Leak Free Systems w/ Bill Johnson

HVAC School - For Techs, By Techs

Bryan Orr

Training, Careers, Airconditioning, Self-improvement, Hvac, Business, Education, Refrigeration, Heating, Ac, Apprenticeship

4.8 • 985 Ratings

🗓️ 13 November 2017

⏱️ 48 minutes

🔗️ Recording | iTunes | RSS

🧾️ Download transcript

Summary

Bill Johnson is one of the great educators and writers of our time in HVAC/R. In this podcast episode, he shares some information about his career and some of his top tips on keeping systems leak-free.

Bill began his work on leak-free solutions by using Glyptal on centrifugal compressors. The Glyptal would harden around leaks and seal them up. Nowadays, this is an ineffective approach to sealing leaks in higher-pressure systems.

Bill got the idea to start manipulating pressures to minimize leaks with a standing pressure test for 24 hours at the highest test pressure recommended by the manufacturer. That is Bill's best practice, though it is not always feasible. Bill's rationale is that leaks become much more evident under those testing conditions. (Remember, pressurize the line set. Pressurizing the system can be a bad idea.)

On top of that, Bill recommends pulling a deep vacuum and performing a standing vacuum check according to the manufacturer's guidelines. Fitting inspections are also critical; fittings may be sealed imperfectly, and they are common leak points. Check fittings with a mirror and a good light to look for imperfections and cracks.

Leaks generally occur in piping, not the equipment itself. Moreover, vibrations and corrosion generally cause leaks.

Begin a leak inspection by leak-checking the gauge ports BEFORE attaching gauges. In general, inspect the entirety of the equipment with your senses before attaching gauges. When leak-testing with soap bubbles, make sure to use one that doesn't need to be washed with water, as water can lead to corrosion. (We recommend Refrigeration Technologies Big Blu.)

Most of all, don't leave a job until you find a leak or confirm that the system is leak-free!

Bill also discusses:

Being an HVAC teacher
Critical charge leak detection
Pressurizing with nitrogen
Misleading leak detection equipment
Torque wrenches

If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Transcript

Click on a timestamp to play from that location

0:00.0	Today's episode of the HVAC School podcast is made possible because of generous support from our sponsors,
0:13.0	Kesto, carrier, and rector seal.
0:17.0	And one thing that I want to mention to you,
0:18.5	today we're talking about leak-free systems,
0:20.3	systems that don't have leaks in them and one of the first steps to having a
0:25.2	leak-free system is getting a really accurate pressure reading when you do the
0:28.8	nitrogen pressurization. So we talk a lot about nitrogen pressurization today, but if you're using an analog gauge where even the width of the needle might have a resolution that gives you the idea that you're holding pressure when really say over a 20-30 minute standing pressure test which is
0:44.1	you know frankly what most of us do although we should probably do it longer than
0:47.3	that you may not see that change it may change just the width of that needle and
0:50.8	you may think that it's sitting where it needs to be.
0:53.2	And so by using advanced transducers, good quality transducers like they have in the Testo 550
0:59.8	and the Testo Smart probes, which are what we use at my business. You can really see at a much
1:04.4	more detailed, a more granular level if you will, the changes in pressure and that gives you
1:09.6	a better idea whether or not you have a system that's dropping and it gives you that idea quicker.
1:13.0	Now keep in mind, you have to pay attention to ambient conditions, changes in temperature.
1:16.5	We talk about that a little bit in this episode, but using a very accurate set of gauges or an accurate smart probe is going to give you a much better sense of if you have a
1:26.0	system that is leaking or not. So thank you to Testo for sponsoring the
1:29.8	podcast and if you don't already have a good quality set of high-end digital gauges if you are a
1:36.3	technician who's out there in the field doing it and you want that additional degree of
1:40.2	accuracy then check out the testo 550s and the Testo Smart Probes. This is the man who had posters of Willis Carrier and John Gory on his wall as a teenager.
1:57.0	Brian Orr.
1:59.0	All right, all right, all right.
	...

Please login to see the full transcript.

Previous episode | Next episode

Disclaimer: The podcast and artwork embedded on this page are from Bryan Orr, and are the property of its owner and not affiliated with or endorsed by Tapesearch.

Generated transcripts are the property of Bryan Orr and are distributed freely under the Fair Use doctrine. Transcripts generated by Tapesearch are not guaranteed to be accurate.