Packings may fail for a variety of reasons. Beside improper installation, packing failures are often due to worn or faulty equipment, shaft misalignment, uneven take-up on the gland bolts, and other causes.
If you are having trouble, carefully remove and examine the old packing set. DO NOT THROW THE SET AWAY, because it often gives clues as to the condition of the equipment, and may be the means of solving the problem. The following clues and possible causes were found by examining sets of packing which failed in service:
- CLUE 1: Excessive reduction in cross-section of packing directly beneath the rod, shaft or plunger.
- CLUE 2: Excessive reduction in the thickness of the packing directly over, or on eitherside of the rod or shaft.
- CLUE 3: A whole ring, or part of a ring is missing from set.
- CLUE 4: Wear on the outside of one or more rings.
- CLUE 5: Axial bulge in one or more rings.
- CLUE 6: Packings show tendency to extrude between rod or shaft, and the gland follower.
- CLUE 7: Rings next to gland follower badly damaged, with bottom rings in fair condition.
- CLUE 8: Wearing surface of rings dried and charred with rest of packings in good condition.
- CLUE 9: Innermost ring deteriorated.
POSSIBLE CAUSE: Rod or plunger out of alignment, and in the case of the rod or shaft, the bearings may be badly worn, causing whipping of the shaft.
POSSIBLE CAUSE: Bottom of stuffing box badly worn, with packing being extruded into the system.
POSSIBLE CAUSE: Rings rotating with shaft, or loose in the box. Packing too small.
POSSIBLE CAUSE: Adjacent rings cut too short or too long, depending on the style of material used, causing packing under pressure to be deformed.
POSSIBLE CAUSE: Excessive gland bolt pressure and/or too much clearance between rod or shaft and the gland follower.
POSSIBLE CAUSE: Improper installation of packings and excessive gland bolt pressure used.
POSSIBLE CAUSE:High temperatures and lack of adequate lubrication.
POSSIBLE CAUSE: Packing incompatible with fluid handled.
Priest Electric Can Provide You With All Types Of Packing For Any Project
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