Liquid Line Strainer Question

[man from trane]

On a combo low/medium-temp Source rack I've got a few of my medium temp evaps starving. Several of them have frosted distributors and are running SH around 35 Deg F. Some box temps not holding. If it were only one evap with a problem I might suspect a TXV issue, but the starving evap issue is gradually spreading throughout the store. Someone stole my gauges :mad: so it's going to be a bit before I can a new set shipped here, but I am suspecting the liquid strainer at the rack is becoming restricted. I have never cleaned it and I'm sure the last guy who had the account didn't touch it. How often should that be done?

There is no subcooler for the medium temp other than right before each TXV the liquid line is attached to the suction line. The rack condenser is corroded by salt so I only get about 8 Deg of subcooling for the system (Liquid temp vs. condensing temp.) For some reason the liquid line is insulated throughout the store. I don't get that. :confused: Since it's always warmer outside I would think it would get some subcooling just by removing the insulation. There is no temp difference across the strainer. The liquid temp at the rack was 100 Deg and felt warm at the entrance to the TXV I checked yesterday, but I suspect flashgas at the TXV entrance.

Here's my question: The strainer (It looks like a strainer :o) has a bolted on cover with iso valves on each side. What's inside it? It is just a screen basket or it there a special dehydrating element inside? How do I clean it? I know I'm not going to hose it off with water. :eek:

The Sporlan See-All on the low temp side after the subcooler shows full and dry, but that's subcooled so it would be even if the strainer is restricted.

[jpsmith1cm]

You only have one set of gauges??!:eek: I couldn't survive without 3.


That is probably a drier shell. Depending on size, you will need between 2 and 4 or more cores to install.

More details. Typically, my racks have a sporlan "catch-all" type shell with a flanged lid. isolate, recover and open it up. Inside is pretty self explanatory. I carry 12 or more RC 48 size cores at all times. Those are the standard size around here.

THERE ARE OTHER SIZES!!!

Read the sticker on the shell and get what you need before openng it.

I use the supplied gaskets between the drier blocks to prevent what amounts to bypass.

[man from trane]

You only have one set of gauges??!:eek: I couldn't survive without 3.


That is probably a drier shell. Depending on size, you will need between 2 and 4 or more cores to install.

More details. Typically, my racks have a sporlan "catch-all" type shell with a flanged lid. isolate, recover and open it up. Inside is pretty self explanatory. I carry 12 or more RC 48 size cores at all times. Those are the standard size around here.

THERE ARE OTHER SIZES!!!

Read the sticker on the shell and get what you need before openng it.

I use the supplied gaskets between the drier blocks to prevent what amounts to bypass.

Thanks! Glad I didn't open it up yet. So there are several cores inside that are non-serviceable? I will get the numbers and order them.

I'm a pretty small operation at this point (1 supermarket and a few A/C units) so 1 set of gauges was working well.

Refrigerant Recovery in the Caribbean? :rolleyes: No one will take the old refrigerant and they won't let you ship it off island. We're a bit behind the times, I'm afraid. I watched a guy blow 7# of R-22 into the atmosphere a couple months ago. I also watched a guy crack a schrader valve on a fully charged 40 ton Trane condenser that was to be cut up and removed and go to lunch. These were pros with a well known company here. The EPA would have a ball. :D

I thought I would pump the system down and use my gauge manifold to bypass any liquid to the low side. That would leave only a little low pressure vapor in the drier and piping.

As far as starting it back up, maybe a little diminimus purge? :cool:

[jpsmith1cm]

Your method will work. You could also run the compressors to a lower pressure to pump to zero. I've done that when I was too lazy to go get the recovery machine.

Another tip. Keep a small propane torch handy. All that liquid boiling builds a lot of frost, a torch speeds things up nicely.

[man from trane]

^ Thanks, I feel dangerous now.

Up for a laugh? I found this site while searching for "Sporlan". Apparently some Chinese company is making Sporlan knock-offs and their Engrish is hilarious. I'm tring to figure out what they mean by "The sensing elements are sealed with advanced knife-tightening technology. It is both artistic and away from leakage" regarding TXV power elements. I've never used a knife to tighten a power element but what do I know? :eek: :D

http://www.sporlan.net/product.asp?id=193&classid=105&action_i=105&type=b

[man from trane]

:o

I went back to get some numbers off the "strainer". Decided to take off more covers (it's an outside rack) and get a better look at things. There's a sticker in an awkward place I could only see after stepping inside that says it's an Alco STAS-14417T filter drier shell that takes 3 size 48 cores. That was easy. :rolleyes:

Looking around a bit more, 2' downstream is a bubbling sightglass on the medium temp liquid line. :eek: There's also about a 7 Deg temp drop across the shell. So the system is starving because the cores need replaced. I wonder how long it has been like that. Now I just need to find someone to ship me some cores. I could call those guys from China in the link above...:D

[jpsmith1cm]

I would get extras and do another change in 24 to 48 hours.

I change cores at 5 psi differential and after any major work. Check at least once a year.

[crackertech]

Like jpsmith said best order extra I carry 6 to 8 48's all the time and at least
3 of the 36's.:)

[Andy Schoen]

I had a chance to meet with some of the folks from Sikelan/Hangzhou during the China refrigeration show in Shanghai last April. When they learned I was from Sporlan, they were very happy to show me their products and wanted my opinion on them.

They make also make copies of Alco and Parker products.

The number of me-too product manufacturers at the China show was mind boggling. I lost count of the refrigeration component manufacturers I saw there. :(

[man from trane]

I had a chance to meet with some of the folks from Sikelan/Hangzhou during the China refrigeration show in Shanghai last April. When they learned I was from Sporlan, they were very happy to show me their products and wanted my opinion on them.

They make also make copies of Alco and Parker products.

The number of me-too product manufacturers at the China show was mind boggling. I lost count of the refrigeration component manufacturers I saw there. :(

Interesting, and what was your opinion of the parts? They look comparable.

[Andy Schoen]

Interesting, and what was your opinion of the parts? They look comparable.

Not quite ready for prime time. But there were some interesting components on display. For example, the largest refrigerant distributor I've ever seen:

http://www.JAndrewSchoen.com/andyspics/China2008/Big Refrigerant Distributor 04-09-08 Resized.jpg

[Andy Schoen]

And a Saginomiya reversing valve that you won't find on residential heat pump systems... :p

http://www.JAndrewSchoen.com/andyspics/China2008/Saginomiya Reversing Valve 04-10-08 Resized.jpg

[man from trane]

Not quite ready for prime time. But there were some interesting components on display. For example, the largest refrigerant distributor I've ever seen:

http://www.JAndrewSchoen.com/andyspics/China2008/Big Refrigerant Distributor 04-09-08 Resized.jpg

OMG! At that point I thinks it's time for a split evaporator! I'd hate to have to braze that in. :eek:

[A1 Burt]

Man from trane what about united on St.Thomas for getting part's:cool:

[man from trane]

Man from trane what about united on St.Thomas for getting part's:cool:

Funny you should mention that. I just discovered them last night while browsing the 'net! If they can easily get, or already stock what they have in their online catalog then that may solve my parts problems. Shipping should be cheap since they just throw it on the boat or Seaplane. Thanks! :)

[man from trane]

Took apart the shell, the cores smell very metallic (like copper or brass smells). They look ok but the screen was plugged pretty good with a black dust. Is that carbon? Where could that be from? There was also a significant amount of copper colored dust and filings in the bottom of the shell. I expected it to look very clean but it looked kind of cruddy.

I cleaned it up and put it back together without the cores to get them running again. Produce units were freezing up. New high-capacity cores come today so I hope to get time to replace them.

The sytem is running better now than it has in 6 months. :cool:

[jpsmith1cm]

That black stuff could be carbon or copper oxide from brazing without a purge.

Cores don't have to look bad to be bad. It also helps to have a comparison. To show managers, I have busted a core with a wrench. Often, you will see a difference between the original (inside) color and the outer color.

Amazing how a system works better once the valves get liquid!!! I've seen cores with over 100psi drop across the shell.

And nobody else noticed..???

[man from trane]

And nobody else noticed..???

:D This is America's 3rd world, my friend. If it's not on fire, growing mold, or dripping on the floor (someone will slip and sue) they don't notice. There was 1/4" of ice on the back wall of the multi-deck produce display and the unit had been in alarm for 3 hours at 60°. The drive-in dairy box was 49° all afternoon. It's supposed to hold 36°. I wouldn't be buying any milk there today. :eek:

The funny (sad) thing is they have a woman who walks around several times a day and logs all box temps. All the boxes have alarms that go to a central monitoring service. Still it's usually me dialing in from home to be the one who tells them they have a problem.

[jpsmith1cm]

It aint just there.

If a problem doesn't bite some people on the a$$, it doesn't exist.

[MikeySq]

Yeah lets put a chinese knock off part that was built by reverse engineering and quite possibly not with the proper materials, I'm sorry sir you just lost your rack charge due to this valve cracking, hahahah.

A good bud of mine is mechanical engineer doing drilling work in the middle east and he tells me that it's hard to find proper tools and parts locally that are not knock offs, He usually has to wait to get good stuff sent to him from the US. All the same he did bring me back a nice Breitling watch!! haha

as for drier talk a bunch of newer racks around here are using 100 cores on the MT racks so i keep a few rcw100's as wells as some rcw48's

Mike

[fitter33]

Better check down in the cases for driers also.....if there are cut em' out. You don't ned to replace them with new ones. I have seen time after time techs missing those, thinking it's a TXV problem. Check your temp diff. across the drier. Your hands can tell you a lot. My advice would be to check all your screens in the TXV's if they have them, if you had junk at the cores you can bet it's in the system throughout. I use UK-48's in my stores.

I wouldn't run the system w/o cores installed.....get them in asap. The copper dust...like said before could and is most likely from welding over the years w/o a purge. It happens all the time.