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-H101 HTM PW-H101 Automatic Green Jet 7510 PW-H100 HTM Green Jet 1010 PW-H100 P Stainless Steel PW-H90 Skid Fuego 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.