What am I doing wrong?

[HarleyStBob]

Greetings from Texas Gentelman. I have a question on a recent air compresseor set up I installed. I have installed a Sears 80 gallon air compressor which is rated at 5 horsepower and will churn out a maximum of 175 psi in my garage with four air outlets. Each air outlet, I had planned, was going to have a specific purpose so I installed four Craftsman air regulators/filters, rated good up to 175 psi, on each air outlet. The problem is when I turn the air compressor on I can not control the pressure on the four air regulators/filters. The air regulators/filters make a hizzing sound and indicate pressures between 150 psi to 175 psi and no matter how many times I turn the knobs on the air regulators/filters the hizzing sound will not go away. I simply can not control the pressure on the four air outlets. What am I doing wrong, do I need a "master" air regulator on the compressesor to help me control the four air outlets? Suggestions are welcomed as I am fairly new at this. Thank you in advance.

 

[z28snksknr]

When you say the regulators show 150-175 psi, is that the pressure upstream or downstream of the regulator? If the system is not connected to a demand, all the regulators should read the same upstream pressure and be set to much lower pressures in order to regulate.

When the upstream regulator pressure is close to the setpoint, the regulator does not have enough differential pressure to seat the valving properly.

Lastly, stupid question - did you install the regualtors in the correct direction? It sounds possible that the downstream side (typically the side the regulator pressure reads) is on the supply side. If so, the regulators will bleed off the extra pressure to establish the setpoint. Since your supply pressure is static, that will never be achieved (continuous bleed-down)

 

[Major Ramifications]

Yeah, I was going to say to check the direction of the arrow on the regulators. Also, if you could give us a sketch or maybe some pictures of the layout, that would be helpful. Check the direction first, though.

Oh, I almost forgot, WELCOME!

 

[HarleyStBob]

When I said the pressure was between 150-175, I meant that all four regulators register the same pressure. I will look into the air flow direction. When you said "if the system is not connected to a demand" does that mean a master air regulator coming from the air compressor to reduce the pressure. By the way the Craftsman air regulator/filter is model number 916023.

 

[KenS]

The air regulators/filters make a hizzing sound and indicate pressures between 150 psi to 175 psi and no matter how many times I turn the knobs on the air regulators/filters the hizzing sound will not go away.

How long are you waiting to allow the hissing sound to stop? If your regulator is set to say, 90 pounds-- about normal for many airtools-- it takes a minute or more for the regulator to bleed off the excess pressure. If you are panicking at hearing the hissing air bleed-off and turning the regulator handle in and out without giving the regulator time to equalize, you will end up chasing your tail. The first time you hear a regulator bleeding off can be disconcerting if you're not expecting it. Same thing can happen with the compressor's unloader valve bleeds off after the compressor has reached pressure and cut out.

Also, as a test to simplify things, attach just one of your regulators directly to the supply outlet of your compressor-- inlet/outlet arrows on the regulator in the correct direction-- and see if you can regulate the pressure at the source. Remember, give the regulator a minute or more to equalize-- which means enduring the hissing. (In many home garage shops this is the standard setup-- a single regulator hanging directly off the compressor.)

One other thought: You didn't install the regulators in series-- the outlet of one regulator feeding the inlet of the next-- did you?

There is no need for a master regulator-- the pressure regulator on your compressor already does that.

BTW, 175 PSI output for a 5hp Sears compressor sounds a little high to me. Normally they are set at about 125 PSI from the factory, although the pressure switch may adjustable to a higher PSI.

 

[Jeepguy]

the point of use regulators to not need a master regulator off of the compressor to controll them. as for the hissing..... it sounds like you have them in backwards, when regulators are in backwards they will hiss out of the regulator cap because the air is trying to get out through the discharge where it is supposed to. regulators are designed to bleed down the pressure through the discharge when you use a tool. this is done after you set your desired pressure. just hook up a blow gun to the regulator and set it with that. but again make sure you have them connected the right way.

 

[caper]

Is your pressure gauge before or after the regulator?It should be after and with the line deadheaded you should be able to adjust the reg to show you your desired pressure.If it's before the reg it's going to show tank pressure no matter what the reg is set at.My vote is your regulators are installed backwards or are defective.

 

[Charles (in GA)]

Backwards regulators.

Charles

 

[HarleyStBob]

Thanks for all the info gentelman, your input really opened up my eyes. I went by Sears yesterday to look at the air regulators/filters since I did not want to take mine off from the copper set up that I designed. Anyways, I was looking for arrows to indicate the air flow and could not find them on the back of the regulators. After looking them over I realized that the arrows are stamped on top of the unit, hidden away by the bracket that holds them in place. To make a long story short, I do have them installed backwards. Again thanks for all the info and support. I will be posting before and after pics of my set up when I get done, in a day or two.

 

[z28snksknr]

Glad to help (and glad we were all thinking the same thing).

Looking forward to seeing your setup corrected and functional.

 

[Keep]

Most people would not have admitted they installed them wrong, they would quietly fix them and then blame it all on "bad Craftsman" quality.

 

[Major Ramifications]

Most people would not have admitted they installed them wrong, they would quietly fix them and then blame it all on "bad Craftsman" quality.

That's why I like this new guy, HarleyStBob, he isn't afraid to ask stupid questions, and admits it when he makes a mistake.

Most customers would have brought those regulators back to Sears, gotten some new ones, mis-installed those, then brought those back and would be ranting about what total **** Sears sells. In the mean time, Sears has eaten the cost of six regulators due to one customer's ignorance. Then the price goes up for all of us.

 

[Here2Learn]

Congratulations on getting the help you needed. I like this forum!

Please post some pictures when you can. Thanks!