Air Compressor Line Confusion

[5window]

I'm sorry to bring this up again, probably. I have one of those smaller HF media blasters I want/need to modify to help along with my airflow-basically 10.5 cu ft/min at 90 psi. I was planning to use 1/2" black/galv iron pipe and fittings (increased over the 3/8" rubber and pipe on the unit). However, Grainger doesn't rate their black iron fittings for pressurized air.

Surely, iron pipe would handle this? Right? Thanks

 

[Git]

It may be an old 'wives tail' but I didn't think galvanized pipe was supposed to be used for natural gas or compressed air. Something about pieces of the coating could flake off and cause problems. I don't know if that is still the case, but it seems the aluminum pipe systems (rapid air, etc) would be the way to go, unless you have some specific reason not to use it?

 

[5window]

I'm talking maybe 2.5 feet of pipe, air flow to tank/ air flow to hose, shut off to nozzle and tank pressure relief valves/ a cross to relieve clogs at the bottom and a couple of reducers/bushing. Rapid Air may be too complicated for my needs. Mostly I am concerned about pressure-heard about the galvanized thing. Thanks.

 

[Git]

Personally, I used a 'whip' from the compressor to my 'hard' lines, and I used black iron after that

Like this - they come in different sizes

 

[GeoBruin]

I'm talking maybe 2.5 feet of pipe, air flow to tank/ air flow to hose, shut off to nozzle and tank pressure relief valves/ a cross to relieve clogs at the bottom and a couple of reducers/bushing. Rapid Air may be too complicated for my needs. Mostly I am concerned about pressure-heard about the galvanized thing. Thanks.

Grainger's website lists their black and galvanized pipe as schedule 40. The "max pressure" ratings they list seem crazy conservative compared to most specs I've seen for schedule 40 pipe but even the 150 psi @ 150 degrees should be serviceable for most any shop related compressed air needs.

Where are you seeing otherwise?

 

[u2slow]

What we don't use galvanized pipe for is fuel (diesel in our case). It usually finds a way to lift the coating.

Seems fine with low pressure air. Tougher to get good seals (especially unions) with 300-400psi. We're probably using sched 80 for that anyway.

 

[stonesfan68]

N/A

 

[stonesfan68]

It may be an old 'wives tail' but I didn't think galvanized pipe was supposed to be used for natural gas or compressed air. Something about pieces of the coating could flake off and cause problems. I don't know if that is still the case, but it seems the aluminum pipe systems (rapid air, etc) would be the way to go, unless you have some specific reason not to use it?

There are literally thousands of miles of galvanized compressed air pipe in use. There's nothing wrong with using it at all, there are just better options for some applications.

 

[Wrench97]

Black Iron pipe is best to use if you have a choice.
I usually use 3/4" pipe with 1/2" drops for 3/8 hose and 3/4 drops for 1/2" hose.
What size is the pipe fitting on the sand blaster?

 

[MarkH]

This is a discussion that comes up on a routine basis. So a partial summary of past threads. Compressed air is hot and contains moisture. It will rust iron pipes even those that are galvanized. Copper and synthetic pipes eliminate that problem. You do need to look at filtration for both water and particulates in the system. Regardless of system material, it is just more critical for some materials.

Also you need to understand the current and future use of the system. As stated the air is hot and contains water, if painting is in the future you need to be more careful in the pipe selection and filtration of the air along with making sure the piping is long enough to cool the air to the temperature you need. Each material cools air at a different rate. Never thought about that my first go around and that caused a replacement of the air system for painting and tools with less tolerances to particulates and water. All it was for was to move air for the impacts and tire filling around the shop.

 

[Lucid Moments]

Just use PVC.





/s

 

[nadogail]

Iron pipe, which is really Steel, has been successfully used for years.