M421 Anti-scale M421 Anti-scale PREVENTS DAMAGE CAUSED BY HARD WATER. The daily use of the IPC anti-scaling compound reduces maintenance operations on the machine’s hydraulic circuit, thus preserving heating performance. Applied to: PW-H100 P Stainless Steel PW-H50 PW-H90 PW-H100 Skid Fuego V 200 MD-H V 200 MD SIL Twock-H Benefits Provides corrosion protection to components in contact with water. Reduces maintenance costs due to overpressure on coil pipes with limescale build-up. Prevents limescale from forming inside the hot water pressure washer coil, thus reducing fuel costs caused by heat loss.