Reddit mentions: The best industrial pressure gauges

Without tools, the best you can really do is look for oiliness on the pipe. When you find a joint that feels oily (look for dark colours on the pipe, usually covered in very fine dust. Once you rub the dusty area with your fingers you'll feel the oiliness), spray/pour a small amount of washing up liquid over it and look for bubbles. If there's any refrigerant left in the system, you'll usually see bubbles appear (or over a longer period, foam). Of course if the gas has all escaped already - and we're only talking a couple of hundred grams here - then you won't see any bubbles.

Most domestic gear has no access fitting at all so even locating the leak can be difficult if there's no visual indication. You need to get pressure in there so you can leak test - this means adding a bullet piercing valve (like this).

Then you need to put something in via your bullet piercing valve to raise the system pressure. It's best to use dry nitrogen to leak test to save wasting refrigerant, but since you most likely don't have that on hand you could buy yourself some refrigerant (most likely R134a) and pressurise with that. That's a big no-no here (both disposable cylinders and dumping gas to atmosphere by charging a system with a known leak) but I'm guessing your in the US, and those sorts of laws seem remarkably lax so go for gold. It's not like you'll be ruining MY ozone layer too, right? ;)

You also need to regulate the pressure going in to the system. This is where you need gauges. Connect the yellow line to your bottle, connect the blue line loosely to your bullet piercing valve, purge from cylinder to piercing valve by opening the cylinder tap + gauges tap, and releasing some pressure via the loose fitting, then tighten the fitting and close your gauges tap. Open the bullet piercing valve. Open the gauges tap slowly and give it ~50psi of system pressure.

Then you can go for gold with your soap, or you can lash out and grab yourself some "proper" leak detection fluid (like this), or better yet an electronic leak detector (like this one).

Once you've found your leak, you want to release your nitrogen (or reclaim your refrigerant using a reclaim plant and a spare cylinder), then repair it using an oxy/acetalyne set, or since it's only tiny pipework you can get away with a MAPP gas set.

If it's a copper->copper joint, you're laughing - polish the pipework up with emery cloth, heat the pipe until it's just this side of glowing red, and feed the joint with brown tip silver solder.

If it's a copper->steel joint, then it's a bit more of a pain. You need blue tip silver solder and flux. Clean your joint with the emery cloth, give it a nice coating of flux on every surface you need solder to stick to, then heat it up until it's a fair way short of glowing red. Feed the blue tip solder in and STOP. Unlike brown tip (15% silver) you can't just keep feeding blue tip (45% silver) as it ruins the weld.

Now, since you put on a bullet piercing valve and they leak like a sieve in the long term, we need to replace that with a schrader access valve. Since it's most likely going to be in a straight through piece of pipe, you can save time and grab yourself a pre made access valve in 1/4" pipe. Cut away the hole left by the bullet piercing valve, polish the copper and cut the pipework with a ~10mm gap using a tube cutter. Then slip your access fitting assembly in there, and follow the copper->copper joint procedure.

Of course, now that we've done all that you need to change the liquid line filter drier too. I'd recommend a 1/4" solder in core drier in place of the original copper spun drier because... well, copper spun driers are terrible. Follow the pipe cutting procedure from the piercing valve instructions and the soldering instructions from the copper->copper joint instructions and that's done too. Remember - always try and mount the drier so it's outlet is LOWER than its inlet. This turns the drier into a small liquid receiver and helps ensure a good liquid seal over the capillary tube. Speaking of capillary tubes, if it was inserted straight into the original copper spun drier CUT the capillary, don't try and unsweat it. The chances of blocking it up are about 82.5634% (approximately) when you unsweat capillarys. You're much better off chopping it with a set of capillary tube cutters and ensuring a good clean capillary. The ~30mm of wasted capillary will affect performance, but almost certainly not to any sort of measurable degree.

Then give the system a good evacuation using a vacuum pump and ensure it reaches a good vacuum (sub-500 micron) with a digital vacuum gauge.

Then using a set of electronic scales, charge your freshly evacuated system (remembering to purge!) to the charge recommended by the manufacturer.

Voila! You have just fixed your chest freezer.

..... Alternatively, pay someone to do it for you and/or recycle the components and buy yourself a new one.

I'm serious about the rear tire pressure. It's probably around 35-40lbs of pressure right now. Get a really good tire pressure gauge... because you need one anyway. I could build a nice house for what you have invested in that bike, so don't be cheap and get a good one. Hell, even if you don't change the tire pressure like I'm suggesting, you still need a good tire pressure gauge.

There's a ton of $10 gauges floating around, but I've never found two that read the same, so all of them can be counted on to be inaccurate. But there are good, relatively inexpensive gauges out there. Avoid the digital ones unless you into the >$200 product lines. Not necessary unless you work on a racing team and 1/10lb differences are going to be appropriate and necessary for track condition changes. But GOOD dial-gauges with flexible hoses can be had for about $40-50. Intercomp and Joe's Racing both make reliable, accurate gauges, and they're almost as good as the ones for professional racing teams. Make sure these are 60lb gauges, because you can use them on your car and truck, too. Buy a good one once and you'll never need to buy another. I know you understand this idea.

You probably don't have an inner tube in that rear tire so don't go below 20lbs ever, although I've limped my Road King home on a tire going flat that had about 15lbs in it (an 800lb bike is NOT the same as the 475lb bikes that Harley recommended 15lbs of pressure for). but 22-25lbs is more than enough for the tire to retain its bead on the rim under almost all conditions (except drag racing, unless you're rolling on the throttle instead of dumping the clutch) and hitting a hard curb straight on at 50+mph, and then you'e already got other problems. But running 22-25lbs may make the difference between enjoying every minute of your ride and having to buy a football mouth guard to keep from breaking teeth. OK, you probably don't need the mouth guard, but the difference between 35-40lbs and 22-25lbs will be night and day. Give it a try?

This is good info. I did a bunch of pex work and I pressure test my stuff now with a bike pump, a test plug, and a spray bottle of soapy water. I got the little pressure test thing from ACE, (Only mine goes to 60 psi)

http://www.amazon.com/Jones-Stephens-G64-015-0-15-Pound-Gauge/dp/B000HEC3YK

I have copper in my little house, but I HATE the way the person plumbed it. The water has to flow, even in a 1/2 pipe, to the bathroom sink for about 30 feet when the HWH is only about 6 feet away.

It's like they didn't sit back and go "sigh" this will take longer but it's better overall. They went "sigh" this will cost the previous homeowner 100 bucks more in copper pipe to just follow the old path that previous remodel locations which had organically grown had taken. Let's also put a pipe in front of a hatchway! Hooray!

The 64 dollar question is how do you make the pex that is all rolled up straight again without the expensive unwinder... I've tried a heat gun and VERY CAREFULLY with a torch and nothing really makes it flat straight. Nothing short of quick nail it to the stud and forget about it.

That is normal...some do it more than others, definitely get yourself a new gauge though. Installation is very easy. www.amazon.com/Oil-Filled-Vacuum-Gauge-Lower/dp/B006VCGSP2/ If someone else with proper knowledge cares to chime in, not sure if fresh oil will create less exhaust?

I use this one paired with this gauge and this connector, and love it.

I'm glad to see more people are mentioning this, it's (IMO) a much better way to leak test without the risk of actual leaks. Some Amazon links for my current setup:

You'll need a pressure gauge, https://www.amazon.com/dp/B0087UCI8C/ has a relatively low maximum for high sensitivity (easy to see if there's a drop)

You'll need a valve you can hook a hand pump on to (like what you'd use to pump up a bike tire -- I don't recommend an electric pump because of the low pressure you need). https://www.amazon.com/dp/B001PLI4BA/ is in the same threading as the gauge.

You'll need a tee to connect these things to -- https://www.amazon.com/dp/B000BQUTBS/

Finally, connecting the tee to your rig. I take a scrap of tubing, put a fitting on one end, and slip the other over: https://www.amazon.com/dp/B000CFNKBO/ (check for your tube's inside diameter!).

Assembly is pretty straightforward, wrap some pipe tape around each component's threads and screw into the tee. Before connecting to your rig, you may want to cap the open end and pressurize it a bit to make sure you're not starting with any leaks. Connect in to your fill or drain port as appropriate, and slowly pressurize the system. You don't need a ton, only 8-10 psi is plenty, and is more than the water will be operating at. Mark the gauge position, and come back in a few hours. If the needle has moved, you've got a leak -- you can swab glycerin or dawn soap around your seals to find where. If not, you know that air at higher than normal operating pressure isn't leaking out, and that's a nice tolerance to know you have!

That gave me a great idea! What if I bought all 5 of these items and rigged them up in order onto a 12 oz soda bottle:

• PET Bottle "Carbonator" Cap
  
  
• Disconnect with 1/4" flared male
  
  
• 1/4" flared female to 1/4" MPT
  
  
• 1/4" FPT coupling
  
  
• 1/4 MPT Digital Pressure Gauge

Looking at a pic that gage might be replaceable. A back mount gage like this might work.

www.amazon.com/dp/B016MM67TM/ref=cm_sw_r_cp_api_Gs7ZxbA4M1GJ3

You don't need to buy those pre-made ones. You can just make one yourself with cheapo non-watercooling components. Low-pressure air gauge, a schrader valve, a t-block with one male and two female ends, and a thread adapter. About $20 worth of stuff, assuming you already have something to pump it with.

I made a fixture that screwed the cap lid down. It makes zero difference in the leaks.

I've purchased a nice vacuum gauge, https://www.amazon.com/gp/product/B002JP5PAE which allowed me to eliminate the arduino with BMP183 inside the chamber. I still see the same level of leak, so I feel comfortable that outgassing by the arduino or its battery isn't the cause of the slow increase in pressure.

I noticed that the hose fittings (1/4" flare) are prone to leaking. At this point, it seems like my (pipe-thread and flare) fittings connected to the vacuum chamber are the remaining source of leaks- either they aren't tightened enough, or they have leftover oxygen in the threads.

I haven't completely eliminated outgassing of acrylic as the othe rremaining cause of pressure increase. I guess the only thing I can do is continuously pump the chamber for a couple days without exposing it to atmosphere.

So I got the spout to come off, now for the next part.

Do you think

https://www.amazon.com/dp/B008VO5RHI/ref=twister_B00GGDY6CS?_encoding=UTF8&psc=1
and
https://www.amazon.com/dp/B001PNIL48/ref=twister_B007D995UC?_encoding=UTF8&psc=1

would work also?