Tire inflators, quick comparison

[hoser]

Morr and EZ flate would be a lot more attractive if they weren’t so bulky when not in use. For that space savings I can deal with the increase in time and drop in convenience.

I agree, the morrflate/EZflate is quite bulky. But you can get even more cabin space savings with a ARB twin under the hood. The new brushless version is 33-50% faster than the old version. It'll run just one of the two compressors in a low voltage situation or when in need of redundancy. If you want the digital pressure switch, you can add it. Cost is certainly much higher but it's better in many ways.

 

[gaijin]

@Boston Mangler
The auto pressure is nice. But other, faster compressors have that feature too.

MORRFlate TenSix™ PSI Pro™ 12v Portable Compressor - Gen2 • MORRFlate

Set Your Pressure™! Air up a set of 35" tires from 10 to 40 psi in under 5min (when combined with a 4 Tire Hose Kit) 10.6 CFM dual cylinder compressor at 0 PSI 6.5 CFM at 30 psi 10-120 psi in Auto Mode 1-150 psi in Manual Mode Thermal Cutoff Switch & Purge Valve 80% duty cycle @ 0psi...

morrflate.com

I really do not understand the Note on the site selling that inflator:

Maybe I'm just having a senior moment, but how can running a compressor four times for a short duration shorten the duty cycle?

And the statement, "It just simply puts out too much air and is optimized for 4 tires at a time" makes no sense to me.

Enlightening comments?

TIA

 

[hoser]

Basically, It's a 10.6cfm compressor (@5PSI). The Schrader valve is limiting flow. Similar to if you were to inflate (4) of your kids pool toys and your face turns red. Your face would be LESS red if the pool toys had a 1" inflation valve like many air mattresses.

His words:
MORRFlate-Tyler

"Oh man... thats a huge topic that might be too much to type out... We just recorded an episode about this very thing on Snailtrail 4x4... it should be releasing tomorrow morning. I will try and remember to come back and post a link here... should be episode 451.
in short... it comes down to duty cycle. Compressors can either be "Low Pressure, High Volume" (think of an air mattress compressor... which works more as a special fan than actually compressing air to create pressure), or "high pressure, low volume" which is what all of our off road tire compressors are. ANd the higher the working pressure you need, the lower the volume it can do, due to backpressure pushing back on the compressor cylinders and valves while its compressing air and trying to send it down the line to your reservoir (whether that is a tank or a tire or whatever).

If you look at compressor stats, generally, their advertised CFM is measured at "atmospheric pressure" or zero psi. And, as the compressor gets higher in its working pressure, the CFM will drop. For instance, our TenSix compressors will do 13.5 CFM at zero pretty regularly, but that drops to about 10.6 CFM at 5psi (which is what we advertise at, because very few people are acutally using compressors in the offroad space below 5psi). At 20 psi, we are at about 6.5-7CFM. At 30 psi, we are at about 3.5-4 CFM, at 40 psi, we are at about 2.5-3CFM. and once you get above 100 we are at about 1.5-2cfm. That is because, the higher the working PSI, the more the compressor motor and cylinders have to work to overcome the pressure in your reservoir in order to continue pumping air into it. The harder a compressor works, the hotter it runs. Once a compressor runs too hot, it will either burn up wiring, motors, or gaskets and seals. Any good compressor will have a thermal cutoff switch that measures working temperature and shuts off the power to the compressor before it reaches that melting point (typically around ~200 deg f).

A "duty cycle" refers to a compressors ability to run longer before hitting that critical temperature. So, when you see duty cycles quoted or advertised they should all be based on a time frame. i.e. "50% duty cycle at 30min" which means the compressor should spend 15min off for every 15min it is on and running. In my opinion, the duty cycle of compressors should also be stated within a working PSI range... because the higher the PSI a compressor is working at, the shorter its duty cycle will be due to working harder.

When it comes to 1 tire vs 4 tires and why you want to be careful with some higher output compressors now a days... A tire's valve stem can only accept about 2cfm of airflow at a time. So if you are using a compressor that can output 5.5cfm, 6cfm, or 10cfm, through an orifice designed for 2cfm, you are going to create a big bottleneck of airflow, which causes higher working pressures on the compressor, and lower duty cycles. You can use our compressors to do one single tire, but because that back pressure ends up being so much, the duty cycle dwindles to about 2 min on, 15-20min off. So you dont want to do an entire vehicle doing 1 tire at a time with them."

That said, a lot of folks using these compressors and the numerous brands like it, one tire at at time. You can also add or change to a faster inflation valve, i.e Monster Valve.

 

[OregonLC]

Hadn't considered the benefit of the Cv of the schrader being effectively halved by splitting into parallel fill lines. Seems like a reasonable theory, assuming that the Cv of the schrader is the biggest restriction on the system. Is there data proving this out?

I built my own Morrflate once using 3/8 Flexzilla hose and their high-flow fittings and didn't find any appreciable decrease in fill times, only a bulkier hose set. So I went back to a single outlet hose.

 

[hoser]

The Schrader valve is the bottleneck with a high volume compressor. That's why when you seat the bead on new tires, you usually remove the valve core for maximum air flow. Try deflating two tires to 0 psi. Remove one of the valve cores. Do a timed test and see which tire has a higher pressure after 5 minutes.

 

[grinchy]

Since we're onto the topic of getting air out and in around the limitations of good ole' papa Schraeder

Apex RCV and RPV Fast Deflators

There's enough meat on this topic of Apex Deflators that it deserves its own thread. Screw on RCV (Rapid Connect Valve) Install / Replace valve stem RPV (Rapid Precision Valve) in std length (which should work with most OEM wheels) From the following discussion It's actually crazy timing...

forum.ih8mud.com

I can attest that airing up and down is faster with Apex valves. A lot lot faster to air down, and a bit faster to air up.

 

[OregonLC]

The Schrader valve is the bottleneck with a high volume compressor. That's why when you seat the bead on new tires, you usually remove the valve core for maximum air flow. Try deflating two tires to 0 psi. Remove one of the valve cores. Do a timed test and see which tire has a higher pressure after 5 minutes.

Seating a bead and inflation flow are two different things though, one is a burst transfer from a tank. The other is continuous work from a compressor.

If the schrader was the controlling factor in the system then it would mean my shop compressor would air up at the same rate as my twin, right? Both achieve the same pressure but the shop has a much higher flow at that pressure. So I don't think the system limiter is the valve. This isn't to say that an OBA compressor isn't a strained system that could benefit from relief. I'm just curious what the actual gain is (dual vs single)? 5%? 10%? 25%?

You're right on with your suggested experiment... I'd just rather read it than go out in the cold and run it myself. Was hoping there was some data proving it out. I see comparisons made from the competing multi-hose systems, but not single vs multi.

 

[bloc]

I agree, the morrflate/EZflate is quite bulky. But you can get even more cabin space savings with a ARB twin under the hood. The new brushless version is 33-50% faster than the old version.

I already have the brushed version on a slee bracket, and it’s awesome. All part of my strategy of keeping as much of the tools and “trail stuff” out of the cabin as possible.

Brushless sounds amazing but not worth the cost to upgrade given my stock sized tires..

 

[OregonLC]

@bloc did you get an engineering sample or are these available to buy?

Any dimensional changes?

 

[hoser]

Since we're onto the topic of getting air out and in around the limitations of good ole' papa Schraeder

Apex RCV and RPV Fast Deflators

There's enough meat on this topic of Apex Deflators that it deserves its own thread. Screw on RCV (Rapid Connect Valve) Install / Replace valve stem RPV (Rapid Precision Valve) in std length (which should work with most OEM wheels) From the following discussion It's actually crazy timing...

forum.ih8mud.com

I can attest that airing up and down is faster with Apex valves. A lot lot faster to air down, and a bit faster to air up.

AFAIK, those valves still use the Schrader style and so inflation should not be so different. Deflation is way different because it bypasses the valve core. But if you took a look at the Monster valve, the valve core is much larger.

Seating a bead and inflation flow are two different things though, one is a burst transfer from a tank. The other is continuous work from a compressor.

If the schrader was the controlling factor in the system then it would mean my shop compressor would air up at the same rate as my twin, right? Both achieve the same pressure but the shop has a much higher flow at that pressure. So I don't think the system limiter is the valve. This isn't to say that an OBA compressor isn't a strained system that could benefit from relief. I'm just curious what the actual gain is (dual vs single)? 5%? 10%? 25%?

You're right on with your suggested experiment... I'd just rather read it than go out in the cold and run it myself. Was hoping there was some data proving it out. I see comparisons made from the competing multi-hose systems, but not single vs multi.

Yes, not the same but related. Morrflate says the standard Schrader flows ~ 2cfm at 20psi. while their compressor is rated at 7.1cfm @20psi. Old ARB twin is rated at 5cfm @20psi. My 24V Oasis compressor is rated at 16cfm @100psi!

 

[bloc]

If the schrader was the controlling factor in the system then it would mean my shop compressor would air up at the same rate as my twin, right? Both achieve the same pressure but the shop has a much higher flow at that pressure.

You can only compare the shop compressor to a mobile inflator at the same PSI if the lines are also the same. And depending on how scientific you want to get, even the same diameter isn't enough, the hose itself can be a factor, due to potential differences in the material and surface of the inner wall of the hose that the air flows against.

I drive a fire truck for work and a big part of the traditional role of a driver is "pumping" at a fire. A critical factor in figuring out how much pressure to supply to a given fire hose (because it's the pressure at the nozzle that matters) is known as friction loss.. basically when you start flowing a bunch of anything through a hose the turbulence will create resistance. This phenomenon is highly dependent on hose diameter. The FL coefficient for a common 1-3/4" hand line is 15.5. For 2.5" it is 2. For 3", 0.8. For 5" supply line, 0.08.

As we learn about all of this one surprising truth is that a restriction in the line such as an appliance that necks down from 1-3/4" to 1", while definitely not ideal, isn't nearly as consequential as reducing the diameter of the 200' hose by even a quarter of an inch. All of this depending on volume and a bunch of other factors.

Obviously water is more viscous so this will be more pronounced with what we do, but it matters for air as well.

Bit off-topic but I believe this is part of why the 200-series implementation of KDSS can lead to the "head bobble" on certain terrain. Even though the bars aren't engaged, there is a limit to how quickly the fluid can flow from the front ram to the rear and vice versa.

This whole post is the very definition of a tangent.

So to compare your twin to the shop compressor, make the lines the same. Or, hook up a gauge at the end of the line right before the valve stem to see what pressure is actually being delivered to the schrader valve.

@bloc did you get an engineering sample or are these available to buy?

Any dimensional changes?

Not sure what you're referring to..

 

[OregonLC]

I was referring to this. Where did you find a brushless twin for sale? Didn't realize they were out yet.

I already have the brushed version on a slee bracket, and it’s awesome. All part of my strategy of keeping as much of the tools and “trail stuff” out of the cabin as possible.

 

[bloc]

I was referring to this. Where did you find a brushless twin for sale? Didn't realize they were out yet.

I wasn't clear, mine has brushes.

Edit: I'm on 3 hours of sleep.. probably making a lot more sense in my head than outside of it.

 

[OregonLC]

I wasn't clear, mine has brushes.

Edit: I'm on 3 hours of sleep.. probably making a lot more sense in my head than outside of it.

No, it was me. I miss-read your post.

 

[grinchy]

AFAIK, those valves still use the Schrader style and so inflation should not be so different. Deflation is way different because it bypasses the valve core. But if you took a look at the Monster valve, the valve core is much larger.

Yes, not the same but related. Morrflate says the standard Schrader flows ~ 2cfm at 20psi. while their compressor is rated at 7.1cfm @20psi. Old ARB twin is rated at 5cfm @20psi. My 24V Oasis compressor is rated at 16cfm @100psi!

Yeah, that explains why inflation isn’t much faster. Good catch! Deflation though, amazing.

 

[skrypj]

I really do not understand the Note on the site selling that inflator:

View attachment 3833117

Maybe I'm just having a senior moment, but how can running a compressor four times for a short duration shorten the duty cycle?

And the statement, "It just simply puts out too much air and is optimized for 4 tires at a time" makes no sense to me.

Enlightening comments?

TIA

I have a different version of this same dual piston compressor(Stop & Go from Amazon) and it filled all 4 of my 315/70R17 KO2's on my F150 from 9 PSI to 35 psi in 7 minutes exactly through a home made 4 tire inflator kit.

A single schrader valve would put a huge amount of pressure on the pistons in this compressor, and therefore a lot of stress on the motor. Even with the 4 tire inflator I was seeing 27 psi at the pump outlet when tires were at 9 psi. As the tires got closer to 35 psi I was still seeing 40 psi at the manifold on my 4 tire inflator.

So, I agree with the morrflate assesment, I would not use that pump to fill a single tire. I don't carry mine for daily use, I carry it when I know I am going offroad and have my 4 tire inflator with me.

The Morrflate is more sophisticated than the one I have. Mine was just an on/off switch with a 12V relay and some crappy filler hose. I added and ARB 100 psi pressure switch in series with the on/off switch, and drilled and tapped the manifold on the compressor for a Flexzilla High flow quick connect fitting. The high flow fitting was less for the compressor and more to increase how fast my 4 tire deflator could air down.

 

[TeCKis300]

I agree, the morrflate/EZflate is quite bulky. But you can get even more cabin space savings with a ARB twin under the hood. The new brushless version is 33-50% faster than the old version. It'll run just one of the two compressors in a low voltage situation or when in need of redundancy. If you want the digital pressure switch, you can add it. Cost is certainly much higher but it's better in many ways.

Wow, didn't know they came out with an updated unit. Thing is a beast!! Pulls 30A no load, but 90A at full tilt!

Since we're onto the topic of getting air out and in around the limitations of good ole' papa Schraeder

Apex RCV and RPV Fast Deflators

There's enough meat on this topic of Apex Deflators that it deserves its own thread. Screw on RCV (Rapid Connect Valve) Install / Replace valve stem RPV (Rapid Precision Valve) in std length (which should work with most OEM wheels) From the following discussion It's actually crazy timing...

forum.ih8mud.com

I can attest that airing up and down is faster with Apex valves. A lot lot faster to air down, and a bit faster to air up.

Loving my Apex RCVs. This is the ticket for large tires and I can air down all 4 tires in less than a couple minutes. Very satisfying.

I also see faster air ups which was unexpected. I don't see any marketing about using larger valve cores and curious why this is.

 

[skrypj]

I have a different version of this same dual piston compressor(Stop & Go from Amazon) and it filled all 4 of my 315/70R17 KO2's on my F150 from 9 PSI to 35 psi in 7 minutes exactly through a home made 4 tire inflator kit.

A single schrader valve would put a huge amount of pressure on the pistons in this compressor, and therefore a lot of stress on the motor. Even with the 4 tire inflator I was seeing 27 psi at the pump outlet when tires were at 9 psi. As the tires got closer to 35 psi I was still seeing 40 psi at the manifold on my 4 tire inflator.

So, I agree with the morrflate assesment, I would not use that pump to fill a single tire. I don't carry mine for daily use, I carry it when I know I am going offroad and have my 4 tire inflator with me.

The Morrflate is more sophisticated than the one I have. Mine was just an on/off switch with a 12V relay and some crappy filler hose. I added and ARB 100 psi pressure switch in series with the on/off switch, and drilled and tapped the manifold on the compressor for a Flexzilla High flow quick connect fitting. The high flow fitting was less for the compressor and more to increase how fast my 4 tire deflator could air down.

The other "issue" I had with my compressor was the voltage drop across the wires was like 0.5V which seemed kinda high for 6' of cable or whatever. I think some heavier cables could improve performance a bit, but not sure its neccesary as the pump is creating pressure against 4 schrader valves as it is. Until you get to 40 psi or so, the pump is moving so much volume that its creating a pretty decent delta P.

 

[hoser]

Loving my Apex RCVs. This is the ticket for large tires and I can air down all 4 tires in less than a couple minutes. Very satisfying.

I also see faster air ups which was unexpected. I don't see any marketing about using larger valve cores and curious why this is.

Looking a bit closer at the Apex valves.... I could only find a cutaway of the RCV (not RPV) but it looks like the housing around the Schrader valve is optimized versus the same valve core when inside a typical stem. Take a look at the 2nd pic, the tubing is barely larger than the core. So, I can see why you folks are getting better inflation times.

 

[TeCKis300]

Looking a bit closer at the Apex valves.... I could only find a cutaway of the RCV (not RPV) but it looks like the housing around the Schrader valve is optimized versus the same valve core when inside a typical stem. Take a look at the 2nd pic, the tubing is barely larger than the core. So, I can see why you folks are getting better inflation times.

View attachment 3833745
View attachment 3833746

Makes sense, and that RCVs and RPVs would share core design features. I was pleasantly surprised just how much faster as I was ready for longer air-up slogs with 37s, even with dual pumps.

Goes to show that while pump matters, it might be worth optimizing for better airflow across bottlenecks, whether with an octopus, valve cores, and possibly even air chucks.

Plug for a locking air chuck that I'm liking a lot. Easy one handed operation.

https://www.amazon.com/Locking-Chucks-Universal-Fitment-Connecting/dp/B0CWFM6ZJ3