Fault Phenomenon: Putzmeister M47 pumps normally when cold. When pumping high-grade concrete (operating temperature), the S-pipe switching becomes sluggish, wear accelerates, and eventually concrete leaks.

Troubleshooting Process:
– Checked cutting ring and wear plate: clearance adjusted normally.
– Checked S-pipe swing cylinder: cylinder action powerful, no internal leakage.
– Checked lubrication system: grease injection normal.
– Measured S-pipe swing pressure at operating temperature: found pressure builds slowly.

Root Cause: Insufficient nitrogen pressure in the S-pipe swing accumulator causes loss of cushioning effect under thermal conditions.

Required Parts: S-pipe swing accumulator and nitrogen charging tool.