Compressed Air Regulators - What Size?

[hughfree]

Guys - I am closing in on the completion of my new shop's compressed air system. I have installed type L copper (3/4" mains, 1/2" drops). I will be running a IR two stage, 5 HP, 80 gallon compressor. The system will be used primarily for automotive type air tools. My plan is to add a plasma cutter down the road. I may branch out and do a little painting as well. I am running tank pressure to the drops and will regulate at each termination. I have been doing research to determine what regulator size I should purchase. My initial thought was to maintain the 1/2" sizing but when I started to look around found that most of the local stores carry 3/8" as their largest sized regulator. What do the pros say?

 

[byoungblood]

It isn't hard finding 1/2" regulators if you look around. Northern Tool carries them in store. If you are limiting yourself to HD and Lowe's, then yes, 3/8" is probably all you will find.

Most good 3/8" regulators will flow 40+ cfm at 100 psi (so say the spec sheets), so a 1/2" is probably overkill for most. I have a 1/2" on my system, but I bought it cheap and run it right off the tank so I didn't want to have to adapt down to a 3/8" regulator in the first place.

 

[mechanic217]

Check Grainger for regulators, you should match them to the compressor CFMs, don't want to add any restriction.

 

[Kevin C]

When I replumbed the compressed air system at work I built a bypass using a Harbor Freight regulator. http://www.harborfreight.com/12-air-line-filter-regulator-with-gauge-68281.html

It has a couple of good reviews and a couple of bad reviews. Mine worked perfectly and supplied air to several large packaging machines without an excessive pressure drop. It was connected to a 7.5 hp IR compressor running about 50% duty cycle.

Name brand filter / regulators can also be found on E Bay, often times at a pretty big discount.

 

[930dreamer]

I picked up several from ebay, new in the box for a good price.

 

[sberry]

Menards has their house brand has an oiler you can toss but it is 1/2 and that makes it simple to pipe. 3/8 ported stuff is plenty and 1/4 is fine for some stuff and in some conditions. You will never know the difference in general auto work, never, the 3/4 mains are fine but overkill in a small garage too. 1 or 2 person auto shop this is moot, a strategicly placed hose reel and a drop or 2 is good, simple is good. I have added as needed but also went back and disconnect some I installed but never used. Got it so no hoses need to be plugged in for general work. All at the tool.

 

[TwoSmoke]

Glad I read this, I currently have a new to me camp/haus compressor that I am about to plum. The specs are: 7.5 hp, 80 gal, 17 cfm at 90 psi, 15.6 cfm at 175 psi. I don't do a ton of work with pneumatic tools but I was planning on running 1/2" hard lines then reduce to 3/8" regulators. The biggest thing I will most likely run is a plasma table at some point. Is my idea reasonable or should just pay the extra and get 1/2" regulators?

 

[Todd.Brock]

I have the same compressor specs as OP. I used 3/8 with no issues. Biggest issue with tank pressure at regulator is making sure the regulator is capable of 175 psi. I used an SMC regulator that wasn't the correct one and it quickly gave up in less than a year. I bought all new Milton reg; gauge and filter for about 100 bucks. It is rated for 175 psi on the inlet side. A lot of the HD/lowes stuff was only rated to 150. Just something to watch out for.

 

[hughfree]

Glad I read this, I currently have a new to me camp/haus compressor that I am about to plum. The specs are: 7.5 hp, 80 gal, 17 cfm at 90 psi, 15.6 cfm at 175 psi. I don't do a ton of work with pneumatic tools but I was planning on running 1/2" hard lines then reduce to 3/8" regulators. The biggest thing I will most likely run is a plasma table at some point. Is my idea reasonable or should just pay the extra and get 1/2" regulators?

TwoSmoke - I have a IR 5 hp, 80gal, two stage rated for 15.6 CFM at 175 lbs. I debated between a 1/2" Ingersoll Rand filter regulator and a Milton 3/8"filter regulator. The Milton was rated for more than double the air flow that my compressor would develop. I was ready to pull the trigger on this unit until I started comparing price. The IR unit was on sale for $64 and the Milton would cost $120 with a gage. I decided to purchase one IR unit and test it out. I need to buy a total of 4 and couldn't stand the thought of spending almost $500 for filter regulators! I would think that 3/8" would be perfect.

I have the same compressor specs as OP. I used 3/8 with no issues. Biggest issue with tank pressure at regulator is making sure the regulator is capable of 175 psi. I used an SMC regulator that wasn't the correct one and it quickly gave up in less than a year. I bought all new Milton reg; gauge and filter for about 100 bucks. It is rated for 175 psi on the inlet side. A lot of the HD/lowes stuff was only rated to 150. Just something to watch out for.

TB - That is one of my concerns....The IR is rated for 150 lbs at the inlet. I am going to split the difference and drop my compressor high limit to 160 lbs and test the IR. My decision is primarily a price and availability decision. Northern Tools had the IR's on sale and they had 4 units on the shelf.

 

[sberry]

Sometimes you have no choice to use several regs but I really try to get as much secondary on one as decently possible. I have 3 or 5 but 2 or 3 do most of the work covering 4K sq ft with multiple men. Some of these get changes, not scared to rework one or add fitting at any time,,, don't think this looks exactly the same today, a couple circuits since modified. There must be 5 circuits attached to this.