MECO Ex-PAC seals combine the best features of MECO’s patented EAS and MECO-PAC seals into a superior product, which excels in some of the least hospitable process environments. Ex-PAC seals are often used on conveyors and agitator shafts in reactors, dryers and other equipment where aggressive solvents and other chemicals are present. They can be used in applications where there is extensive thermal growth of the shaft, or where axial shaft movements are occasionally necessary for adjusting machine clearances. Ex-PAC seals are frequently installed on extruder-compounders.



The Ex-PAC utilizes a massive housing similar to a stuffing box, containing rotating components which use the traditional MECO elastomeric drive, or in some cases the patented MECO-DR positive drive system. The MECO-DR system can be constructed without elastomers, where chemical environments dictate. The purge chamber between the two rotating faces is maintained by a tight-fitting "O"-ring around the nose of a gland follower, which in turn compresses the double seal faces.

While Ex-PAC seals can be equipped with traditional manual adjustment, they are more commonly loaded with external springs to compensate for normal wear of the sacrificial seal surfaces. Where conditions dictate, Ex-PAC seals can be fitted with pneumatic adjusting cylinders, so that seal face pressures can be adjusted by altering applied air pressure.

When equipped with the MECO-DR driving system, the Ex-PAC seal provides exceptional service in abrasives and where the process cycles from pressure to vacuum and back. A variety of materials for housings and wear parts permits compatibility with most chemical environments and processes under 500 degrees F. Ex-PAC seals can be configured with a variety of purge or flush arrangements, depending on process requirements.