This design of packing case is the oldest type to be used for mechanical packing
installations on reciprocating compressors. Originally, compressors & steam engines used
braided type packing for the low pressure ranges experienced. Braided packing required
constant adjustment of the gland which held the packing in place. This was necessary to
maintain a seal along the rod and to prevent leakage around the packing. Excessive
tightening could damage the shaft. As the packing wore in the bore from the reciprocating
motion of the rod, continuous tighting was necessary.
Mechanical packing replaced the braided design and required no adjustment to maintain a
seal after initial installation. This mechanical design uses a case to hold the individual rings
because controlled side clearance is required to allow the packing to function.
Limited space was available to install these original packing assemblies. A split housing is
installed over the rod and slipped into the stuffing box in place of the braided rings. The case
is held in place by the follower gland which was used with the original braided design.
