Service Valve Tips - Short 105
HVAC School - For Techs, By Techs
Bryan Orr
4.9 • 1K Ratings
🗓️ 29 December 2020
⏱️ 7 minutes
🧾️ Download transcript
Summary
In this short podcast episode, Bryan talks about some tips you can use when working with a multi-position service valve.
A service valve will have a line connection, which connects the valve to your line set. You also have a gauge port that you can connect to, a valve stem, and a packing gland nut (directly beneath the valve stem).
If your stem is completely back-seated, then your gauge port is completely closed from both the line and system connection. If you crack the stem off the back seat, then the gauge, line, and system can all communicate. Completely front-seating the valve will generally close off the line connection, but it may also close off to the system connection on some valves. Mid-seating puts the valve stem right in the center for maximum flow.
If you're working with a service valve in a grocery refrigeration application or old A/C system, you may be tempted to use any old wrench on the valve and can damage the valve. So, whenever you work with one of these valves, make sure you use a refrigeration service wrench only. Also, be sure to exercise caution.
The packing gland nut helps keep everything together and prevents leaks. However, you need to loosen it by a quarter to full turn before opening the valve. If you don't loosen the packing gland nut, you will have a hard time adjusting the valve, and you may even damage it.
Whenever you do any brazing on or near a service valve, be sure to protect it from the heat (such as with Refrigeration Technologies WetRag). You'll also want to mid-seat the valve before you start flowing nitrogen.
Learn more about Refrigeration Technologies HERE.
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Transcript
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| 0:00.0 | Hey, this is Brian with the HVAC school podcast. I'm actually sitting on on my porch. |
| 0:08.0 | And I thought, you know, let me grab my mobile mic and let's talk about service valves. But before we get to that, let's thank our sponsors. |
| 0:16.5 | And our sponsors are carrier and carrier.com, navac and navac global.com. |
| 0:21.5 | Refrigeration Technologies at Refrigged Global.com. Refrigeration Technologies at refrigitech.com. |
| 0:25.0 | They make Viper and Venom Packs and Nylog and all kinds of great chemicals that are |
| 0:30.0 | well thought out and that work great for technicians in the field. |
| 0:33.3 | Find out more by going to a FridgeTech.com. |
| 0:35.7 | Mitsubishi Electric. |
| 0:37.1 | We have been Mitsubishi Diamond Dealers, Diamond Contractors |
| 0:41.3 | for years and years at Kailos, and Mitsubishi is coming out with more and |
| 0:44.4 | more innovative products to serve both commercial and residential as well as |
| 0:49.5 | high efficiency, high performance homes. If you haven't looked at Mitsubishi in a while now is the time to do so. |
| 0:55.9 | Find out more at Mitsubishi comfort.com. |
| 0:59.8 | All right so service valves and when I talk about service valves, I mean, there's the adjustable |
| 1:06.1 | service valves, the multi-position service valves where you can actually open and close them, |
| 1:10.8 | front seat, back seat, neutral seat, that sort of thing. |
| 1:13.0 | And that's mostly what I'm talking about here, but some of this also applies to kind of your |
| 1:16.1 | traditional service valves that we see on residential systems as well. |
| 1:20.5 | A little bit different design. |
| 1:21.8 | But there's a couple different key components to a service valve |
| 1:24.5 | you have the line connection so the part that actually connects out on a typical |
| 1:30.2 | residential system that would be out to your line set. But say if it was a |
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