r22 conversions

[Phase Loss]

We are going through 2 store conversions right now. R-22 MT/LT Racks to R-407F

Leak check & fix existing leaks

change oil, AB to POE, it took 2 changes to get well into the POE range with a refractometer reading ( http://www.nucalgon.com/products/oils/oil-refractometer )

next up, recover the R-22, replace all high side ball valves vapor/liquid lines (per customer), replace gaskets, change filter driers liquid/suction/oil...add new R-407F.

tweak all valve, pressure control, & EMS settings.

Leak check

It's a 2-3 day deal

[kklobas]

i've read alot of stuff saying on small self contained/close coupled units like a reach in etc... you dont even need to change to POE. just evacuate, vacuum, re-charge to old ref head pressure, check sh,sc and call it good. Anyone having luck with this. Described in refrigeration for ac thechs book.

[technician57]

I used MO99 (R438) on about a dozen empty systems last summer. All is well. As a drop in it reminds of R409 replacing R12 in the nineties. I knew they'd come up with a drop in at the right time (Dupont in charge here or what). Even with the problems of large Trane scrolls that came up (corrected with high wattage crankcase heaters) it's a bargain and easy.

Use the blue can not the green one.

[icemeister]

That's what I have been apart of doing. Oil done ahead of time. And it takes 3 changes to get to 98% I believe they want to see. I might have that % wrong. U have to use a refractometer to check it after each oil change.

Doing the oil changes ahead only makes sense because you know you'll have to do it eventually...unless the store is closing or planning a major remodel. The old standard for POE concentration is still 95%, but that was established way back in the early 1990s when the manufacturers really didn't have a good handle on how much mineral oil could be tolerated in a system. RobY was involved in this at the time and has commented on this numerous times, adding that much higher MO concentrations will work well with HFC refrigerants and that they're shooting for a goal of 50%, so only a single oil change would be needed.

Then you start to do all seals that can be done live with old gas like schraders and llsvs gaskets. Then once you take the rack down you get the rest of the seals. Prior you have to also leak check a lot and try to get as tight as possible. You have to pull 500 microns before you put the new gas in. Then once you get new gas in, you still will find leaks.

The way I understand it is the new gas has smaller molecular structure and this is the reason for all this work needed. Depending on the flavor of new gas, you will also be looking at new txv heads. I was a part of one here in Dallas. Did not do it all but was on the job helping. Did several up in MI before coming down here. Much of it depends on customers specs they set forth obviously. Recommision is the next step resetting all superheats and any valving manipulation. Bear in mind product will remain in fixtures and boxes, so the down time is critical. Its a lot of work in a short amount of time. Stage all material, plan the execution. This is critical to a smooth job. Just don't like the idea of doing such a task under the gone. The chains will most likely plan the work in a similair way as explained. Just too much to risk waiting for a loss.

It's been widely discussed that the leaking seal issue is primarily due to their reaction to the presence of R22 (or any blend containing R22), causing them to swell. If the R22 is removed, they'll shrink and start to leak. I think changing seals before changing the gas might be taking a risk, but all I know is they will shrink quickly. I really don't have an idea of how long it takes them to swell up.

So are we mainly talking about shraders and O-rings, or are other types of seals require replacing? IOW, On a typical market refrigerant retrofit, what seals are the main culprits?

[alpharetta]

what sort of complete list of seal need to change for retrofit MO to POE in any system
I've never done it so far.

thanks

[alpharetta]

what sort of complete list of seal need to change for retrofit MO to POE in any system.
I've never done it so far.

thanks

[Dowadudda]

Like Matt just said Ice. Customer is requiring ball valves and stuff. I did not understand the swelling and just read more about that, your right on.

Its a pretty big job in short time frame for a typical store, with a few guys. Its not a cake walk.

Its gonna be a lot of work for a long time all over the country.

[Workin4TheMan]

We had a meeting with the owner of a large reclaiming/recycling company and there were two shocking items he brought up. The Gov plan counted on a huge jump in returned gas around this time due to the "hack" changing colors and actually starting to reclaim the "gold" and turn it in. His outlook "yeah, not gonna happen IMO. Once a a hack, always a hack." OSh*t now what?
The second being the new blends do not work for flooded evaps due to fractionalization, Mr.Heavytonnage start worrying. A Dupont chemist never told him this so he never told us this......."there is nothing to replace 22 in flooded evap applications. No we are not working on one, if we were to start today at our pace it would be 15 yrs till it hit the market."

[jpsmith1cm]

So are we mainly talking about shraders and O-rings, or are other types of seals require replacing? IOW, On a typical market refrigerant retrofit, what seals are the main culprits?

Older sporlan solenoid valves get changed.

SORIT valves get changes.

SPORT A8 valves typically don't need it, but we've got kits there just in case.

Oil system o-rings get changed.

Sentronic sending unit o-rings get changed.

Here's the BEST part... Some of the older ball valves will leak like a mad mother.

[icemeister]

This is good stuff.

Here's a few more questions for you:

Apparently then, the ball valves (older ones in particular) are a major problem area, but I think it's important to know why they're being replaced rather than repaired or upgraded...and are the leaks occurring at the stem, the ball, or both? I know Henry has a stem seal repair kit, but I'm not up on the others out there.

It sounds like the owners typically have a blanket ball valve replacement requirement. How necessary is full replacement over repair? Do the new valve's seal materials resist swelling from R22 so you can safely change them out ahead of retrofit day? If they did, wouldn't that save a boatload of time and effort?

Also, it looks like most of the work is done in the compressor room with not much to do at the cases other than possibly the shrader cores. How many shraders do you find actually leaking after a conversion?

Are the conversions done quickly enough so the cases don't need to be pulled, or do you just need an extra guy to keep the store manager calmed down?

[Cli-Max Indoor Air]

It's $667 here + tax

[jpsmith1cm]

This is good stuff.

Here's a few more questions for you:

Apparently then, the ball valves (older ones in particular) are a major problem area, but I think it's important to know why they're being replaced rather than repaired or upgraded...and are the leaks occurring at the stem, the ball, or both? I know Henry has a stem seal repair kit, but I'm not up on the others out there.

It sounds like the owners typically have a blanket ball valve replacement requirement. How necessary is full replacement over repair? Do the new valve's seal materials resist swelling from R22 so you can safely change them out ahead of retrofit day? If they did, wouldn't that save a boatload of time and effort?

Also, it looks like most of the work is done in the compressor room with not much to do at the cases other than possibly the shrader cores. How many shraders do you find actually leaking after a conversion?

Are the conversions done quickly enough so the cases don't need to be pulled, or do you just need an extra guy to keep the store manager calmed down?

We try to avoid replacement due to labor costs. These are bid jobs and that's all we're getting and we typically don't bid to replace the ball valves.

I believe that the ones that I see leak the most are Superior valves. The ones with a seal-cap that must be removed before the valve can be accessed.

The newer ball valves don't seem to be as much of a problem. Maybe a packing tightened up here or there, but easily repairable.

The old ones?? Get the torch out.

[Workin4TheMan]

We try to avoid replacement due to labor costs. These are bid jobs and that's all we're getting and we typically don't bid to replace the ball valves.

I believe that the ones that I see leak the most are Superior valves. The ones with a seal-cap that must be removed before the valve can be accessed.

The newer ball valves don't seem to be as much of a problem. Maybe a packing tightened up here or there, but easily repairable.

The old ones?? Get the torch out.

How are you handling the leaks after the fact? Are any items not replaced in the quote excluded from warranty?

[Dowadudda]

JP, so ball valves and what not, your customers are not requiring it?

[jpsmith1cm]

JP, so ball valves and what not, your customers are not requiring it?

Nope. Not as of yet.

[jpsmith1cm]

How are you handling the leaks after the fact? Are any items not replaced in the quote excluded from warranty?

Customer provides refrigerant for the job. We always order extra and leave it onsite for a week or two.

We provide the labor and any materials.

Excluded? Our customer doesn't know the meaning of the word...

[Gnarly]

Guys,

has anyone used BMP 438 to replace R-22 in any racks? We have a customer here who's considering it. Aside from the 20% loss in capacity are there any other draw backs?

[jpsmith1cm]

JP, so ball valves and what not, your customers are not requiring it?

Adding to this because I'm not sure I completely answered your question.

We aren't required to change the ball valves as yet.

We ARE required to change oil (we also must provide an oil analysis report from national), o-rings, driers, filters etc. Pretty basic stuff, I think.

I don't have the requirements in front of me nor do I have them memorized, but that's about the nutshell of it.


Icemeister, I forgot an o-ring that NEEDS to be changed... Remember those Alco TEVs that have an O-ring sealed strainer? Ya better get them, too.

[jpsmith1cm]

Guys,

has anyone used BMP 438 to replace R-22 in any racks? We have a customer here who's considering it. Aside from the 20% loss in capacity are there any other draw backs?

Can your equipment afford a 20% loss in capacity?

[Gnarly]

The low temp system can as they have removed 1/3 of the equipment in the store.