The NPC ® Valve Impellers, as precision parts, handle radial clearances of 0.006 mm – 0.012mm.  This is achieved due to its design and the highest quality materials with which they are manufactured, such as steel alloy with special treatments (tempered by rapid cooling), that confer additional characteristics such as hardness, durability and resistance against thermal fatigue.  Also, the high-precision machining and the high-precision measurements are made with numerical control equipment.

The NPC ® Impellers are designed to effectively face the extreme working conditions.  This is basically due to its high resistance material that can tolerate 150 million cam strokes during its operational life, loads of more than 800 kg per stroke and extreme temperatures.

Its surface finish is under Ra 0.2 and its roundness is of 0.001 millimeters, in order to guarantee a perfect leak tightness and harmony of movement between the different pieces.