Air connector question

[rjprice]

Beginning to pipe my 40x50 shop for air. Using copper, 3/4 with 1/2 drops. I decided to use I/M 3/8 x 1/4 npt connectors. The "hole" is even bigger than the Milton V and I had them on hand. The question is what size copper fitting should I use at the end of the drops? I could use 1/2 x 3/8 npt or 1/2 x 1/4 npt both sweat. I can get the coupler for these fittings in either 1/4 or 3/8 npt at the same price.

I'm going to put 2 hose reels in the shop and plan to use hose with 3/8 copper ends and these I/M couplers. Ideas?

 

[sberry]

Why put 2 steps in when 1 will do? In fact why mess with 2 sizes of pipe? Run 3/4 all the way.

 

[sberry]

I use M,started with it, can use it on heavier tools too.

 

[bad_idea]

I would use the 1/2 x 3/8 NPT on the end of the drops. That will give you flexibility in the future. Why neck down to 1/4 NPT when you can get 3/8 NPT for the same price? The 3/8 NPT may prove handy for a larger stationary piece of equipment in the future, or for a tee to feed two items.

It is good to pipe the 3/4" pipe along the ceiling in a loop around the building with the 1/2" drops coming out of the top of the 3/4". It takes 2 90s and 2 45s to drop down the wall, but the water will be trapped in the 3/4" and never make it into the 1/2" drops. You will then need a drop out of the bottom of the 3/4" with a ball valve on it to catch and drain any water that makes it into the 3/4. You want the 3/4 to loop all the way around the building to allow the air to flow both ways to feed any loads. For a home shop with a single user this is likely overkill, but there is no kill like overkill right?

 

[like2wheel]

I would use the 1/2 x 3/8 NPT on the end of the drops. That will give you flexibility in the future. Why neck down to 1/4 NPT when you can get 3/8 NPT for the same price? The 3/8 NPT may prove handy for a larger stationary piece of equipment in the future, or for a tee to feed two items.

It is good to pipe the 3/4" pipe along the ceiling in a loop around the building with the 1/2" drops coming out of the top of the 3/4". It takes 2 90s and 2 45s to drop down the wall, but the water will be trapped in the 3/4" and never make it into the 1/2" drops. You will then need a drop out of the bottom of the 3/4" with a ball valve on it to catch and drain any water that makes it into the 3/4. You want the 3/4 to loop all the way around the building to allow the air to flow both ways to feed any loads. For a home shop with a single user this is likely overkill, but there is no kill like overkill right?

Yes, this is the best way to do it, & I agree that a complete loop might be overkill. But either way the 3/4 should be pitched slightly to the drop for drain. Unlike the air drops, this tee should point down.

I also agree with his point about 3/8 giving more flexibility