VHP High-performance fittings
Reliable fittings for extreme pressures
The IDEX VHP (Very High Pressure) series of high-performance fittings have all been designed for the extreme pressures encountered in HPLC and UHPLC analytical systems connecting 1/16” tubing OD to 10-32 coned ports. Some of the VHP fittings are manufactured from stainless-steel, some from a proprietary PEEK blend (PK), and some from a combination of the two.
The PK polymer blend has minimal cold flow properties relative to pure PEEK and can therefore withstand high pressures and temperatures up to 200 °C. Note though that the PK polymer may be conductive so caution should be used when employing PK polymer blend fittings in high voltage applications. The advantageous features of the PK material are utilized in several IDEX fitting systems including the One-Piece Fingertight, LiteTouch®, and MicroTight® designs.
The One-Piece Fingertight and LiteTouch® styles made from the PK polymer blend are pressure rated to between 12,000 psi (827 bar) and 16,500 psi (1,140 bar) depending on port and exact contraction. These fittings are designed for connecting 1/16” or 1/32” OD tubing to 10-32 or 6-32 coned ports.
The MicroTight® VHP PK fittings can hold tubing OD of 1/32” or 360 µm and are pressure rated to 15,000 psi (1,035 bar). They come both in a one-piece fingertight version for 6-32 ports and in a two-piece design comprising the MicroFerrues that fits to 5/16-24 coned ports with female MicroTight® nuts.
The patented reusable VHP fitting design, comprising a polymeric PK ferrule and a stainless-steel nut, tolerates 25,000 psi (1,720 bar) when tightened with 10 in-lbs (1.10 N·m) of torque. This construction allows quick component replacement with minimal downtime and is capable of up to ten repeat assembly cycles with no impact on pressure holding ability or carry-over.
Figure: Illustration of the how the dual-grip ferrule of the stainless-steel VHP fittings avoid deformation of the tubing internal diameter thereby preserving peak shapes in HPLC and UHPLC applications.
The stainless-steel VHP fittings include a unique two-piece ferrule system with two compression points to provide twice the grip of a standard ferrule. This design also allows the bite on the tubing to be less concentrated to avoid restriction of the inner diameter. To seal up to the stated 30,000 psi (2,070 bar) pressure rating, the VHP-200-01 ferrule requires 20 in-lbs (2.25 N·m) of torque.
Product details
LiteTouch® and One-Piece Fingertight VHP PK fittings
MicroTight® VHP PK fittings
Stainless-steel VHP fittings
Reusable stainless-steel VHP fittings
Resources
Consult the Periodic Table of Analytical Fittings for a quick overview, the Fittings 101 for guidance and learning, and the IDEX Catalogue for product details, or contact Biotech Fluidics for expert advice.
