RapidAir 1/2 or 3/4"?

[Automobilist]

Ready to buy for my new 24X50' shop. Puma 60 gal. compressor. General automotive use, not too heavy.

Any significant advantage to the 3/4" system?

Thanks...

 

[OldNeons]

We used the 1/2" kit in ours. If you run It in a loop you will get better airflow/volume. Unless you are running a big sandblaster or air hungry monster impact you should be fine with the 1/2".

 

[ADSR]

Bigger is better. go for the 3/4

 

[-->]

Id rather have it and not need it than need it and not have it. Go with the 3/4.

 

[sberry]

There is absolutely no reason to go to 3/4 and no reason for a loop. While the tubing I slightly smaller than a 1/2 pipe it still will deliver more than 2 of those comps would make with no noticeable loss. The smaller is so much nicer to fit and to modify, I use 1 size all I can with it being 1/2. So much easier to swap parts and modify manifolds.

 

[1Garageman]

I am subscribing to this question.

 

[happy]

I used the 3/4 and find that it is a great improvement over the hard pipe we had. The 3/4 also gives a little more storage in our case because the runs are fairly long. All in all I really like the product.

 

[squarles67]

I went with 3/4 in mine, it may be overkill but I'm ok with that

 

[Automobilist]

I get that bigger is often better. Does it make a material difference in my home shop though? The max run would be probably 65'. Cost is no big deal, but I think the 1/2" would be easier to install?

 

[squarles67]

The 3/4" was not difficult to run but I imagine the 1/2" would be easier.

 

[Jeff Ivers]

I, too, installed the 3/4 as I believed I needed the additional capacity. After installation, though, I realized all my quick connects were choking it down to 3/8 anyway, so did I gain anything? For others who went with 3/4, are you also choked down by your quick connects or is there a solution to that?

 

[squarles67]

All but one of my drops is indeed choked down by the quick connect.

 

[Nekit]

I'm running 1/2" PEX-AL-PEX. My T fittings do get kind of small .300" ID. I would imagine the RapidAir Maxline is similar. My longest run is about 70'. If you do the math is should provide plenty of air. I'm also installing it in a loop, so it is somewhat like a dual feed. One other consideration is that I am installing my air compressor (7.5hp, 80 gallon, dual stage, 23 CFM at 175psi)in a separate room that will have my blast cabinet, tire changer and outlet for outside sandblaster right next to it, on a separate leg (all of my heavy air users)

The reason I went with the 1/2" over 3/4" was cost, installation easy, and the fact that it was hard and costly to go from 3/4" T to 1/2" for the drops. 3/4" drops seemed like over kill to me.

In an ideal world I would have liked to run 3/4" main and 1/2" drops, but that wasn't going to be.

As stated be before if you aren't planning on using anything with heavy air usage (Sandblaster) 1/2 would probably be fine. If you are planning on installing a larger compressor and sandblasting or 3/4" impact, get the 3/4".

My 2cents

 

[LennyTheLizard]

I don't have a particular reason, but I bought 2 3/4" systems.
IF I recall, I found a good deal on the system on Ebay, and that was why I bought 3/4" - Buying the 2 100' systems was cheaper than buying 1 system with 300' of pipe + I got 6 drops.

In my 40X60' shop I have 1 drop on every wall + extra 2 on back wall where my workbench will be located. Pics near the end of my build thread.

 

[jgreen-fsi]

My 1/2 kit gets here tomorrow. I'm excited to get it installed. My thoughts were if I'm choking down to 3/8 or 1/4, why bother going with the 3/4 kit.

 

[bdog]

My 1/2 kit gets here tomorrow. I'm excited to get it installed. My thoughts were if I'm choking down to 3/8 or 1/4, why bother going with the 3/4 kit.

There is more to it than that. There are pressure losses over the length of run that can be quite substantial. Even if you are using a 3/8 coupler a 1/2 line could be the bottleneck if it is long enough.

As previously stated OP's compressor is not exactly huge so 1/2 should be able to keep up with whatever he is running assuming reasonable distances but you never really know what you might want to do in the future. For example I did my shop with 3/4" and upgraded my compressor twice. I am glad I didn't go with anything smaller. I also now use a 1" impact on occasion and have a special dedicated larger hose/coupling for it. Again I am glad the pipe is adequate.

 

[sberry]

I get that bigger is often better. Does it make a material difference in my home shop though? The max run would be probably 65'. Cost is no big deal, but I think the 1/2" would be easier to install?

This is the point.

Does it make a material difference in my home shop though?

This part should be repeated. The answer is no. In some cases I like a single run with a bit of velocity to push any water down to a drop, it wont go as well in a loop.

After installation, though, I realized all my quick connects were choking it down to 3/8 anyway, so did I gain anything? For others who went with 3/4, are you also choked down by your quick connects or is there a solution to that?

This is pretty much true and the real losses are at the end thru small hose and some at connectors but,,,,,,,,, this is not so much a problem as one may think and may help conserve some air on some tools. The idea isn't to whiz as much thru as you can but to get the needed work out of it. Bigger piping helps most noticeable with large impacts. Many a career mechanic has worked a long time with common automotive hoses and connectors, most do and only on the net is it much of a problem.

As previously stated OP's compressor is not exactly huge so 1/2 should be able to keep up with whatever he is running assuming reasonable distances but you never really know what you might want to do in the future. For example I did my shop with 3/4" and upgraded my compressor twice. I am glad I didn't go with anything smaller. I also now use a 1" impact on occasion and have a special dedicated larger hose/coupling for it. Again I am glad the pipe is adequate.

This is true and I go around a hose reel and use a 1/2 hose on the occasion I need a big impact. In my Buds auto shop they never used one in over 3 decades, never used a hose bigger than 3/8.
I would agree that in the right place a size up is worth it as are shorter hoses on secondary but we got most of the crowd that asks never gonna have 18 wheeler pull up in the yard to change out tires. I own 2 larger trucks etc and its very rare for me.
It may mean an alternative place to hook on for that occasion but every drop in a small shop doesn't need it.

 

[sberry]

My 1/2 kit gets here tomorrow. I'm excited to get it installed. My thoughts were if I'm choking down to 3/8 or 1/4, why bother going with the 3/4 kit.

This is true and these runs are usually pretty short. Many cases the figures are listed for losses at 100 ft but there is a chart for 60 which changes the math a lot and is more typical. If its adequate at 100 then its way above at shorter distances. Remember these formulas are usually quoting max load (the pex charts are some of the best as they have a load calc sheet to them which is simple to understand) but,,,,,,,,,,,,,, these losses are similar to 120V electric in terms of load and distance. Because we have a 12 wire and 20A breaker doesn't mean this is the typical load, there are some other reasons to have a bit bigger and its usually for motors etc and to avoid trips from them.
Reading the trunk and branch data and comparing to home run type systems is worth the time. 2 stage with regulation at point of use negates some advantages of larger mains especially in one user shops. Its one of the benefits of it, can use smaller primary piping. Its not as great a differential such as lp gas which often use a 3/8 primary and a larger 3/4 secondary but on short runs a 3/4 to a 1/2 drop doesn't offer much advantage and these systems are usually patterned for body shops with multiple users.

 

[Automobilist]

Bought the RapidAir M3800 kit, with 1/2" ID hose. Haven't seen anyone using this yet, so will report...

 

[Nekit]

Bought the RapidAir M3800 kit, with 1/2" ID hose. Haven't seen anyone using this yet, so will report...

What size is the ID of your fittings?

 

[sberry]

It is probably close to 3/8 nut its really minor in the grand scheme of things especially at hi pressure. Where I can see this stuff as really useful is to feed a remodel or addition and could be fast to get your feet underway. 50 ft of it will feed any common tool with un noticeable loss and the reg can always be turned up a couple #. One thing is not to add series of poor quick connects, a good system only has one at the hose. Decades of use by millions of mechanics been using old crappy fittings forever with whip hoses and 50 ft of 3/8 air hose. The loss down the main is rather insignificant.
The culprit is the 50 ft of 3/8, with a minor at the quick connector.
The upside is the hose is adequate and delivers it with convenience with only minor loss but if you want to gain the math for free keep the 1/2 main but put a 25 ft on the secondary to chop real loss in half given that the volume and gain would make this ******* in the wind effort worth it.

 

[sberry]

I say this with some objectivity and not soley viewed and skewed from my own perspective. I do have 3/4 pipe lines and large connectors because I am a class up from code standards on most utilities. I am a farmer mechanic and one circuit being 110 feet to the regulator and it does allow for a little cushion I spose. I never had a demand it wouldn't make. Same for another 40 ft circuit where I have used 3/4 impact.
The 1/2 hose whip to the gun was the major contributor to loss, all the rest of our work goes thru some 1/2 pipe to a couple 25 ft fixed whips and a couple 50 ft hose reels.
My demands are a gage higher but in general all the common fittings and hoses out supply the average user. I got a lot of tank and comp and finish my blast circuit off with 20 ft of 1/2 to a 25 1/2 hose and to tell the truth don't notice much if I change to 3/8, still can run it out of air if I try.

 

[sberry]

None of you are going to suffer much doing common auto body from undersized air. Sure you can scream it a little louder for a few seconds with some bigger hose but its a waste. I am curious though how much is 1/2. I have a couple I could re route and modify would be super easy.

 

[rburke65]

I think the average guy/al won't notice the difference between 1/2" and 3/4".

 

[600SL]

OK I did 3/4" iron pipe with a loop and it is defiantly overkill for a 1 man shop but it rally doesn't drive the cost much and I'm sure the same is true for the Rapid air systems. You will definitely have benefit in a shop my size with 4 guys doing body work but for me that is not the case.

What will really drive the cost of the system is every extra fitting and attachment you purchase beyond what comes with the kit.

Also as far as pressure drop, 1/2" pipe will do almost nothing compared to hose real pneumatic slip rings and QD's. These are the areas where you really need to pay attention. For my QDs on the ceiling that attach to my hose reals or pass air to my lifts I used 1/2 QD's which are available with a 3/8" thread to connect to your reals or lift drops. Best to not use a QD at all in these areas. Just plumb straight in but if you want ease of maintenance the large QD will suffice.

Another reason to use the 3/4" is that it is a stiff straight pipe rather than a flexible coil. You may just like the look of that but it will be significantly more difficult to install over the flex lines.

 

[600SL]

There is more to it than that. There are pressure losses over the length of run that can be quite substantial. Even if you are using a 3/8 coupler a 1/2 line could be the bottleneck if it is long enough.

As previously stated OP's compressor is not exactly huge so 1/2 should be able to keep up with whatever he is running assuming reasonable distances but you never really know what you might want to do in the future. For example I did my shop with 3/4" and upgraded my compressor twice. I am glad I didn't go with anything smaller. I also now use a 1" impact on occasion and have a special dedicated larger hose/coupling for it. Again I am glad the pipe is adequate.

If you use a 1" impact wrench then 3/4" system really is required. Those guns use about 75 CFM under full load. I would also advise a 3/4" system if you are using a 3/4" gun regularly.

 

[sberry]

I think the average guy/al won't notice the difference between 1/2" and 3/4".

Right. Its like hand washing at the kitchen sink, wont know what the difference is. You are not overloading a 1/2 with a 1/2 air gun but only about 80% tops.

Best to not use a QD at all in these areas. Just plumb straight in but if you want ease of maintenance the large QD will suffice.

I agree its worth some effort to avoid the connectors for a couple reasons. The small old style do restrict some but millions are used daily and its another place for a leak as well as added cost,,, plus in owner garages not a real deal but it keeps people from fooling with a connection they shouldn't.
I do use the barbs that come on the hose, 1/4 for 3/8. Messing with that on 50 ft of hose doesn't mean a pinch of **** and defeats part of the purpose of buying it ready made to screw it to it.
1000's of engineers and master plumbers use these fittings just fine till the internet came along. If one looks at the charts the real loss is down the hose but its why there is a reg set up to compensate, turn it up a little to overcome enough loss to make the tool run right, beyond that its irrelevant.
It is insignificant to the end user, only rarely is the loss or drop important.

 

[sberry]

I bought a comp and there was a Reelcraft with it. I was speculating and hoping it was 3/8 but it was 1/4 I was going to figure out if I had a place but we couldn't run a 1/2 air gun from it. This is the place the performance really tanks, look at the charts and compare a 1/4 and 3/8 at 15 cfm, really plummets even farther and faster at 20 and aint nuthin to write home about at 10 and the connector is irrelevant at those low volumes.
You get no argument from me that a guy running a 3/4 gun needs to install a 3/4 line especially across big tall shops.

 

[sberry]

I looked at some of the pricing on Northern for the flex. Its not bad especially if a guy kept it modest. It would be super easy for a couple runs I am considering changing but I think I back tracked to 1/2 black. Its quite a bit larger than a tubing. A 5/8 bit will go thru and a 13/16 will fly thru a 3/4.

 

[sberry]

One reason I am keenly aware of losses is irrigation. We do actually have a couple spots drop is a problem but only a couple instances does it really matter and I can shave the load. Not every section of the line is under duress, sometimes its to the first T and losses beyond don't add up to much. In air and potable water the loads are much different and as for air the pressures are a lot higher.

 

[dmeadow]

OK, this isn't easy to follow, so bear with me. There are two different products being discussed here: Rapidair and Rapidair Maxline. The 1/2" Rapidair is not constructed the same as the 3/4" Rapidair Maxline, nor is it measured the same. The Rapidair 1/2" is measured on OD, not ID. Therefore, the ID is 3/8", not 1/2". The Rapidair Maxline is 3/4" ID. So, you are really talking about 3/8" ID vs 3/4" ID. To confuse things further, there is a 1/2" ID Rapidair Maxline product, as well.

Further, the Rapidair product is nylon tubing and Rapidair Maxline is HPDE-Al-HPDE multilayer.

This is all explained on the Rapidair products website, but you have to do some digging and thinking to figure it out.

 

[Ilikeike]

I ran 3/4" copper down the center of the shop,then branched off to 1/2" ball valves and line where I needed drops,with the exception of the drop down for the blaster, which according to the manual required a 3/4" supply.

 

[Automobilist]

You got it sorta right...
The system I bought (M3800) has 100' of 1/2" ID P-AL-P tubing. same as the 3/4" but a touch smaller. It is not the poly tubing sold with the commonly advertised RapidAir 90500 kit. That kit's hose is 1/2" OD, 3/8" ID.

I don't know why they don't really advertise the 1/2" ID P-AL-P hose, as it seems like a great fit for home shops, etc.

I don't use any air tools larger than 1/2", we mostly work on our sports cars and vintage race cars.

OK, this isn't easy to follow, so bear with me. There are two different products being discussed here: Rapidair and Rapidair Maxline. The 1/2" Rapidair is not constructed the same as the 3/4" Rapidair Maxline, nor is it measured the same. The Rapidair 1/2" is measured on OD, not ID. Therefore, the ID is 3/8", not 1/2". The Rapidair Maxline is 3/4" ID. So, you are really talking about 3/8" ID vs 3/4" ID. To confuse things further, there is a 1/2" ID Rapidair Maxline product, as well.

Further, the Rapidair product is nylon tubing and Rapidair Maxline is HPDE-Al-HPDE multilayer.

This is all explained on the Rapidair products website, but you have to do some digging and thinking to figure it out.

 

[dmeadow]

I think if you read my post as carefully as I wrote it you won't find any "sorta" about it.

I, too, ended up buying the 1/2" ID HPDE-AL-HPDE Rapidair Maxline product to work on sports cars and a vintage race car.

I think they don't advertise it because it would confuse people as to why they sell two supposedly 1/2" kits at different prices.

You got it sorta right...
The system I bought (M3800) has 100' of 1/2" ID P-AL-P tubing. same as the 3/4" but a touch smaller. It is not the poly tubing sold with the commonly advertised RapidAir 90500 kit. That kit's hose is 1/2" OD, 3/8" ID.

I don't know why they don't really advertise the 1/2" ID P-AL-P hose, as it seems like a great fit for home shops, etc.

I don't use any air tools larger than 1/2", we mostly work on our sports cars and vintage race cars.

 

[Automobilist]

You are correct, and I hereby stand corrected...

Got my kit today, and will install it this weekend. What cars are in your collection?

Ted

I think if you read my post as carefully as I wrote it you won't find any "sorta" about it.

I, too, ended up buying the 1/2" ID HPDE-AL-HPDE Rapidair Maxline product to work on sports cars and a vintage race car.

I think they don't advertise it because it would confuse people as to why they sell two supposedly 1/2" kits at different prices.

 

[dmeadow]

You are correct, and I hereby stand corrected...

Got my kit today, and will install it this weekend. What cars are in your collection?

Ted

1951 MGTD
1962 MGA
1961 Jaguar E-Type
1974 MG Midget vintage race car

 

[gasgas17]

I was able to plumb both of my shops with 1 1/2" kit and some extra fittings. The garage is 24 x 22 and has 3 drops mostly used for air nailers and a blow gun. I also spray lacquer on occasion and use an impact in the drive way. The shop in the house has a drop on the bench for impact and a long run down a hall to the outside door for tire inflation in the drive way. Every air tool I own has a 1/4" quick connect and I use a lot of 1/4" hose too. As do most auto shops. Every thing works fine in my shops.

 

[ADSR]

After reading this, i'm going 1"

 

[Nekit]

You are correct, and I hereby stand corrected...

Got my kit today, and will install it this weekend. What cars are in your collection?

Ted

Out of curiosity what size are the ID of your 1/2" T hose fittings?
Thanks

 

[clubairth]

It's a good product and I used 3/4" RapidAir Maxline in my home shop of 30' X 40'. I have a 7.5HP compressor that can delivery 23.5 CFM at 175 psi and a very large home made blast box. Plus I like to paint using HVLP SATA guns. Both of these activities use HUGE quantities of air! This is my 3rd or 4th compressor so far and as always you just can't get too big of a compressor or too large of a blast box. Every time I upgrade I am amazed at what I can now do and wonder how I lived without it!

I found the kits are the best deal and Nothern Tool is where I got the kits. The small parts I got from TP Tools. The 100' 3/4" kit is on sale for $20 off. $159 instead of $179.

http://www.northerntool.com/shop/tools/product_200484023_200484023?utm_source=google_PPC&utm_medium=Dynamic+Search+Ads+Test&utm_campaign=DSA&utm_content=_cat:air%20compressors/kits&mkwid=sjwWcmSyR&pcrid=81459276911&mtype=b&devicetype=c&storeId=6970&langId=-1&type=search&gclid=CjwKEAjw8bO3BRDp0bP_vL-7_lASJACL_d6w2azDdNU33PhpfCBTYUdBzikW984XycJgdw6inOm0JRoCwdjw_wcB

These requirements steered me towards 3/4" piping and a full 360 degree loop system as recommended by RapidAir. Plus I am picky and wanted everything installed straight! So I wanted the Al. pipe. I built a pipe straightener that was posted on Garage journal. This really made a big difference and my piping looks very straight. I also spent a little more money and used elbows in several places I could have just bent the pipe.

Here is my setup on the pipe straightener. I probably will sell it since I am done but I ran almost 300' of pipe thru it! As others have posted the pipe comes tightly rolled up for shipping and it's tough to get it straightened out by hand so it looks half way professional.

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