Looking for pictures of pipes or valves frozen and cracked
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This post was last edited by welding on 2021-5-21 09:23. Tees or valves on pipelines can suffer crack damage during use, but there is also a type of damage caused by freezing. In freezing conditions, tees or valves are prone to freezing and cracking. So, I would like to make a comparison regarding the visual differences between cracking that occurs under normal use and freeze-cracking. Please share your opinions or pictures to help clarify this.
Fittings used in the petrochemical industry are generally forged or extruded, so the possibility of them being damaged by freezing is low; even if freezing does occur, plastic deformation should take place first, as these fittings possess good plasticity. The same is true for valves; there are forged and cast versions. Cast stainless steel valves have good plasticity, while those with poor plasticity are cast iron and cast carbon steel valves, which have poor resistance to frost cracking.
Hehe, in the case of frost cracks, you can see ice at the damaged area; if it has melted, there will be water accumulated below. If metal fatigue or tensile cracking is caused by stress, and it is not affected by temperature, it generally falls under the category of non-frost cracking. Additionally, frost cracking is caused by forces moving from the inside outward. For reference.
This post was last edited by welding on 2021-5-22 at 13:36. Everyone, take a look at how this photo shows the cracks – can we determine the cause of those cracks based on this image?
What about the photo on the other side? It’s impossible to make a judgment with just one side, right?
It seems to be a phenomenon that occurs after vibration fatigue.
The other side is damaged, and even after taking a photo, the original condition cannot be seen.
It’s difficult to determine this way; it’s not possible to figure out the direction of the force based on the cracks on either side, and any further attempts to make judgments lack a basis. It’s not like the case of frost cracking, but again, there is no basis for such claims, and they aren’t convincing.
The phenomenon in which a metal splits into two parts under stress is called fracture. Fracture of metal materials can generally be divided into ductile fracture and brittle fracture, with both occurring sometimes. Ductile fracture of metals occurs after significant plastic deformation, and is characterized by slow crack propagation and a cup-cone-shaped fracture surface. Fracture by brittle failure is exactly the opposite; it generally occurs along specific mirror planes (also known as cleavage planes), with rapid propagation of cracks. This is the basis for judgment, so complete photos of the crack are needed.
Here is the image: a butterfly valve damaged by freezing in winter, with its outer ring and valve disc having separated due to freezing. The material is cast iron.