Installing two TCL 36k heat pump mini splits in my central OK 40x50x14 red iron shop. R454B units, need to pull vacuum, need adapter...

[1320stang]

I have a yellow jacket gauge set for R12/R22/R502 and a HF Pittsburgh set for R134A/R407C/R404A. I have an OLD Robinair model 15021 belt driven vacuum pump with an adapter that allows me to hook up my HF set to it. I just need to adapter from a blue hose to the vacuum port on the unit. Most I see are for a tank connection (left hand thread). The vacuum port is right hand thread and has a shreader valve in it.

I know R454B is flammable but the condenser comes charged and the linesets are atmosphere. The pump wouldn't be running when the condenser connection valves are opened.

I've googled it but am not sure if the Amazon ones it points me to are corrects, typically it points me to a pair and I only need one.

 

[manwithtools]

For the cost of those two units, just buy a modern vacuum pump and needed fittings. You will still save way more than a installer would charge. They are cheap enough on Amazon or Vevor to not be worth the hassle with your old equipment.

 

[1320stang]

They were $2250/ea. I doubt I do any home hvac work. My son-in-law bought a set of R1234yf gauges, I wonder if they're compatible. I hate to spend a couple hundred on something I'll use once (or twice, for each unit).

 

[462867aa]

if i remember right, my unit took a 5/16 adapter. Cheap an amazon. Take a look!

 

[todd_fuller]

I have an R32 unit which is an A2L and the unit itself has normal ( for a minisplit) fittings. It’s the refrigerant tanks and recovery tanks that have reverse threads.

Why do you need a gauge set? You probably only need a valve core removal tool for mini splits. I vacuumed my lineset with only this and a micron gauge.

Make sure you put new oil in the vacuum though, you’ll struggle to get below 500microns otherwise.

 

[fitter30]

3Pc R32 R454B Reverse Thread Brass Adapter, 1/4 Inch Female to Male Fitting for Refrigerant Tank Vacuum Pump and Gauge Hose - Walmart.com

Buy 3Pc R32 R454B Reverse Thread Brass Adapter, 1/4 Inch Female to Male Fitting for Refrigerant Tank Vacuum Pump and Gauge Hose at Walmart.com

www.walmart.com

 

[1320stang]

Problem with those is the reverse thread. Every hose I have is RH thread as well as the vacuum pump connections and the vacuum port connections on the condensing unit. I'm hoping they used a 410A valveset. Looking at another post where a guy put in Pioneer a mini split, I ordered a pair (only need one) of fittings off Amazon for $8 that are 1/4" RH male and 5/16 RH female 45's that look like what he used and his valveset looks exactly like mine, heck the unit looks the same.

Supposed to be here today. Jeez it was 108*F or 109*F yesterday, weatherman said it would be up to 10 degrees cooler for a couple days, whoopie....

 

[gagecalman]

You spent a good bit of money for the units so take the time to do it right.

If you already know all of this please disregard.

As already stated the valve on the heat pump will be RH 5/16" SAE male flare so the adapter you bought should work.

You don't want to pull the vacuum using the manifold. The vacuum part of the low gauge is no good for this.

You do want to use a micron gauge and a 5/16" valve core removal tool.

You also want to do a pressure test with nitrogen, So many stories of failed flares but probably would have been found with the pressure test. Just because it will vacuum down doesn't mean it won't leak under pressure.

Don't use the factory flares and torque the connections. You can use a little NYLOG blue on the flare faces but don't put anything on the threads or back of the flares. You will over torque the fittings.

If you have a leak you will need access to R-454B. Don't know if you do.

Good removal tool:

https://www.supplyhouse.com/Appion-MGAVCR-5-16-Valve-Core-Removal-Tool

Here's a great video showing the vacuum procedure:

 

[1320stang]

Okay, this is good stuff. I don't have nitrogen so I looked to see if 75/25 welding gas would work, it doesn't. Pure argon would, but its a heavier gas (I have a TIG bottle with 100% argon).

I got a deal on the units through a local HVAC guy who hooked me up at the supplier, my problem is, he's on one side of OKC and I'm on the other (probably 50 miles). I may call him once both units are installed, wired up and ready to pull down. If his guys have a service call or install up my way, just pay to finalize the install at their conveinience as they have all the equipment and more 454. It would probably be a wash and get done quicker and correctly the first time.

If I had gotten a kit with charged lines, this would be a lot easier I guess, live and learn.