We have a system that has a polished aluminium surface pressed onto a smooth copper coated ceramic one.
Because of differential thermal expansion the aluminium will spread radially and pull the ceramic into tension.
We think we need to have a low enough coefficient of friction between the two...
Another piece of information has come to light. It appears we have copper in the cooling system. The black deposits may be cupric oxide.
It is possible we have release of Cu2+ ions into the water which is causing a reduction reaction at the SS interface, possibly there is Fe contamination on the...
hello moltenmetal,thanks for your reply.
The fittings we are using are 316L stainless. We have a stainless manifold with welded bosses, each with internal thread and a flat face.
The first part of the fitting is screwed into this with a Dowty washer to seal. This joint is not leaking.
The other...
We have a cooling system problem where 60 degree cone type fittings are leaking. We have systems that do not leak, and the common factor appears to be Ethylene Glycol in the systems that leak. The coolant is de-ionised water at about 0.5uS/cm.
I have heard that both de-ionised water and glycol...
Thanks for those replies.
The flow is laminar (Re ~700) but the linear velocity is about 2.3 m/s.
We are about to investigate why 2 of 9 seem to be affected, it is possible there is a subtle geometry / flow difference between them.
One option is to put a high resistance discharge path, such...
On the theme of static discharge hazards, we have another problem that is related.
We are transporting a mineral oil in silicone rubber hosing and are experiencing static build-up.
The hose joins two stainless steel fittings which are earthed, but the static is discharging from the middle of...
