Traulsen, TXV's but no receiver

[Capz]

I've been taking note lately, seeing many original Traulsen units using TXV's, R404, but no receiver and in a few cases, no sight glass. It was always my understanding, a liquid receiver is necessary when a TXV is used for metering. Can anyone enlighten me? Is this just Traulsen cutting corners, or figuring receivers not necessary for indoor equipment with relatively stable ambient temperatures?

[2sac]

Not necessary. Single circuit. They're not pumping the units down. Just a critically charged unit with better pull down capability than a cap tube. Sight glasses cost money.

[trippintl0]

And if you really wanna get a discussion going, explain why they always pipe the driers vertically with the outlet at the top? Now when it comes to cap tubes, I've heard many say you need the drier outlet at the bottom to maintain a liquid seal. Traulsens typically use TXV's, but with drier outlet on the top, it makes you wonder how it is they work so dang well? (I'm a fan of Traulsen equipment myself.)

[Capz]

Seeing it on 10' prep tables with dual evaps, two txv's

[Capz]

Not necessary. Single circuit. They're not pumping the units down. Just a critically charged unit with better pull down capability than a cap tube.

Seeing it on 10' prep tables with dual evaps, two txv's.

In fact, see a few newer models with liquid solenoid. But honestly can't recall if that one had a receiver or not.

[2sac]

Seeing it on 10' prep tables with dual evaps, two txv's

What I meant by dual circuits is like a table with a well, running med and low temp circuits. What you're describing is no different than having 2 evaps with dual cap tubes, which Traulsen has also done.
I would bet the unit with the solenoid is definetly a pump down.

[ammoniadog]

You will rarely see an air conditioner with a receiver, but lots of them have txv's. An air conditioner is a type of refrigeration system. How does that work?

It is all about having a solid column of liquid going to the txv. To check that, look for subcooling. You don't need a receiver or a sight glass to measure it.

[trippintl0]

I worked on a Traulsen reach-in dual temp recently that used a single compressor. Refrigerator and Freezer both had evaporator with TXV. Liquid line solenoids allow each section to run independently. No receiver also. It was set up a little differently than most Traulsens, with evaporators on the left side of the box inside the wall. The left panel of the outside of the cabinet was removable for service.

[MicahWes]

And if you really wanna get a discussion going, explain why they always pipe the driers vertically with the outlet at the top? Now when it comes to cap tubes, I've heard many say you need the drier outlet at the bottom to maintain a liquid seal. Traulsens typically use TXV's, but with drier outlet on the top, it makes you wonder how it is they work so dang well? (I'm a fan of Traulsen equipment myself.)

I've never really bought into the whole idea that a tiny little liquid line drier in a cap tube cabinet needs to be pointed down to maintain a "liquid seal" at the cap tube.

[mike1020]

A lot of the old traulsons I have use a reciever, sight glass, but have cap tubes

[VTP99]

A lot of the old traulsons I have use a reciever, sight glass, but have cap tubes

Sounds like someone is installing the wrong condensing units.

[Capz]

You will rarely see an air conditioner with a receiver, but lots of them have txv's. An air conditioner is a type of refrigeration system. How does that work?

It is all about having a solid column of liquid going to the txv. To check that, look for subcooling. You don't need a receiver or a sight glass to measure it.

I certainly understand these basics. I was just asking....but let's say the Traulsens with this design are under a high load and the txv's are flowing larger amounts of refrigerant to maintain SH? Still no need for a liquid receiver?

Why does Copeland offer fractional indoor condensing units with or without the receiver? In this case, a 3/4hp skid? What would be a good example of where a condensing skid with a receiver be used if not necessary on a 10' prep table with two evaps?

[VTP99]

[QUOTE=Capz;15194641]

Why does Copeland offer fractional indoor condensing units with or without the receiver?

Most the time I find units with receivers using txv and units without using cap tubes.