Failure Analysis of Plastic Components

Failure Analysis of Plastic Components & Water Supply Lines

1Toilet valve assembly with several material failure sites

2Severe mud cracking of plastic observed on trip lever due to exposure to chlorides

3Failure of plastic nut (white arrow) connecting float to anti-siphon valve body

4Fracture origin adjacent to surface material/manufacturing defect (red arrow)

5SEM image showing fracture origin (bounded by blue arrows) and adjacent surface defect (red arrow) in plastic

10Toilet tank showing flushing mechanism and pressure building capsule. Arrow indicates location of failed connector.

11Failed connector and spring

12Arrow indicates fracture on fitting from water supply line to pressure capsule. Loss caused by fatigue fracture in defective plastic material.

13Fractured plastic nut due to over tightening

14Overall image of toilet supply line

15Tool markings observed on plastic ballcock nut indicate improper installation

16Seal flattening shows evidence of extreme over tightening

21Stainless steel wire fractured due to exposure to acid species. Unsupported inner tubing burst.

22Failed braided stainless steel hose. White arrow indicates failure location.

20EDX spectrum of area adjacent to failure contains large amounts of corrosive agents: Sulfur (S), Phosphorus (P) and Chlorine (Cl), typically found in household cleaners