Vacuum Bellows and Flexible Metal Hose Purchasing Guide


Bellows and flexible metal hoses are ANCORP’s solution for vacuum applications involving prolonged vibrations and misaligned ports. Bellows are great for dampening vibrations, which can protect sensitive instrumentation, limit mechanical fatigue, and prevent loosening of bolt connections.

Hose Type

ANCORP offers two hose types: hydroformed hoses and PVC hoses.


Hydroformed hoses and bellows are inexpensive compared to edge welded hoses and provide sufficient flexibility for most applications.  The hydroforming process involves using immense water pressure to form a single piece of metal or tube into a preset mold.

ANCORP also offers PVC hoses, which are a low-cost solution for rough vacuum and exhaust lines. These hoses are ideal for corrosive applications and many chemical applications where metal is not suitable. PVC hoses feature a PVC covering around a metal coil that maintains structural integrity.

Wall Thickness

Most ANCORP bellows feature a thin wall starting at 0.006 inches that increases as tube O.D. increases. Bellows are recommended for roughing vacuum applications where maximum physical flexibility is desired.


ANCORP flexible metal hoses feature a medium wall of at least 0.008 inches that increases as tube O.D. increases. The thicker the wall, the less flexible the hose will be.

Flange and Length

Flange type and overall length will vary depending on the specifications of your system. ANCORP offers tube end, ConFlat (CF), QF (KF, NW), LF (ISO), and ASA flange options to fit many types of systems. Standard lengths range from 4-inches to 48-inches, with custom lengths available upon request. The longer the length, the higher the flexibility and the lower the conductance.

PVC hoses can be connected to a vacuum flange using a hose adapter. Hose clamps are required when connecting a hose adapter to a PVC hose. ANCORP offers both stainless steel and aluminum hose-to-QF flange adapters.

Braided vs. Unbraided (Optional)

A braided hose is an option that features metal braiding on the exterior of the hose. It provides protection for the medium wall metal hose from pressure, abrasion, impact and over-bending. Braided hoses are available upon request from ANCORP.


If you would like to see ANCORP’s full lineup of vacuum hoses, you can check out our Roughing Vacuum product page here. For further assistance configuring a bellows or hose for your system, contact us to speak with an application engineer.