Ceradyne
manufactures balls and seats for check valves. The balls and seats are produced
from Ceralloy® 147-31N Silicon
Nitride. The valve balls are produced to Grade 25V. Silicon nitride is used
because of its high strength, fracture toughness and wear / chemical erosion resistance.
Valve balls are available from stock in sizes ranging from 5/8 inch (15.8mm) to
2 1/4 inch (57.1mm) in increments of 1/16 inch (1.6mm). Valve seats are manufactured
to custom designs upon request.