeates through the Teflon® from the pressure side to the exhaust side of the element. This yields a precise, constant flow rate which is then used for calibrating helium leak detectors and other applications.

GPPT leaks features an all-welded stainless steel construction for reliability. Most leaks require a shut-off “isolation” valve to zero the leak signal during tuning and calibration. VTI offers the GPPT Leaks both with and without a Teflon®- packed stainless steel shut-off valve. The inlet port of the brand of leak detector or vacuum system determines the termination of the leak.

All leaks are available with QF (NW, KF), Normal Pipe Thread, VCR® and many other types of fittings. All GPPT Leaks are provided with certifications of the NIST-traceable calibrations performed in our A2LA-accredited Calibration Laboratory.

  • Never clogs: permeation leak element eliminates the threat of clogging
  • Versatile: available leak-rate ranges from e-4 to e-9
  • Durable: made of all-welded stainless steel
  • Long-lasting: reservoir never needs to be refilled
  • Simple: minimal user training required
  • Meets ISO requirements: NIST-traceable, A2LA-accredited Calibration Certification

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