Nathan K5LA line upgrade

Hey fellas. As of now Im running 3/8" id line (its actuallyhydrualic line lol) and was wanting to upgrade to 1/2" id DOT line. Im running a 1/2" valve at the tank and running my line from it to the horns. (Reducers in the valve to accomidatethe 3/8for now lol). My question is will it make a big diffrence? I have my line going into my horns on the side ( i think its 1/2" port) as i cannont go in through the top due to mounting situations. Also is there a need to run a regulator? Will 150 psi ruin my expensive horns

Most guys will use 120 to 150 psi all day long, but be more concerned about volume. You need to supply those horns with about 90 CFM to make them sound nice at 120 psi.

If you have a manual valve, you can run pressures a bit higher since you have more control over the air.


I run a 1/2" parker 12volt valve and i have a 120 psi cutoff switch but bypassed itand fill up to 150 psi just seemed louder but i dont wanna damage my 1500 dollar horns lol. Will going feom 3/8 line to 1/2 make a big diffrence? Im also running a 5 gal tank and a 444c compressor that has 100% duty cycle

Going from 3/8" to 1/2" gives you more storage but to increase flow rate every fitting and port also needs to be 1/2".

I have 2 1/2" fittings ready to go… will goin from 3/8 to 1/2 make a diffrence

Well im at a stand still the only line i could get was 1/2" rubber line. So the only idea i have is to use barb fittings and the only one i can find is 3/8 barb id. So now what do i do

I went to the local “Home Depot” and got all my 1/2 inch fittings for mine. Might check online? note, I had to get my 1/2 inch GoodYear Air line from ebay. lol.

As long as the inside diameter of your rubber line is 1/2 inch and it’s rated for the pressure you intend to use, it will be fine. I use that myself. You might even want to go 5/8ths inch ID since you have a K5, which uses a lot of air.

My line is 1/2" id rubber hose but i can only run a barb fitting (so i was told) with this line. So it accepts the 1/2 but the id of the fitting is 3/8. I found a barb fitting that is 3/4 that the id is 1/2 on can i maybe stretch the rubber line onto the 3/4?

As long as the restriction is just in a few places, you will still get decent flow. Where you have issues is when the entire pipe or hose is a smaller diameter. And if you measure the pressure at the horns, you can raise the pressure at the tank to compensate for losses in the piping system until you get to the pressure you want.

My valve is directly on the tank so the only restriction i will have is the fitting after the valve and the one entering the horn.

Use a larger valve, so the fitting won’t be the restriction.

When I did the 3/8 swap to a 3/4 valve I was blown away. I use a 5/8 id hose now and a 3/4 ball valve super loud. About twice as loud as the 3/8’s airline.

I also used 5/8" ID hose and barbs. I blew the hose from Home Depot and had to replace with 300psi WP hose.

Wow does yours hold air the whole time? Mine wont itll just be when i blast it

I got it all finally done. I can say it seems about the same db level but sounds more like a train. All my fittings are 1/2" except one so well see how it sounds when i get it fixed up

Yup, and you’ll get that because there is more volume getting to your horns :slight_smile:

It’s a huge difference, and you’ll even get a good echo too!


Not sure what you mean. I always left air in the system. With that setup I had leak-o-rama, but it wasn’t because of the hose. I used 2 worm drive hose clamps per barb.

I was wondering if that lime had complete pressure on it.

Yes, it was holding 200psi between the tank and the valve.
It was some cheaper hose from Home Depot.