I may need to install a loop for an RO in a hospital room.What is the easiest way to pressure test the loop for leaks once I am done?

I would like to test the loop before the RO is put in. Thankfully everything will be surface mounted so it will be easy to spot leaks.

I think I can do this--outside vendors will charge us a fortune and the hospital wont do it.

I'll take any tips you may have.

If you have access to a small air compressor you can do this easily. You are going to have to close off all the access points and loop return(s). Connect the air line from the compressor to a point in the loop that has a shutoff and a pressure gauge on the loop. Pump up the loop to about 5PSI, and close the shutoff to close the entire loop. You can then wait and see if you have any drop in pressure, and if you do, start checking joints with a spray bottle full of soapy water. A leak will be evident quickly.

Yes I agree with traveler but I would pump up the pressure and try to keep a static pressure somewhere around 40 to 60 psi wich should be around your normal operating pressures then watch your gauges

Bioman,

Remember that air pressure is very different than water pressure. If you try to pump up the entire loop to 60PSI of air, you are asking for trouble. First you would have a hard time getting the pressure that high, and at that pressure if you had a failure, someone could get hurt by the ensuing shrapnel. Imagine standing in front of an exploding tire at 60PSI. 5PSI is what most plumbers use to pressure test.

Testing at 5 psi tells you almost nothing. An unglued, hand tight PVC fitting could hold at 5 psi. At our construction projects the plumber air tests at considerably higher than 5 psi. After the plumber is finished and the water treatment system has been installed, we test the loop with water at 100 psi for five minutes, and we have found leaks that way even after the successful air test. While I guess it is possible in theory for the pipe fail and "explode" it is highly improbable.

Pressure is pressure, water or air, no difference. It will take a very large volume of air to pressure test a very large loop, but the pressure arrived at is the very same force; water, air, nitrogen whatever. Most PVC pipe is rated well above 100 psi.....I think. I recall the standard at maybe 1/2 the rated max so 60 to 70 psi, maybe. Local code should stipulate, may vary from area to area. (?) More importantly, when selecting a source of AIR for the test, it should be a medical grade source, or VERY clean. NOT an ordinary compressor etc. These devices are deliberately lubricated - don't want nasty lube in the loop!!! Once you put aerosolized lube in the loop you will never get it out.

Dean

quote:

Originally posted by Dean Peterson:
Pressure is pressure, water or air, no difference.

Dean

This is absolutely incorrect! Air and other gasses will compress under pressure, water will not.
Traveler is right in saying air pressure tests should be done at lower rates (usually 5-10 psi)

quote:

Originally posted by Dean Peterson:
Pressure is pressure, water or air, no difference.

Dean

Your wrong! Air and other gases compress under pressure, water does not. Hence the name air compressor.
So 60psi of air is more volatile than 60psi of water.
Traveler is right. Air testing a confined space such as a water loop, should be done at low pressures(no more than 5-10 psi)
Anything higher, no matter how improbable of an explosion, is unsafe.

SDCT, while you are correct in saying water will not compress under pressure, 60 psi is 60 psi, no matter what the medium. It could be water, air, or any other fluid (yes, air is a fluid). Dean Patterson is 100% correct.

Wow didnt mean to start a whole argument over this! Our plumber tests at 5-10 PSI with compressed air. That's where I got the information from.

You have to think of the force required to compress. Air is much less dense than water. Therefore, it requires much more force to compress. Now you have to think of the expansion that will occur under failure. The water will not expand much, while the air will expand violently. Therefore, there is a difference between air and water pressure. I do agree that 60PSI of air and 60PSI of water exert the same force on the pipe. If anyone is using compressed air to 60PSI in a PVC system, you're asking to be a Darwin Award recipient.

OSHA on PVC Carrying Compressed Air

Read that link for some cases where unfortunate incidents happened when someone tried to use PVC to carry compressed air.

Frank,

I agree with you and Mark and Dean that 60psi is 60psi no matter what the medium. What I was trying to get across is...That statement, in the context of this discussion, is misleading. While the psi may be the same, no matter what the medium, you have to look at how the medium will discharge said pressure.
Telling someone that if you charge a pvc line with "x" psi of air is the same as charging it with "x" psi of water is what is wrong. (not in the technically sense but in the realistic sense)
Would you like to be staring at a plug on a pvc pipe with 60psi of air behind it or 60psi of water.

The point I am most anxious to make is not to use an ordinary compressor for the test. Ordinary compressors rely upon lubrication, typically. The aerosolized oil will ruin the loop. Thats all.

Dean, you can use a regular compressor as long as you have a moisture trap and a filter on the output of the compressor. It is a similar setup that you would use on a compressor for running a paint gun.

While it is enormously convenient and tempting to use an ordinary compressor, it would not be a good idea to use an ordinary compressor with or without the typical water trap or filter. Some oil from the compressor can/will still get into the loop. Why contaminate a brand new loop with oil? It will be tough enough to keep it clean w/o oil. You could use medical gas instead, it is usually a higher quality, filtered product. Don't think I would suggest Oxygen, but med grade air (or SCUBA), or nitrogen would be very good. Use a regulator between the source and the loop to drop the pressure to the appropriate range, whatever that may be. Or, use water as previously suggested.

Might be easier to just pressurize the loop with the water your going to be using. leaks will be seen very easily. just watch closely. good luck.