REMEDIES FOR SEAL FAILURE
Table 1 of 3
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Appearance

Cause

Remedy

Fact

Conditions

Hardening
Hardening of the whole sliding face. Glazing and cracks on the face. Push with a finger, and a crack is detected.

condition1
(1) Heat generation by high speed or excessive internal pressure. (1) In case of piston, change to SPG.
(2) In case of rod, use buffer ring together.
The whole packing hardens and changes into shape of groove and when bent with a finger, a crack occurs.

condtion2
(1) High oil temperature
(2) Influence of oil
(a) Incompatibility of oil and rubber material
(b) Deterioration of oil
(1) Lower oil temperature or change to hear resistant material (fluoro rubber).
(2a) Change to oil resistant rubber material.
(2b) Renew oil.

Wear
The sliding face is worn into a flossy mirror-like face.

condition3
(1) Sliding was extremely short stroke and caused insufficient lubrication. (1) In case of piston, change to SPG.
(2) In case of rod, use buffer ring together.
The size of sliding width continuously differs on the circumference and the position of minimum width and the position of maximum width are roughly symmetrical.

condition4
(1) Eccentricity of rod and cylinder head and cylinder and piston head. (1) Make eccentricity of installation within the tolerance of packings.
Abnormal wear of part of the circumference of the sliding lip (matching the direction lateral load).

condition5
(1) Abnormal wear of wear ring and bearing by excessive lateral load. (1) Change wear ring and bearing material to those which can withstand for large load.

Scars
Partial cut, dent on the top end of the lip.

condition6
(1) By external force such as by hanging on a nail or wire for storage.
(2) Insufficient chamfering of the mating material when fitting.
(3) By driver, etc. when fitting.
(1) Improvement to storage method.
(2) Increase chamfering of the mating material and make it smooth so as not to cause overturn.
(3) Use fitting tool.
Scratch on sliding face.

condition7
(1) There was a scar on the mating sliding face.
(2) Due to overturn.
(3) By embedded foreign material.
(1) Check fully before fitting.
(2) Make sufficient chamfering of the mating material and make it smooth so as not to cause overturn.
(3) Make sure to clean.