Dual sealing interfaces for applications requiring a controlled seal-support fluid
The Luwint MX2D combines two mechanical sealing interfaces in one cartridge assembly. It is intended for applications where seal selection requires closer control of lubrication, heat removal or process-fluid leakage than a single-seal arrangement can provide.
The cartridge brings the two seals, sleeve and gland together as an assembly. Its operation must be considered alongside the external seal-support system: selecting the cartridge and selecting the supporting fluid arrangement are part of the same task.
Why Choose MX2D?
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Two sealing interfaces: provides an intermediate fluid space between the process-side and atmosphere-side seals.
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Integrated cartridge assembly: reduces the separate components that must be positioned when installing a double seal.
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Controlled supporting fluid: allows lubrication and heat removal to be managed through a suitable external system.
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Material options: supports selection for different process liquids and operating conditions.
Selecting the Seal-Support Arrangement
A double cartridge requires a defined supporting-fluid specification, pressure relationship and supply arrangement.
Where a pressurised barrier-fluid configuration is approved, the fluid between the seals is maintained above the process-side seal-chamber pressure. Fluid compatibility with the process is important because some barrier fluid can enter the pumped liquid.
A lower-pressure buffer arrangement works differently and must not be assumed suitable for every double cartridge. Confirm the permitted MX2D configuration, pressure differential and piping requirements before selecting the support equipment.
Include the fluid supply, heat removal, monitoring and maintenance requirements in the installation specification.
Installation Space
MX2D requires more axial space than the corresponding MX2 single cartridge.
For the listed metric sizes from 24 to 70 mm, catalogue dimensions L1 and L2 are 35 mm and 54 mm. For 75 to 100 mm sizes, they are 39 mm and 58 mm.
Check the seal-chamber bore, insertion depth, gland mounting dimensions, external clearance and access to the support connections against the drawing.
Typical Operating Conditions
| Parameter | Catalogue specification |
|---|---|
| Listed metric shaft sizes | 24–100 mm, in selected sizes |
| Pressure | Below 2.8 MPa / 28 bar |
| Sliding speed | Below 35 m/s |
| Temperature | Dependent on elastomer selection |
The catalogue pressure is not a separately verified barrier-pressure or differential-pressure rating. Confirm these limits for the selected arrangement. Maximum pressure, speed and temperature must be assessed together.
Materials Available
| Component | Catalogue options |
|---|---|
| Seal faces | Carbon, silicon carbide (SiC), sintered silicon carbide (SSiC), tungsten carbide (TC) |
| Elastomers | NBR, Viton, EPDM, Aflas, Kalrez |
| Metal parts and springs | Stainless steel or Hast-C, as specified |
Select materials for compatibility with both the process liquid and the supporting fluid. Specify the face pairing for each sealing interface.
Applications in Australia
MX2D can be considered for chemical, oil and petroleum, pulp and paper, wastewater and food-processing duties where an engineered double-seal arrangement is appropriate.
For liquids with poor lubricating properties or demanding leakage-control requirements, selection should include a review of the complete seal-support system.
Sydney Supply. Help with Selection.
Send the pump details, shaft and seal-chamber dimensions, process conditions and existing seal photographs. Include the proposed supporting fluid, supply pressure and any existing reservoir or circulation equipment.
Contact Luwint for the MX2D catalogue, dimensional drawing, pricing, availability and dispatch timing.
Wayne Liao
Email: wayne@luwintonline.com
Phone: 0433 986 633