Sealing Code Compliance

Are your seals fit for purpose?

A major leakage & fire risk exists when the use of incorrectly specified, non compliant & poorly maintained spray dry nozzle seal gland systems. Consideration towards global sealing codes for high pressure spray dry nozzle sealing design is essential. These codes prescribe NO GAP seal arrangements to prevent seal extrusion & leakage at drier operating pressures moving above 100 BarG.

Radial Seal
The O-ring is always around the plug. The plug needs room to enter the socket to avoid rubbing damage. This room is what we call ‘gap’. However, the gap required for assembly is a problem, since high pressure seals demand no gap
Axial Seal
The O-ring is at the very end of the plug. The plug can have the room it needs to enter the socket thus avoiding rubbing damage, as the seal is at the end. There is NO GAP when the plug is firmly in place. This is ideal for high pressure sealing.

Fig 1: Old Spray Dry Seal Arrangement

which require radial assembly gaps. O-ring standards typically depict this radial seal type for operation pressures well below those found most in spray driers.


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: New Spray Dry Seal Arrangement
Axial compressive seal is designed for pressures well above typical dryer operating pressures according to O-ring standards.


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