Improving Wear Resistance of Valve Rods
Improving Wear Resistance of Valve Rods
(OP)
Hello all,
This is my first post here, proud to be doing so. I've been googling through this site this afternoon, and it's been very informative.
I'm working with a metered mix system with a worst-case kind of application, dispensing an aluminum oxide filled thermal compound. The compound itself is insanely abrasive, and I've been trying to improve several parts of it.
The cup seals it originally came with were made of EPR (god knows why), so those have been swapped for polyurethane (I should be seeing some improvement in wear resitance), I'll be stepping up to UHMW Polyethylene with a steel spring if that doesn't work.
The next improvement on the list is replacing the valve rods in contact with the seals mentioned above.
As provided, they were stainless steel with some kind of superficial gold-colored coating. Completely inadequate in terms of wear resistance.
I did some drawings, and sent it out for quotes specifying fully case-hardened 8620 steel.
Was this a good call?
Is there a better option?
Take it easy,
Toby
This is my first post here, proud to be doing so. I've been googling through this site this afternoon, and it's been very informative.
I'm working with a metered mix system with a worst-case kind of application, dispensing an aluminum oxide filled thermal compound. The compound itself is insanely abrasive, and I've been trying to improve several parts of it.
The cup seals it originally came with were made of EPR (god knows why), so those have been swapped for polyurethane (I should be seeing some improvement in wear resitance), I'll be stepping up to UHMW Polyethylene with a steel spring if that doesn't work.
The next improvement on the list is replacing the valve rods in contact with the seals mentioned above.
As provided, they were stainless steel with some kind of superficial gold-colored coating. Completely inadequate in terms of wear resistance.
I did some drawings, and sent it out for quotes specifying fully case-hardened 8620 steel.
Was this a good call?
Is there a better option?
Take it easy,
Toby





RE: Improving Wear Resistance of Valve Rods
RE: Improving Wear Resistance of Valve Rods
The question mark has two meanings:
1. Have you considered it?
2. It's gold-colored is that what was already on the original?
RE: Improving Wear Resistance of Valve Rods
If it was TiN coating, and it was "superficial", then it must've been done by a bad supplier. But I agree, TiN or AlTiN is definitely a good option for wear resistance.
V
Mechanical Engineer
"When I am working on a problem, I do not think of beauty, but when I've finished, if the solution is not beautiful, I know it is wrong."
- R. Buckminster Fuller
RE: Improving Wear Resistance of Valve Rods
I think the decision then was, lets make it stainless steel for corrosion resistance (which, in our application, doesn't matter, the compound is silicone based, excludes air and moisture, and is pretty chemically friendly, at least as far as metal goes), and then coating them for wear resistance (which didn't work).
I think overall, perhaps replacing the seal material may have a bigger impact on the problem. If the seal is better, then there's less chance of material getting in and abrading the rods.
We'll see how expensive making these is going to be.
RE: Improving Wear Resistance of Valve Rods
RE: Improving Wear Resistance of Valve Rods
http://www.sulzer.com
RE: Improving Wear Resistance of Valve Rods
RE: Improving Wear Resistance of Valve Rods
Save water Drink Beer
RE: Improving Wear Resistance of Valve Rods
He recommended A-series steel fully hardened, with a note that 60-62 Rockwell C is attainable this way.
I'm comparing prices as far as that versus 8620.
RE: Improving Wear Resistance of Valve Rods
I have seen solid TiCN valves.
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
RE: Improving Wear Resistance of Valve Rods
Don
Kansas City
RE: Improving Wear Resistance of Valve Rods
If you use 8620, be sure to specify the case hardness and depth after grind so that all the case is not removed by finish grinding.
Ted
RE: Improving Wear Resistance of Valve Rods
We use solid ceramic plungers on a variety of PD pumps.
We have used Saturn Coatings on some on very tough problems.
http://www.saturnceramic.com/abrasion.htm
RE: Improving Wear Resistance of Valve Rods
http://ww
Ed Danzer
www.danzcoinc.com
www.dehyds.com
RE: Improving Wear Resistance of Valve Rods
- Ceramic Coating on steel
- Hard Chrome Coating on steel
- Fully hardened A-series steel
- Case-hardened 8620
- Solid Ceramics instead
- Alter design to change seal mechanics.
I think the first step is definitely to replace the seals with something tougher.
RE: Improving Wear Resistance of Valve Rods
Thank you all for your input.
RE: Improving Wear Resistance of Valve Rods