Tobee® 3/2D HH High Head Slurry Pump DH078D21 Stuffing Box

Tobee Stuffing Box DH078D21

Slurry pump stuffing box

Stuffing Box

When centrifugal pumps were developed there was a need to prevent the pumpage from pouring out thru the open clearance between the pump casing back and the rotating shaft, which turns the impeller. This was accomplished by stuffing rope like material, called packing, into a cylindrical opening in the rear of the casing where the shaft passes through it. Packing is usually 1/4”, 3/8”, or 1/2” square cross sectional, the size to match the annular section between the shaft OD and the stuffing box ID. It comes in coils, and is cut to fit around the shaft OD. It is a soft material and usually has a lubricant in it. The opening, the stuffing box, has a shoulder at the bottom or “throat” (inboard end closest to impeller) and is fitted with a follower, called the gland, on the outboard end, which compresses the packing into the inner sides of the stuffing box against the shoulder in the bottom of the box, and against the rotating pump shaft. This effectively limits the leakage out of the pump. It will not completely prevent leakage. A small amount of pumpage must leak out of the pump in order to cool and lubricate the packing.