Shawn Forsythe
RIP
Free? Heck no. I say it costs plenty!
"Free Flow"
- Thread starter Shawn Forsythe
- Start date
Ron Werner
Member
the only way I could see it being helpful is when the engine slows down a bit just before the relief valve kicks in, the ff system would keep rpm's up. WOuldn't want to be bleeding too much though.
I have a valve to my sink I sometimes forget to close, its a 1 1/4" hose, and I can feel the difference at the wand. Much better when its closed
I have a valve to my sink I sometimes forget to close, its a 1 1/4" hose, and I can feel the difference at the wand. Much better when its closed
bob vawter
Grassy Knoller
ok shawn...i'll bite!
Why would one put on a relief valve...when everyone KNOWS...
SUCK IS GOOD???
Why would one put on a relief valve...when everyone KNOWS...
SUCK IS GOOD???
truckmount girl
1800greenglides
With an underpowered motor that can't handle high lift, a "free flow" system (definition of free flow system: holes drilled in a cap one at a time while the TM is on. You stop drilling holes when the engine runs in it's power curve while working) can prevent bog, and will/can work fine if you always use the same system (ie: length of hose run, diameter of hose, wand, glide, etc.), beyond those two scenarios it's useless and detrimental to the performance of the system.
Take care,
Lisa
Take care,
Lisa
Shawn Forsythe
RIP
Actually the Vacuum Relief Valve's true intended purpose is to guard the blower, engine, coupling device, and wastetank from excessive loading that might occur if the plumbing were restricted beyond the tolerances of these system components.
Contrary to some people supposition, it serves not to govern the lift or CFM, but to guard against too high a loading, for which the lift level might shape, determine and/or indicate.
Since most spring loaded relief valves can't help but open slightly on progressive loading of the spring mechanism, one inherent flaw is CFM-bypass, or loss, at lift levels below the desired set threshold.
Ideally, your vac relief valve operates only as a safety, opening only when the lift level reaches the "danger zone". At all other times, the valve would remain completely closed, permitting total CFM production through the extraction tool (wand). Of course, this is incumbent upon the tool and hose permitting the entire CFM production to be moved through the effective orifice of such.
Typically, the only time where intentional leakage would be desired is if the tool cannot pass enough of the CFM generated when the tool is in contact with the textile being cleaned (carpet). For this, you would possibly want a throttled opening to permit CFM bypass, but only at, or near the wand. This is so the introduction of the bypassed air flow can be effectively used to "push" or conduct the extracted water through the hose and into the waste-tank. The very last place you would place the controlled leak is at the wastetank itself. The only other time a controlled leak is desired, is if the wand becomes tractioned to the carpet, such that proper wand stroking is difficult or laborious. Again, the controlled leak (provided the safety relief valve is of a positive shut-off type), is at or near the wand.
Up to this point, we've only seen two types of safety relief valves that create positive shut-off. The Kunkle/Bayco mechanical solution and the electro-mechanical "SOVC". Both work to do the same thing, but by slightly different means. The disadvantages of the SOVC compared to the Kunkle/Bayco is that the SOVC besides being much more expensive, is more complex engineered solution and prone to failure. The SOVC has also been patented for our industry, with the sole supplier commanding a hefty premium for his unique protected product. Whereas the Kunkle/Bayco valves were specifically designed to be the simplest wholly mechanical means of safety relief for pneumatic vacuum systems handed down from the petroleum and vacuum recovery truck industry.
Contrary to some people supposition, it serves not to govern the lift or CFM, but to guard against too high a loading, for which the lift level might shape, determine and/or indicate.
Since most spring loaded relief valves can't help but open slightly on progressive loading of the spring mechanism, one inherent flaw is CFM-bypass, or loss, at lift levels below the desired set threshold.
Ideally, your vac relief valve operates only as a safety, opening only when the lift level reaches the "danger zone". At all other times, the valve would remain completely closed, permitting total CFM production through the extraction tool (wand). Of course, this is incumbent upon the tool and hose permitting the entire CFM production to be moved through the effective orifice of such.
Typically, the only time where intentional leakage would be desired is if the tool cannot pass enough of the CFM generated when the tool is in contact with the textile being cleaned (carpet). For this, you would possibly want a throttled opening to permit CFM bypass, but only at, or near the wand. This is so the introduction of the bypassed air flow can be effectively used to "push" or conduct the extracted water through the hose and into the waste-tank. The very last place you would place the controlled leak is at the wastetank itself. The only other time a controlled leak is desired, is if the wand becomes tractioned to the carpet, such that proper wand stroking is difficult or laborious. Again, the controlled leak (provided the safety relief valve is of a positive shut-off type), is at or near the wand.
Up to this point, we've only seen two types of safety relief valves that create positive shut-off. The Kunkle/Bayco mechanical solution and the electro-mechanical "SOVC". Both work to do the same thing, but by slightly different means. The disadvantages of the SOVC compared to the Kunkle/Bayco is that the SOVC besides being much more expensive, is more complex engineered solution and prone to failure. The SOVC has also been patented for our industry, with the sole supplier commanding a hefty premium for his unique protected product. Whereas the Kunkle/Bayco valves were specifically designed to be the simplest wholly mechanical means of safety relief for pneumatic vacuum systems handed down from the petroleum and vacuum recovery truck industry.
bob vawter
Grassy Knoller
HEY I GOT AN IDEA..
How 'bout if my WAND was the relief valve......
cuz you sure as hell ain't gonna bog my V8 down an' you ain't gonna cave my Genie tank in....AND i NEVER have had a clutch or a blower failure yet......so
ya i run in lockdown mode...
let the bashin'....begin!
How 'bout if my WAND was the relief valve......
cuz you sure as hell ain't gonna bog my V8 down an' you ain't gonna cave my Genie tank in....AND i NEVER have had a clutch or a blower failure yet......so
ya i run in lockdown mode...
let the bashin'....begin!
truckmount girl
1800greenglides
That small leak at the wand that Shawn described is why there is supposed to be a very slight gap on the ends of most glides. It actually aids extraction.
As Shawn said, relief valves are there to keep you from losing engine RPM and power through the motor bogging excessively and/or to keep the waste tank from imploding.
Free Flow is a crude version of vac relief at best. It is "tuned" and then cannot be adjusted for changes in the system which may increase or decrease lift and thus bog or over-relieve the system. Both of which cases will hurt performance.
Take care,
Lisa
As Shawn said, relief valves are there to keep you from losing engine RPM and power through the motor bogging excessively and/or to keep the waste tank from imploding.
Free Flow is a crude version of vac relief at best. It is "tuned" and then cannot be adjusted for changes in the system which may increase or decrease lift and thus bog or over-relieve the system. Both of which cases will hurt performance.
Take care,
Lisa
bob vawter
Grassy Knoller
come on Lisa...are you sayin' that SUCK is a BAD THING.......
bob vawter
Grassy Knoller
truckmount girl said:
what if neither is applicable?
Shawn Forsythe
RIP
truckmount girl said:
Ahh, yes. A unique solution to a design defect. One case where two wrongs make for a half-assed get-you-by, right.
Sort of the same reasoning behind using volumes of red goop. If the designer can't make things fit, fill the gaps with goop.
Shawn Forsythe
RIP
bob vawter said:
Whiskey Tango Foxtrot?
If you find that you have enough leak on a particular carpet, that a vac relief valve would not serve a pupose, all you have determined is that you have enough leak for that situation.
You still need a relief valve for when that does not occur, or when the unexpected happens, and lift rises to "danger levels" for the components, including the blower itself, which does have a "redline" level (in most cases 15" HG). Read the first line of my long post.
truckmount girl
1800greenglides
Bawb,
It's okay to not use relief if your system can handle it, but it puts needless strain on components. Eventually something will give....unless you have leaks you aren't aware of.
Take care,
Lisa
It's okay to not use relief if your system can handle it, but it puts needless strain on components. Eventually something will give....unless you have leaks you aren't aware of.
Take care,
Lisa
Hoody
Supportive Member
Because you lessened the restriction on the line. The relief valves do put a bit of restriction on the line itself. The purpose of them is for when you reach the max, that it opens the relief valve.
Do this, get a big straw. Start sucking on the one end, and then stick your finger on the other. Eventually if you're able to; the straw will start imploding, remove your finger and that force will stop.
Fred,
The only thing you did was increase the CFM's. When you increase CFM's by adjusting the spring valve you're giving up lift. Increase the lift you're giving up CFM's. Adding bigger hoses allows you to keep CFM's. It will initially lower the amount of Hg's when the machine isn't under load, giving you more availiable lift before the relief valve kicks in.
If you look at your vac gauge and your idle Hg reading is very close to your under load Hg reading, you have something somewhere restricting. It could be a hose issue, silencer/muffler, relief valve, or something else in the plumbing(filters, ect)
Do this, get a big straw. Start sucking on the one end, and then stick your finger on the other. Eventually if you're able to; the straw will start imploding, remove your finger and that force will stop.
Fred,
The only thing you did was increase the CFM's. When you increase CFM's by adjusting the spring valve you're giving up lift. Increase the lift you're giving up CFM's. Adding bigger hoses allows you to keep CFM's. It will initially lower the amount of Hg's when the machine isn't under load, giving you more availiable lift before the relief valve kicks in.
If you look at your vac gauge and your idle Hg reading is very close to your under load Hg reading, you have something somewhere restricting. It could be a hose issue, silencer/muffler, relief valve, or something else in the plumbing(filters, ect)
Hoody
Supportive Member
P.S.
If your vac gauge reads nothing, but when you put your hand over the vac hose and it reads you probably have a bad waste tank seal, or you left the dump valve open.
I thought I blew the blower on the steam genie. Looked at the valve on the back of the truck and it was open. DOH!
If your vac gauge reads nothing, but when you put your hand over the vac hose and it reads you probably have a bad waste tank seal, or you left the dump valve open.
I thought I blew the blower on the steam genie. Looked at the valve on the back of the truck and it was open. DOH!
Hoody
Supportive Member
Then you already should have known the answer to the question. lol
There could be some benefits, indeed. But on a machine of Nick's design with the small blower and engine that is where he is flawed. Well besides the goop, of course.
lolThere could be some benefits, indeed. But on a machine of Nick's design with the small blower and engine that is where he is flawed. Well besides the goop, of course.
Shawn Forsythe
RIP
FCC said:
Why was there water in the hoses if you were adjusting, and not cleaning?
bob vawter
Grassy Knoller
OK...I CONFESS.....
on my relief valve...i cover all the holes BUT ONE wit several pieces of duct tape.....
gotta breath....some!
on my relief valve...i cover all the holes BUT ONE wit several pieces of duct tape.....
gotta breath....some!
truckmount girl
1800greenglides
Shawn Forsythe said:
Ahh, yes. A unique solution to a design defect. One case where two wrongs make for a half-assed get-you-by, right.
Sort of the same reasoning behind using volumes of red goop. If the designer can't make things fit, fill the gaps with goop.[/quote:2dq58p5i]
Aint it the truth.
Take care,
Lisa
truckmount girl
1800greenglides
FCC said:
Lift pulls the water out of the carpet/pad, cfm moves it down the hose...unfortunately they are generally inveresely related. That is why a slot or hybrid glide can pull more water out of the PAD of a carpet (flood jobs) than a hole, but a hole gets them drier for normal cleaning. The slot or hybrid glide communicates more lift, the hole allows more cfm.
By actuating your spring relief valve, you allowed your machine a nice, big gulp of cfm and moved all the water that was accumulated in your hoses through very efficiently...however, you just lost lift at the wand and won't be drawing as much out of the carpet. The longer the hose run, the more dramatic this would be. The idea is to have a good balance of lift and cfm for each job. A live/dynamic relief (spring, kunkle, bayco, sovc) properly functioning, accomplishes that. A static system (no relief, free flow, leaky system) does not compensate and will be less efficient on all but the narrowest margin of situations.
I've no doubt that because of some design flaws, system configurations, questionable modifcations, etc. certain machines can benefit from a leaky system (whether the leak is intended or accidental) but in general a relief should be dynamic not static.
Take care,
Lisa
truckmount girl
1800greenglides
There is actually a lot of good info in this thread....do any of the participants have a problem with me moving it to the Clean Room?
Shawn??
Take care,
Lisa
Shawn??
Take care,
Lisa
bob vawter
Grassy Knoller
maybe you could say it started...
ONLY IN THE RUBBER ROOM?
ONLY IN THE RUBBER ROOM?
I was under the assumption that high CFM's do the actual drying of the carpet.
The theory of high lift only pertains to extracting massive amounts of water as in water damage situations.
By drilling a hole into the sides , just above the slot on my POS Castex wand I've eliminated lock down and increased air movement to keep things flowing smoothly.
The theory of high lift only pertains to extracting massive amounts of water as in water damage situations.
By drilling a hole into the sides , just above the slot on my POS Castex wand I've eliminated lock down and increased air movement to keep things flowing smoothly.
Shawn Forsythe
RIP
Walrus said:
But at least you haven't put a leak on your wastetank, "Free-Flow-Style", and completely destroyed your extraction potential.
G
Guest
Guest
truckmount girl said:
I'm guessing baWB has all kinds of leaks and dribbles, and doesn't trust his farts....the epitome of "FreeFlow"
bob vawter
Grassy Knoller
no dribbles but i HAVE had a coulpa leaks and yes NEVER trust a fart....ever!
Dolly Llama
Number 5
truckmount girl said:
help me understand that one
There's no water in a blower.
how does introducing an air leak (gulp of air) down stream of water/air in hoses(at blower relief vavle) increase CFM in the hose?
it would seem just the opposite , cause you haven't increased anything in the hose.
The only thing that happened was decreased lift
my thoughts why...the man on the wand happened to lift the wand coincidentally at the same time Fred pushed in relief valve.
OR..
the original lift caused lock down and when he decreased lift, it decreased lock down and CFM thru the hoses increased.
OR..
the belts were slipping a LOT and when he decreased HG, the blower started spinning faster and increased CFM
..L.T.A.
Shawn Forsythe
RIP
Capt'n Marvel said:
That would be my vote.
Dolly Llama
Number 5
Shawn Forsythe said:
That would be my vote.[/quote:2wvctqep]
yep
Fred should of given us the "belt squealing" tid bit earlier
..L.T.A.
Bob Savage
Member
I will disagree with almost everyone here because I have been using the "free flow" design for 16 years, and it does work. It works by lessening the load on the motor, and the blower. It uses less fuel, and causes less strain on the machine components. Belts last longer, everything lasts longer.
There is no gain in CFM using the free-flow setup, but you are also NOT losing CFM. A properly designed vacuum system will produce more vacuum than the hose can possibly use in the first place. You do drop some lift with free-flow, but not enough to effect water recovery at the wand.
Our TM uses a #45 blower, over-driven to 4150 RPM, going to 2 separate recovery tanks, with each tank having it's own 2" vacuum hose going to the TM panel. This makes the internal plumbing of the TM 4 to the front of the machine (2 separate 2" vac hoses). On the discharge side of the Blower (2.5" NPT), we have a 2.5" to 3" bell increaser, going to a 45º bend, then into another 45º bend to a 3" to 4" bell increaser, and finally into a Stoddard 4" NPT silencer. When running a single wand, we put a foam block into one of the 2" hose barbs to allow that amount of air to "leak" (free-flow), or, we run 4 to the door. With 4 to the door, there is no free-flow. I know you are laughing at the foam block thing, but it allows the correct amount of air to "leak".
When we run dual wands (which is almost every job), the free-flow becomes the 2 separate end-of-hose connections going to each wand - there is no open free flow device back at the TM.
So, anyone using dual wands, is using the free flow design whenever one of the tools is off the carpet or upholstery, whether they are aware of that or not.
There is no gain in CFM using the free-flow setup, but you are also NOT losing CFM. A properly designed vacuum system will produce more vacuum than the hose can possibly use in the first place. You do drop some lift with free-flow, but not enough to effect water recovery at the wand.
Our TM uses a #45 blower, over-driven to 4150 RPM, going to 2 separate recovery tanks, with each tank having it's own 2" vacuum hose going to the TM panel. This makes the internal plumbing of the TM 4 to the front of the machine (2 separate 2" vac hoses). On the discharge side of the Blower (2.5" NPT), we have a 2.5" to 3" bell increaser, going to a 45º bend, then into another 45º bend to a 3" to 4" bell increaser, and finally into a Stoddard 4" NPT silencer. When running a single wand, we put a foam block into one of the 2" hose barbs to allow that amount of air to "leak" (free-flow), or, we run 4 to the door. With 4 to the door, there is no free-flow. I know you are laughing at the foam block thing, but it allows the correct amount of air to "leak".
When we run dual wands (which is almost every job), the free-flow becomes the 2 separate end-of-hose connections going to each wand - there is no open free flow device back at the TM.
So, anyone using dual wands, is using the free flow design whenever one of the tools is off the carpet or upholstery, whether they are aware of that or not.
truckmount girl
1800greenglides
Assuming that the wand was in the same position before and after he actuated the relief valve, the reason why actuating the relief would help clear the hoses faster is it creates a "draw" further down the line. Even the gap in a glide is BEHIND the carpet/glide interface, the engineered gap adds cfm which creates an additional draw on the carpet.
That is why free flow works in a very specific margin, especially with a motor (or coupling system) that is too small and can't handle the load that restriction puts on it.
Free flow works....it is just not the most performance efficient way to do the job. A balanced system with good components would suffer from the constant leak and can take advantage of the lift created: flood work, long hose runs, dual wanding situations all require a setup capable of handling high lift.
A dynamic relief system relieves when lift gets too high.....introducing more cfm into the picture, a static system, like free flow, cannot relieve more at higher lift and less at lower lift, so it is only optimal at one given setting, the setting it was tuned for. At higher or lower loads it fails to be optimal.
However, having had a TM myself that had an underpowered motor, poor coupling alignment and a weak tank, I can say free flow would have been ideal for that unit. As long as there are poorly designed/built units out there free flow will always have a place...you can bet your autographed Dale Earnhart football on that!
Take care,
Lisa
That is why free flow works in a very specific margin, especially with a motor (or coupling system) that is too small and can't handle the load that restriction puts on it.
Free flow works....it is just not the most performance efficient way to do the job. A balanced system with good components would suffer from the constant leak and can take advantage of the lift created: flood work, long hose runs, dual wanding situations all require a setup capable of handling high lift.
A dynamic relief system relieves when lift gets too high.....introducing more cfm into the picture, a static system, like free flow, cannot relieve more at higher lift and less at lower lift, so it is only optimal at one given setting, the setting it was tuned for. At higher or lower loads it fails to be optimal.
However, having had a TM myself that had an underpowered motor, poor coupling alignment and a weak tank, I can say free flow would have been ideal for that unit. As long as there are poorly designed/built units out there free flow will always have a place...you can bet your autographed Dale Earnhart football on that!
Take care,
Lisa
