
Kinesis-RSS Techtips
How to properly install fittings
RheFlex® Stainless Steel (and titanium)
A good square-cut, burr-free end on tubing is important for use in your
system. The square-cut makes a flat surface for the tube to make contact
against the bottom of the valve port. Without this contact, a cavity will
form that causes high dispersion and peak distortion such as fronting,
tailing, or broadening.
To install the tubing:
a) Place the nut (1) and ferrule (2) with threaded portion of the nut
and tapered portion of the ferrule onto the tubing (3). See Figure 1A.
b) Insert the tubing into the valve port (4). Confirm that the tubing is bottomed in the valve port as shown in Figure 1B.
c) While firmly pressing down on the tubing, fingertighten the nut as tight as possible.
d) With the Rheodyne Wrench, designed especially for fittings, tighten 1/4 turn past fingertight. Remove the fitting to confirm that the ferrule is swaged onto the tube.


Figure. 1. Cut-away view of stainless steel fitting installation.
RheFlex PEEK Fittings and PEEK Tubing
PEEK tubing is flexible and easy to cut with a sharp blade. Confirm that
the ends are clean and straight and that the inner passage is fully open.
To install the tubing follow steps a–c in the stainless steel section
above. Fingertightening of 1/16" PEEK fittings is adequate to make
a leak-free connection. The 1/8" PEEK fittings need to be wrench-tightened.
The slotted backside of the ferrule (1) is squeezed down onto the tube
(2) by the mating conical surface in the nut (3). See Figure 2. The nut
and ferrule can both be reused many times. Unlike ordinary PEEK fittings,
Rheodyne's unique RheFlex PEEK design, specifically the angles and surface
contacts between the ferrule and nut, prevents the nut from gripping the
ferrule and twisting both the ferrule and the tube during tightening.
Otherwise, such twisting stresses the PEEK tubing and lowers the pressure
rating of the tubing. See RheFlex Fittings in the Fittings section.

Figure 2. Cut-away view of PEEK fittings installation.
An extensive Range of Rheodyne parts including the Rhebuild Kits are listed on the Kinesis website.
For more information or assistance please contact Kinesis Solutions sales@kinesis-solutions.co.uk
