Wear diagnostic on non-return check valves 1

[Alelo]

I need to know how to do an appropriate diagnostic of wear of a non-return check valve, in order to predict his failure or bad operating. What we usually do is to check the variation in the cushion of the injection stroke and the weight of the articles. However it doesn’t work well as a predictive maintenance.

I’ll appreciate any suggestion or comment you could give me.

Thanks.

 

[patprimmer]

Consistent, stable cushion and part weight are the only methods I know of, short of pulling the screw.

Obviously experience with previous life with known materials might help, if you have consistent material useage.

You could get an early warning by periodically taking a few shots in a very low viscosity (high MFI) material as these will be more sensitive to checkvalve leakage. Also use longer hold times in tests. Pressure is a bouble edged sword, as it might accelerate leakage rate, or help force a seal. Regards
pat