| Compressor rings or pressure rings:
to seal gases above the piston and prevent gas leakage. Commonly used is
called rams-bottom type made of cast iron + chrome coated, uniform section of
either square or rectangular, inside of the ring is hammered. Oil control rings or scrapper rings- rings for controlling the lubricating oil passed up and down Oil- spreader rings- used for spreading oil evenly in the liner.(oil rings are used in 4s or stuffing box) |
Since very small needle lift is obtained in the test equipment result in an unequal pressure distribution in the cut off shaft resulting in a hard contact in a small area along with high frequency oscillations, low lubricity of test oil will increase the chance of seizure. Full lift and high lubricity of heavy oil eliminates this risk of seizure during normal operation.( Always open and clean slide type valves before testing as cold sticky heavy oil along with small clearances can cause restriction in the movement of the spindle).
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