Page 132 - PRESS-FIT SYSTEMS FOR DIVERSE APPLICATIONS

3.0 TECHNICAL DATA
SYSTEM DESIGN CONSIDERATIONS

AND TUBE EXPANSION

A wide range of tube is offered for use with the XPress System covering XPRESS CARBON AND XPRESS STAINLESS
a wide range of applications.
The LBP feature on both XPress Carbon and XPress Stainless (sizes
15mm-54mm) is created by the use of a specially profiled EPDM O
NOTE: The bending of SS610 Stainless Steel tube ring.
manufactured to table 1, is not reommended.
The LBP O rings have been
However XPress Stainless tube, manufactured to table 2 shall be the specially designed to
preferred tube for bending in sizes up to 28mm.
incorporate a series of three
With the bending of carbon tube it is important to ensure the weld grooves in its surface through
seam is kept to the inside radius of the bend.
which water will leak from any
un-pressed fitting. When
CARBON STEEL SYSTEM TUBE: BENDS pressed, the O ring distorts,
Size Minimum Radii closing the grooves to create
15mm 53mm a fully water-tight and air-tight
18mm 63mm connection.
22mm 77mm XPRESS COPPER / XPRESS SOLAR
28mm 98mm Whilst the mechanical properties of XPress Copper with LBP are
different, the benefits are the same. The softer nature of copper
In sizes up to 28mm Carbon Steel System tube, is suitable for bending
using proprietary bend formers. enables the LBP feature to be incorporated into the O ring bead in
the fitting. The bead is slightly triangular in shape and this creates
Important: three spaces between the fitting and the tube through which water
XPress fittings must not come into contact with household will leak if the fitting is not pressed. One additional advantage of
cleaning products, paints, greases, fluxes, mineral oils, this system is that there is still sufficient contact between the O ring
adhesives or other solvent based materials that may be used and the tube to prevent it moving when inserted. When pressed
during installation, lagging or after installation. These materials the shape of the O ring bead is transformed from its triangular
may affect the O rings in XPress fittings. XPress fittings should shape to a round shape which, once again, is perfectly water-tight
not be painted.
and air-tight.
GAS O RINGS (AND O RINGS)
XPRESS ‘LEAK BEFORE PRESS’
Pegler Yorkshire does not recommend O rings are removed from
XPress Copper, XPress Carbon, XPress Stainless and XPress Solar offer a the standard product and replaced with a gas O ring. To prevent
unique ‘Leak Before Press’ feature (LBP) which enables any connections this gas O rings are not offered as spares within the XPress
which haven’t been pressed to be easily identified during pressure
testing at pressures as low as 0.5bar. accessories range. We only recommend gas fittings are purchased
as fully assembled products. We also do not recommend that gas
O rings are removed and replaced with standard O rings.

XPress
Copper Leak Copper
fitting path tube

Note: Contact between O ring
and tube, to maintain tube grip
Contact between tube, O ring and
fitting which fixates the tube

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