vac relief settings

I have a chance to pick up a new kunkle valve from a local hardware store...it has been sitting on his shelf for a couple of years. I think I can get it for less than $60, but it is factory set at 16 in/hg instead of 15.

How important is that 15 recommendation really? Would a 13, 14, or 16 make any real difference to be concerned about? I've seen some people setting their machines at 17 inches, but I don't want to beat up my blower either.

I was just thinking that for the money, I would put it on the TNT and dump the foot valve. I see that Judson has moved away from the foot valve on their newest machines to a bayco or kunkle valve and I am thinking that it makes sense to follow. I like that you can find a foot valve anywhere local, but you still have to mod the spring tension, so running a kunkle would eliminate that....even though it probably will not affect the performance.

Hmmm Interesting to hear Judson now running B/K Valve, after preaching about it's worthlessness for normal hose runs.

But I'm not sure about 15 vs. 16 in.  I'd think the recovery tank would suffer before the blower, but that"s just an assumption?

I'd check the specs from the blower manufactures site for the max hg.

I thought it was odd that Judson started putting bayco valves on the C4 and I think the TNT is getting them now as well, after telling us that there was no benefit over the properly set foot valve.

I don't know if it really improved things, it was probably just to eliminate all the phone calls from people asking why that off-the-shelf foot valve didn't allow very good vacuum out of the box.

That root 45 is factory set at 15 inch max and my butler's tuthill 4007 is also at 15 inch max, but I wonder if that 16 inch would really cause any issues? I think most builders include a safety cushion into their designs, and that a blower is probably safe up to 17 inches plus.

milspec6 wrote:I have a chance to pick up a new kunkle valve from a local hardware store...it has been sitting on his shelf for a couple of years.  I think I can get it for less than $60, but it is factory set at 16 in/hg instead of 15.

How important is that 15 recommendation really?  Would a 13, 14, or 16 make any real difference to be concerned about?  I've seen some people setting their machines at 17 inches, but I don't want to beat up my blower either.

I was just thinking that for the money, I would put it on the TNT and dump the foot valve.  I see that Judson has moved away from the foot valve on their newest machines to a bayco or kunkle valve and I am thinking that it makes sense to follow.  I like that you can find a foot valve anywhere local, but you still have to mod the spring tension, so running a kunkle would eliminate that....even though it probably will not affect the performance.

Have you priced out that particular valve on the market. What's a going rate for it?

I haven't bought one for a few years but as I recall the last kunkle valve I bought cost me about $345.

I think I would buy that sucker just for the value.

keep it til you figure out your answer and if you can't use it, sell it.

To me anything around 14 inches is strong enough (don't do flood work maybe that would change my mind) but I'll take every bit of CFM I can get.

I love that howling CFM!

milspec6 wrote:I thought it was odd that Judson started putting bayco valves on the C4 and I think the TNT is getting them now as well, after telling us that there was no benefit over the properly set foot valve.

I don't know if it really improved things, it was probably just to eliminate all the phone calls from people asking why that off-the-shelf foot valve didn't allow very good vacuum out of the box.

That root 45 is factory set at 15 inch max and my butler's tuthill 4007 is also at 15 inch max, but I wonder if that 16 inch would really cause any issues?  I think most builders include a safety cushion into their designs, and that a blower is probably safe up to 17 inches plus.

16" will be over kill on your belts with that said you can open the kunkle and adjust the lift

Are the kunkle valves really adjustable? I thought they were factory set and sealed.

The temptation of this valve is killing me, but it will not have much value if nobody can use 16 inches with their machines.

look at the diagram
http://www.hurcotech.com/PDFfiles/OwnersManuals/HurcoVac_Manuals_2012/4.1Kunkle1.pdf

milspec6 wrote:Are the kunkle valves really adjustable?  I thought they were factory set and sealed.

The temptation of this valve is killing me, but it will not have much value if nobody can use 16 inches with their machines.

Looking at the one I have (but not in use), I think they're factory set and sealed. But only "sealed" by the small stainless cable crimped with lead, You know the type I bet?.................It makes it real obvious when the seal has been broken. But I believe once broken you could adjust the valve to whatever hg you want. Of course if you did that, I'd bet any factory warranty is gone, if there even still is one.

I can take a post a pic of what I'm talking aout if you want, just let me know.

Last time I investigated it,, knucle valves are set at 14, the difference with them is they don't open at all until it hits 14,

with regular relief valves they open slightly under just a little lift, and then all the way when it hits the max setting. So you always have a little air leak more or less. , but not with th knuncle

That's right, and why they're claimed to be an advantage........because you aren't 'leaking air' all the time

But they aren't all set to 14...

Because they pull hard all the way to the set point, so it would seem like even a valve set at 12 would be an improvement when using wand glides as you really never block off vacuum completely anyway.

I suppose there are negatives as well, but it sounds good on paper.

Milspec,
16 Hg is not going to hurt you.

SCCC wrote:Milspec,
16 Hg is not going to hurt you.

Right, it will Only hurt your blower or recovery tank..........Fixed your post Tom!

milspec6 wrote:Because they pull hard all the way to the set point, so it would seem like even a valve set at 12 would be an improvement when using wand glides as you really never block off vacuum completely anyway.

I suppose there are negatives as well, but it sounds good on paper.

I personally wouldn't want mine set to only 12. My uphol tool and wand have 12-10 hg respectively at 100' of hose, with air free flowing.

I'm not worried about my recover tank at all (that sucker is like a vault), but I don't want to destroy the blower. I don't think that 16 would really be a problem, but I probably should play it safe and stay conservative.

Pulling 12 in/hg on an upholstery tool out at 100 ft? Which tool are you running, I know my Sapphire isn't running that high.

DM2

Most Tm's don't hold 16 hg's on carpet, even running my PC L at 3250 rpms stock is 2600 rpms on most resi carpet it only will hit @ 13 max most of the time it stays around 10-11 hg's.
This is why they can get away with a 20 hp kohler with a #4 blower and a pump.
The only time I have ever heard my motor even show any signs of hard work is on a CGD carpet where you get a real solid lock on the carpet, that was with out a glide. When we ran a glide it was @ 13 Hg's. My vac is set at 16 Hg's on my legend and has been that way going back to Joe and I, gotta be 5-6 years ago.
Guys that say they are " HOLDING" 16 Hg's with # 3-4 blowers I have a hard time believing it. Yes you can block the hose and get it but the wand leaks too much air to maintain it.
Just look at how much vac drops with just a little bit of air leaks due to cuffs, tank gasket, filters, anything on the hose run.
I set my vac that high because the spring type leak at the getgo, even when I crank the spring down it will still hold a piece of plastic to the little circle of holes because it is leaking air.

I cranked my vw the other day to @ 20 and broke my pulley...ugg. I think the belts would give away befor you imploded a tank, well at least the tanks I have they are full of bracing it would take a lot of vac to cause damage to them, belts would over heat, or in my case the pulley broke.

SCCC wrote:Most Tm's don't hold 16 hg's on carpet, even running my PC L at 3250 rpms stock is 2600 rpms on most resi carpet it only will hit @ 13 max most of the time it stays around 10-11 hg's.
This is why they can get away with a 20 hp kohler with a #4 blower and a pump.
The only time I have ever heard my motor even show any signs of hard work is on a CGD carpet where you get a real solid lock on the carpet, that was with out a glide. When we ran a glide it was @ 13 Hg's. My vac is set at 16 Hg's on my legend and has been that way going back to Joe and I, gotta be 5-6 years ago.
Guys that say they are " HOLDING" 16 Hg's with # 3-4 blowers I have a hard time believing it. Yes you can block the hose and get it but the wand leaks too much air to maintain it.
Just look at how much vac drops with just a little bit of air leaks due to cuffs, tank gasket, filters, anything on the hose run.
I set my vac that high because the spring type leak at the getgo, even when I crank the spring down it will still hold a piece of plastic to the little circle of holes because it is leaking air.

That is how I viewed it as well, I've never seen my butler over 12 running a wand...even with the relief spring cranked all the way down. I can see it if the wand didn't have a glide that it might run all the way up, but not under my normal conditions.

I think that a relief valve that doesn't leak from the start (kunkle or bayco) really makes sense...regardless if the setting was 12-16 in/hg as you will probably never get very high anyway.

Sorry to hear about the pulley, but at least we know that other things will fail before the blower. I think I am going to try the kunkle valve.

Go for it, I think you will be happy with it. At least you know you will be getting most of the vac where it belongs....at the wand slot !!!

Be interesting to see the test numbers between the foot valve and K valve.....I'm sure the K's numbers would be better, but really by how much?

SCCC wrote:I cranked my vw the other day to @ 20 and broke my pulley...ugg. I think the belts would give away befor you imploded a tank, well at least the tanks I have they are full of bracing it would take a lot of vac to cause damage to them, belts would over heat, or in my case the pulley broke.

What do you think would break first on a direct driven unit?

Davey Cracker wrote:

SCCC wrote:I cranked my vw the other day to @ 20 and broke my pulley...ugg. I think the belts would give away befor you imploded a tank, well at least the tanks I have they are full of bracing it would take a lot of vac to cause damage to them, belts would over heat, or in my case the pulley broke.

What do you think would break first on a direct driven unit?

On a butler, it would be the clutch. I think the double belts would be enough to survive the stress, but not that clutch.

Davey Cracker wrote:Be interesting to see the test numbers between the foot valve and K valve.....I'm sure the K's numbers would be better, but really by how much?

If the foot valve was set properly (stiffer spring and tuned), there probably would not be a lot of difference. At least Les has been concluding that for years, but how many get those foot valves set up properly?

It is just so convenient to install a valve factory set to the right limit rather than having to modify or adjust a lesser relief valve. Even if it didn't make a big difference, at least I would know that my vac was reaching its full potential under real-time operation.

milspec6 wrote:
If the foot valve was set properly (stiffer spring and tuned), there probably would not be a lot of difference.

Is there any other way? .....not for me, but I see what you are saying.

milspec6 wrote: At least Les has been concluding that for years, but how many get those foot valves set up properly?

I've got one here, right spring and set for a max of 15 hg when hose is blocked off.

Just an FYI...I was cleaning a low pile wool rug today and just as a test, locked down the wand on it and checked my gauge on TM, it was just a bit over 13!