How To Clean Reed Valves On Air Compressor
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- Poppet valves? To fit to an air compressor as old reed valves are shot?
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Poppet valves? To fit to an air compressor as old reed valves are shot? Poppet valves? To fit to an air compressor as old reed valves are shot?
So the reed vales in my compressor are stuffed. Can't find new ones as the company is not longer in business.
I new pump would be the go, but are like $800AUD to suit 5hp 3phase motor, ouch.
So I'm thinking that I could buy 4 poppet valves and just plumb them into the intake and exhaust ports on the cylinder head. Have them hanging on the outside of the head.
This would work.......?
Peter
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Why not just make new reeds?
They're usually nothing more than spring steel sheet cut to the right shape.
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Poppet valves have to be cam driven like in an engine so their motion and timing correpond to the pumping behavior needed for the equipment to function. Poppet valves have too much mass to cycle by differential air pressure. Another point is "head space". A replacement valve arrangement that leaves significant unswept volume lowers volumetric efficiency. Unexhausted air rebouncs between TDC has to expands enough from piston travel for the cylinder to draw ar.
Reed valves aren't hard to make or repair.
Or: if you look though the existing valves as replacement parts I'm quite sure you can find something close you can modify to fit.
Or you can spring for a new compressor pump.
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Well I did go and buy some shim stock to make some more reeds. But I gave up as they are not spring type steel and seem to be too soft.
If I could find some spring steel stock in 0.37mm thick (0.010") It would be worth giving a go.
If I could find a website with dimensions of similar sized reed valves that would also be a way around it, but as yet I have not been able to find a website with dimensions on reed valves and prices etc.
And I tried to cut the shim stock into strips using a guillotine, and it just folded the stuff, not cut it....But the paper guillotine did the job lol. I guess spring steel would cut properly in a sheet metal guillotine?
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Try looking for 1095 Blue Tempered Steel Shim Stock, .010 in. is a very common thickness. In the USA its available in sizable sheets for little money. It's a commodity, you can't access the OEM sources.
Sealing is job #1 for a reed valve, it must be flat. Shearing (guillotine?) is the wurst way to make a good reed valve in one off quantities, it distorts the edges and will compromise the seal. The trick to making successful reed valves is flatness and absolutely no local edge distortions.
Don't know the shape you need. Some are simple rectangles and they get all the way into flower shapes. If you've never done it before a conservative approach is sometimes a good path to follow.
Step away from the shear (and never let on you used the paper shear
).You're trying to save money but the trade for it will be craftsmanship. You can't quick and dirty a good reed valve of any configuration. Flat! No distortions! No residual edge stresses or stress risers. You must accomphish with one part out of the gate what the manufacturer did for mass produced parts. He knew the problem better than you will ever know.
A one off method is to make matching metal clamp plates with perimeters of the shape of the part you need, clamp the shim stock between them and reduce the workpiece to size between them using abrasive means.
The edges should be rounded and polished or cracks and failure are in your near future.
Doing a .010 reed valve freehand isn't a good option.
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i'd just find a dealer and use any reed valve from any compressor company.
worst case would probly be drillin' a couple little holes to match yours
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Yeah I understand the cracking etc and the flatness with the valves. Tell me this, the old ones that I pulled out were bowed. Is this normal? or does that mean they are cactus?
I just watched a video using a simple 12 car battery charger and etching the parts.....part stays dead flat then. I do have a mate that has an abrasive waterjet machine. I dare say that would make short work of the parts.
They are basically shaped like long feeler gauges. One is say 1/2" wide by say 5" and the other is very similar except it has a rounded or radius ends.
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Most reed valves that I've seen generally have a slight bow towards the seat, or there is some other arrangement to provide some preload on the seat to keep things sealed.
The usual failure mode of reed valves is wearing out the seat / developing wear on the reed itself causing leakage or the number one cause: They simply crack in half.
DaveE has the material angle covered. Spring steel sheets can be bought from any industrial supply here. Hopefully, that's the case on your side of the pond.
- You answered your own question, order some .010'' feeler guages and cut them to fit.
Originally Posted by Apples 
They are basically shaped like long feeler gauges. One is say 1/2" wide by say 5" and the other is very similar except it has a rounded or radius ends.
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first couple times i ordered new reeds for my quincy they were 2 and 3 fingered affairs quite fancy.
then someone figured out it cost half as much to make them single, from then on they came in as described. feeler gauges with holes.
i would say they should be dead flat not bowed
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What's the name of the compressor?
I can google it for you, just need the compressor name.
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You won't find parts for it ( I say this as a challenge, cause I hope you do).
Australian made unit, but might have had similar components from other compressors.
Consolidated Pneumatic CP5 5.5hp 4.0KW 7.3Amps CFM???
On another note, I cleaned up the heads and the valve plate assembly, washed the reed valves down with metho and a scotch pad. The reed valves look to be coated funny. They are shinny like stainless but have a flicker of sparkle through them that look a disco ball.
So I cleaned the reed all up, cut new gaskets and put it all back together with a little (read little) bit of gasket goop.
Plugged her back in and turned it on and it sounded like it was pumping more/louder/harder. When I put my hand over the intake it was sucking much harder than before.I'm thinking great, but then the pressure would not build up at all......argh. Where as before I touched it it would at least build up to pressure. Always the way, I made it worse.
Unless I have put the parts in backwards, which I know I haven't what has happened? And now when I stop the compressor the air that it does have built up leaks out of the intake port badly.
I can only think that when the reeds were dirty they had gummed up oil hole marks, this must have sealed better against the port holes. Since I washed that off it may not longer be sealing. You can see the round oil makes in the photos below.
1. Are the reeds supposed tho have that bend in them?
2. Maybe the valve plate needs a slight surface grind too, when I or I fI can get new valves?FAD- Free Air Delivery
If a new compressor say 25cfm has a FAD of say 18cfm at 90psi, this would mean that an empty tank with just the motor and pump running would push out the FAD of 18cfm at 90psi?
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Perhaps the unloader is acting up?
Various types of unloader are possible, and a check valve may be giving you fits, also.
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Well all there is, is two pipes from the exhaust ports straight into the tank. There is no one way valve. I assumed the reed valve would stop back pressure?
Are feeler gauges hardened steel or spring steel? I 'm thinking of using them now and cut to length with a cut off disc. Have it squashed between two bits of sheet metal and cut through the whole lot.
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Find a local machinery repair depot, and someone would most likely give you hints, referral to a vendor, etc.
The check valve may be the fitting that goes into the tank.
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if it were me...
i would carefully clean and inspect everything you have, the head
the reeds, and retainers, the top of the pistons etc.then i would carefully work on making sure the head surfaces that the reeds work against is flat, very flat and smooth.
i would then work on carefully tweeking those reeds to make the flat
and to where they can seal properly, it might take a bit of careful bending but i bet you can get them to lay flat again. you might even want to lap them smooth by whatever means you have available.then carefully reassemble and it should work.
if the reeds are not broken, cracked or damaged irreversibly the thing ought to be able to be put right again with a little careful work.
bob g
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mobile bob
yep I did everything except for bending them to make them flat. SO I dunno if they are supposed to be flat or have a curve in them. I guess the bend in them is there to have positive contact so that it is tensioned in the valve seat area. Maybe if it was dead flat it would flop and wobble around?
I think but not sure that if it is supposed to be bent, the fast rushing air would suck the reed up to make a proper seal on each stroke.
I will see if it has a check valve, and what condition it is in.
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i'm not quite familiar with that exact reed valve system, but it has been my experience that reeds need to lay flat, or damn near so.
rushing air is not sufficient to close them tightly so they will seal, especially a slow churning thing like a compressor.the check valve into the tank actually doubles as another reed valve for the discharge of the compressor, having a good check on each cylinder would probably get the discharge side pumping properly, and the thing will go back to work again provided the suction side is sealing properly.
if you can hold your thumb over the discharge of either cylinder while rotating the compressor by hand, you might well hear the air bleeding back through the reeds on the suction side out the air cleaner.
conversely if you thumb feels like it is being sucked in on the suction stroke you got discharge reed problems
personally i still think the reeds should be flat, and there ought to be some means of keeping them within contact so they don't just flutter around loose.
wish i had it here on my bench
bob g
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Okay so this is all that I have from my pumps outlet to my tank input. See photos below.
No check valve / one way valve. Just a standard copper flared fitting to a long bit of copper pipe with holes and a squashed end.
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That is what the typical in-tank check valve looks like:
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How To Clean Reed Valves On Air Compressor
Source: https://www.practicalmachinist.com/vb/general/poppet-valves-fit-air-compressor-old-reed-valves-shot-211415/
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