Cracking on Mech Seal
Cracking on Mech Seal
(OP)
A colleague just asked me about this: http://i68.photobucket.com/albums/i19/r34racer01/I...
My manager thinks it's thermal shock, but I believe this seal is tungsten-carbide so that should not have been an issue, right? They're pumping water in this system and it's not definite but we think it's above boiling. No glycol to our knowledge.
Any ideas what caused this failure?
My manager thinks it's thermal shock, but I believe this seal is tungsten-carbide so that should not have been an issue, right? They're pumping water in this system and it's not definite but we think it's above boiling. No glycol to our knowledge.
Any ideas what caused this failure?





RE: Cracking on Mech Seal
RE: Cracking on Mech Seal
"Empty your mind, be formless, shapeless — like water. Now you put water in a cup, it becomes the cup; You put water into a bottle it becomes the bottle; You put it in a teapot it becomes the teapot. Now water can flow or it can crash. Be water, my friend." -Bruce Lee
RE: Cracking on Mech Seal
Tungsten carbide in not compatible with: TUNGSTEN CARBIDE reacts violently with F2, ClF3, IF5, PbO2, NO2 and N2O (oxidants). It is readily attacked by a nitric acid-hydrofluoric acid mixture. May ignite in cold fluorine.
RE: Cracking on Mech Seal
RE: Cracking on Mech Seal
The picture shows fractures directly comparable to what you get when something metallic get a mechanical induced shock. A chemical reaction would in my opinion show other types of damage on the surface in addition. Searching I found an article on how 'sturdy and solid' wedding rings of tungsten carbide breaks when they hit concrete.
My suspicion is then some kind of mechanical shock. Could be caused (guessing) by sudden thermal shock (different crimping or enlargement), different sudden speed changes (hanging) by start/stop, different kind of shocks in fluid (start, stop and/or waterhammer), drying up giving start-up disturbances etc.