Quick-Flange vacuum fittings, known as QF, KF, NW or, in some instances DN, are a widely used flange-type connection system serviceable in rough to medium-vacuum systems. They offer reliable, convenient interconnecting of vacuum components.  

QF flange connections are simple to implement.These guidelines will ensure that your system delivers the best vacuum performance:

• Select proper O-ring material based on your system’s temperature, gas permeability and possibility of outgassing.
• Apply a very small amount of sealant to the o-ring.
• Ensure o-ring and flange faces are extremely clean.
• Tighten clamp hardware to compress O-rings no more than 25%.

These tips are part of our new white paper “QF/KA Flanges for Imporved Vacuum System Performance,” which provides greater detail (e.g., how to select the right O-ring material, when to use centering rings, when to avoid grease due to creep, and much more).