E-Mail: aavolyn@bellatlantic.net

The AAVOLYN Type 217 set was developed to create a seal on the rod and in both
directions where there is not sufficient pressure differential to create a normal seal. As the
temperature increases in the sealing groove during operation, the female center ring rides up
over the two (2) male rings on either side. It pushes them down on the rod and back against
the Type 236 tangent ring. The Type 236 ring creates the end seal against surface of the wall
on each end of the groove. The side clearance of the Type 217 design is reduced to allow
this action to take place. This five (5) set is used after purge connections in the pressure
packing assembly to prevent any gas from escaping the packing case during operation and
when shut down under pressure. The TY 217 set may also be installed in distance PC
packings to serve the same purpose. It guarantees that no gas will enter the crankcase.

Type 217 Side Clearances - Both the TY217 five (5) ring set and the TY 215 three (3) ring set,
require reduced side clearances to allow the packing to function effectively. The expansion
coefficients of the sealing materials must be large enough to create this wedging effect in the
packing groove. The TY 217 set is double acting with sealing rings on each end.

TY 217 Pinning of the Rings - The size of the pin hole and clearance hole and their location
are important for this design to work effectively without the holes breaking through the ring
wall and providing a path for leakage. Normally plastic pins are used.

616 ORANGE ST.

P.O. BOX 1097

MILLVILLE, NJ 08332

Telephone: 856-327-8040

Fax: 856-327-9595

E-Mail: aavolyn@bellatlantic.net