SS Conical valve repairing

[sancat]

We have received some stainless steel valves from a medical specialties laboratory to repair their leaking. They are similar to spherical valves (the ones that have a steel ball with a hole and they turn 90 degrees to open or close), but instead of a ball these valves have a truncated cone.
We thought it was a piece of cake, just have the female and male cones rectified (both are stainless), and verified they were so with Prussia’s blue. We did it. But no matter what we did, they leaked.
Since I have not found them on the web I am thinking that this is a local invention, which does not work, or they exist but they have been “repaired” in the past changing them in some way.
Pressure is very low, perhaps 8 feet of water column, and liquid is very thick (cough medicine)
Does anyone know their name, and have any ideas on how to prevent leaking?
Do they need a spring to push down the cone?

 

[sunflake]

Depending upon the packing arrangement at the top of the valve, and torque required to operate these valves, you might try to live load the plug with bellville washers.

 

[sancat]

Sunflake,
Thanks, I thought no one knew this valve.
When we found it, it had a Teflon cone, which seemed to be non original. The maintenance manager of our client told us that he remembered that the original valve had Stainless cone. However our SS cone is not working and now I am having second thoughts about the material that should be used for the cone. Our problem is that if we use to little pressure, the valve leaks, and if we use too much pressure, the cone adjust so hard on the female, that it cant rotate. The washers you suggest will help since the middle point between too hard and too loose, will be easier to find. I will try that.
By the way you do know what material should be used on the cone?
Thanks
sancat