1. ADVANCES IN SPRAY DRY NOZZLE BODY SEALING
OLD RADIAL BODY SEAL GLANDS (GAP) vs NEW AXIAL COMPRESIVE FACE TO FACE SEAL (NO GAP)
A NEW SEALING APPROACH WITH CLICK & DRY:
The new “Click & Dry” Spray dry nozzle is unique in the industry today by its use of two independent
compressive axial o-ring seals one at the orifice disc and the other at the nozzle lance adapter.
This seal arrangement is very different to the common radial lance adapter seals currently in use by
most customers, as can be seen in figures 1 & 2
CONSIDERATION OF BACKUP RINGS A THING OF THE PAST:
Pressure spikes (Maximum system pressures) can regularly exceed typical working pressures (stated
working pressures of systems). In some cases, not only the typical high working pressures, but the
severity of pressure spikes in most systems demands the use of Backup rings to support typical
nozzle radial seal o-rings to prevent run failures with the increased risk due to spikes. Click & Dry
sealing glands require no backup rings to satisfy most known potential pressure spike conditions.
THE PROBLEM WITHG RADIAL SEALS IN SPRAY DRY NOZZLES:
Radial type seals require a radial gap between gland components for constant assembly and
disassembly. It is this gap that is also subject to out of tolerance enlargement due to wear and
damage.
These Radial seal glands were never really designed, nor are ideally suited to the rigours of daily
assembly and disassembly and cleaning in the drier environment. An improvement was required.
MIND THE GAP:
The gap required in radial seals is the weakness that limits the maximum seal pressure. In many
cases the gap on many assemblies in use is too excessive to safely operate a radial seal within
accepted standards without the use of backup rings. This excessive gap is usually due to typical wear
that will be encountered in use.
Backup rings are cumbersome and expensive to use daily, and as such a better more reliable seal
system was required. Click & Dry full compressive axial face to face seal was the answer.
FIG 1

2. NO GAP REQUIRED WITH CLICK & DRY!
The Click & Dry sealing system requires NO GAP, in fact, the fact that no gap exists between
compressive sealing components means that the axial seal arrangement itself can handle far greater
sealing pressures that that of conventional radial seal arrangements. This means that the effect of
potential system pressure spikes (sometimes more than double the working pressure) upon seals
during use is far less an issue than previously with radial seals.
FIG 2
CLICK & DRY SEAL GLAND HAS LONGER SERVICE LIFE:
The click & Dry arrangement protects the sealing faces at assembly, disassembly and cleaning,
providing far longer component service life than conventional radial seal arrangements currently in
use.

3. SOME FACTS-VARIOUS WORLD WIDE SEAL STANDARDS LIMIT THE PRESSURE OF RADIAL SEALS
USED WITHOUT BACK-UP RINGS:
“With regard to the difference in the old and new sealing technology, the following
is a brief, but important overview and explanation from some of the World Wide
Standards that state why Radial Sealing Systems SHOULD NOT be used at typical
Dryer operational pressures, WITHOUT the added support of EXPENSIVE and
TROUBLESOME back-up rings, and how these awkward back up rings can be
avoided with the simplicity of the NEW Click and Dry Axial compressive Face to Face
Sealing :
*CASE (1) One of the most recognised Sealing Authorities is Parker Hannifin Corp. USA.
The Parker O-Ring hand book # 5700 “The O-Ring Seal-Sealing Bible”, in section (4)-2 states for
conventional plug and socket radial seal glands, that require an assembly gap, as per our
competitors offering, that:
“ Back-Up rings should be investigated for pressures exceeding 103.5 Bar ( 1500 PSI ) and that this is
true for all seal types.”
It also states in the same section that if there is no extrusion gap, as per our CD Axial compressive (
face to face ) sealing arrangement, that BACK UP RINGS ARE NOT REQUIRED !
It goes on to say further that in such face to face contact no gap situations, that sealing pressures of
up to 13,800 BAR ( 200,100 PSI ) with only a Duro 70 O-Ring being required WITHOUT BACK UP
RINGS !
It also importantly says that vibrations and pressure fluctuations, also requires back up rings on
conventional sealing arrangements, with a gap present. SIMPLY put the CD Click and Dry Nozzle does
NOT have a gap and WILL NOT need a back up ring; adding up to a huge saving of many thousands of
dollars a year in back up rings alone.
*CASE (2) The Australian O-Ring Standard # AS2842, O-Rings and Housings, in section Appendix A,
page 22 “o-ring selection” States:
For Pressures exceeding 10 MPa, ( 1450 PSI ), when diametrical clearances ( gaps ) of o-ring
housings, for either dynamic or static sealing, are in excess of those specified ( the working gaps in
conventional nozzles being in excess of those specified ), then it is recommended that back up
washers be used in conjunction with o-rings.
*CASE (3) DIN #3771 Part 5, Deutsche Norm, Page 1, section2: sealing configurations states:
If pressures are likely to exceed 100 bar in service, then this may be compensated for, by providing
back up rings, reducing the clearance ( the gap ).
*CASE (4) ISO 6162, and ISO 6164,
Are standards for High Pressure Connections For Services Up to 400 Bar, are based and characterised
on flange ( face ) sealing, not radial gland sealing with gaps.
The Click and Dry Nozzle, also utilises NO GAP Face to Face Sealing Technology !
*CASE (5) Japanese JIS B2406 Section 2.1.2, Clearances ( Gaps )
States where the clearances ( gap ) exceed the values noted, ( the working gaps in conventional
radial seal nozzles do exceed those noted) then Back Up Rings Shall be used jointly.
The standard also states that the Maximum working Pressure, with Minimal gap, and o-ring hardness
of Duro 90, shall not exceed 255 Mpa, which is typically BELOW normal Dryer design pressures.
BACK-UP RINGS ARE KNOWN TO BE HIGHLY PROBLEMATIC IN DAILY SRAY DRIER OPERATION!
CLICK & DRY IS THE NEW SEAL ARRANGEMENT SETTING NEW STANDARDS INTO THE FUTURE,
WHILE REDUCING OPERATING EXPENSES SUCH AS BACK-UP RINGS!