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View Full Version : Drier, Sight Glass, Solenoid valve , which order?



Drew
10-11-2008, 07:16 AM
On a standard cold room, freezer , underbar etc... , In which order should the sight glass, drier and solenoid valve go and does it really matter? This is assuming that the reciever has a valve that can be used to pump the system down. Also assuming that the client prefers that the sight glass is in the plant room so fitting it closer to the TEXV is not possible. The solenoid valve must also be in the plantroom?

taz24
10-11-2008, 12:22 PM
On a standard cold room, freezer , underbar etc... , In which order should the sight glass, drier and solenoid valve go and does it really matter?



In truth no it does not matter




This is assuming that the reciever has a valve that can be used to pump the system down. Also assuming that the client prefers that the sight glass is in the plant room so fitting it closer to the TEXV is not possible. The solenoid valve must also be in the plantroom?

As a rule they are normally placed

Dryer - Solenoid - Sightglass and the reason behind that is simple realy.

The dryer is a filter so is first to remove any rubbish in the system.

The solenoid is just a valve so can go anyware in the liquid line( the closer to the TEV the better on some systems if liquid hammer is to be prevented).

The sight glass is a window into the system and by having it last in the line, you can see if the refrigerant is flowing correctly which also proves if the dryer and mag valve are operating correctly.

taz.

.

dogma
10-11-2008, 12:58 PM
In truth no it does not matter


.

Sry Tas I have to dissagree with that.


The sight glass always goes after the drier. What will happen to the sight glass if the drier becomes blocked??

...and I would put the solinoid first so the dryier can be accessed easier for servicing, although you are right, the sequence is generally drier, solinoid, sight glass, but there is no problem if the reciever has a service valve in putting the solinoid wherever you like.

paul_h
10-11-2008, 02:55 PM
Sry Tas I have to dissagree with that.


The sight glass always goes after the drier. What will happen to the sight glass if the drier becomes blocked??

...and I would put the solinoid first so the dryier can be accessed easier for servicing, although you are right, the sequence is generally drier, solinoid, sight glass, but there is no problem if the reciever has a service valve in putting the solinoid wherever you like.
Even though he said it doesn't matter, he did say the sight glass last is the most ideal. It doesn't matter in the way of system performance so he's right. Preference in the order does have other factors in play, like not making the drier sweat, getting more value out of the sightglass etc.
You can't just snip out one line of a his post to argue that he's wrong, he clearly meant performance won't be affected either way, then explained the ideal setup anyway.
On that note, the drier should be first, you can still replace it by pumping down at the reciever (like the OP stipulated in their senario). A drier after a pump down solenoid will get heaps of condensation on it every time the solenoid pumps down as the refrigerant inside boils of, meaning rust etc.
So taz24s ideal arrangement which he said was best, ie. drier, valve, sightglass. Drier being anywhere on the liquid line, valve and sightglass as close as possible to the TXV.

Drew
10-11-2008, 08:54 PM
I have also been told to put the sight glass first , because if the drier does block up and you have installed it second the system will show short of refrigerant and a technician who does not know to check for a blocked drier might treat the fault as a gas leak and possibly landup overcharging the system.

Brian_UK
10-11-2008, 11:56 PM
I have also been told to put the sight glass first , because if the drier does block up and you have installed it second the system will show short of refrigerant and a technician who does not know to check for a blocked drier might treat the fault as a gas leak and possibly landup overcharging the system.
Then he shouldn't be working alone yet then. ;)

dogma
11-11-2008, 04:50 AM
You can't just snip out one line of a his post to argue that he's wrong, he clearly meant performance won't be affected either way, then explained the ideal setup anyway.


Agreed.


My appologies TAZ.


_Dogma-

taz24
25-11-2008, 01:33 AM
Even though he said it doesn't matter, he did say the sight glass last is the most ideal. It doesn't matter in the way of system performance so he's right. Preference in the order does have other factors in play, like not making the drier sweat, getting more value out of the sightglass etc.
You can't just snip out one line of a his post to argue that he's wrong, he clearly meant performance won't be affected either way, then explained the ideal setup anyway.
On that note, the drier should be first, you can still replace it by pumping down at the reciever (like the OP stipulated in their senario). A drier after a pump down solenoid will get heaps of condensation on it every time the solenoid pumps down as the refrigerant inside boils of, meaning rust etc.
So taz24s ideal arrangement which he said was best, ie. drier, valve, sightglass. Drier being anywhere on the liquid line, valve and sightglass as close as possible to the TXV.

I've just come back to this discussion and read the replies.

Cheers Paul.


Agreed.


My appologies TAZ.


_Dogma-

No problem Dogma.
It was a discussion and you were only making your point.

We may not always agree on what is best but while we are talking we are learning. I know I learn from this site most days so as the advert says

Its good to talk.

Cheers anyway..

taz.

Sledge
05-12-2008, 03:18 AM
Then he shouldn't be working alone yet then. ;)

Agreed, needs some more time apprenticing.

JCDARBY
17-12-2008, 07:04 AM
Hi, im a new user but i would put it in the order of drier sight glass then sol valve for a pump down system just to prevent your drier rusting out.

Aik
15-06-2010, 10:48 AM
In truth no it does not matter

Dryer - Solenoid - Sightglass and the reason behind that is simple realy.

.

Why do you placed solenoid before sightglass?

I see Sporlan recomendations where sightglass placed after solenoid, but also saw many system where solenoid placed after sightglass...
If you placed: Dryer - Sightglass - Solenoid, then you'll see only normal/unnormal dryer work.

If you placed: Dryer - Solenoid - Sightglass, then you'll see solenoids hold of refrigerant. But sightglass is the additional distance between solenoid and TEV. When the system stoped, solenoid is closed and liquid refrigerant between solenoid and TEV goes through TEV to evaporator. If solenoid is far from evaporator then large amount of refrigerant may collect in the evaporator and after compressor starting it goes to compressor in liquid phase...
Also if solenoid placed far from TEV then TEV gets hammer when solenoid is openning.

About dryer Sporlan recomendation:

Catch-All Filter-Driers are most effective in the liquid line. Place thefilter-drier immediately ahead of other liquid line controls, such as thethermostatic expansion valve, solenoid valve, and see all miosture Liquid Indicator. When applied in this way, the Catch-All provides maximum protection for the expansion valve and solenoid valve from dirt that may be in the system. If the system contains appreciable
moisture, then this location gives the best results in protecting the expansion valve from freeze-up. If possible, place the filter-drier in a cold location.

taz24
15-06-2010, 01:42 PM
Why do you placed solenoid before sightglass?


If you placed: Dryer - Solenoid - Sightglass, then you'll see solenoids hold of refrigerant. But sightglass is the additional distance between solenoid and TEV. When the system stoped, solenoid is closed and liquid refrigerant between solenoid and TEV goes through TEV to evaporator. If solenoid is far from evaporator then large amount of refrigerant may collect in the evaporator and after compressor starting it goes to compressor in liquid phase...
Also if solenoid placed far from TEV then TEV gets hammer when solenoid is openning.

About dryer Sporlan recomendation:


I agree with what you say.

There is an argument for sight glass / mag valve and one for mag valve / sight glass.

In my opinion the dryer should be first then the other 2 components will be placed in order, best to suit the aplication.

If you want the mag valve just before the TEV then you would not put the sight lass after it, but if you wanted to use the sight glass to tell you if the mag valve has a restriction in it then it could be placed after it.

Horses for courses I spose ;) ;)

The most important thing is for most applications, the posistioning won't effect performance but it will effect diagagnosing issues within the system.

All the best taz

.

Kp3
15-06-2010, 08:14 PM
Drier should always be first in, if mag valve first in line it can shatter the drier core with liquid being blasted into the drier when mag valve opens. It doesnt happen alot but it will then major issues trying to get the core bits out of the system.

I will always go drier sightglass then mag valve

cadwaladr
15-06-2010, 11:24 PM
Drier should always be first in, if mag valve first in line it can shatter the drier core with liquid being blasted into the drier when mag valve opens. It doesnt happen alot but it will then major issues trying to get the core bits out of the system.

I will always go drier sightglass then mag valvei agree you risk drier probs and drier as close to receiver or condensor if no receiver .

lawrence1
16-06-2010, 07:46 AM
Drew,
I agree with Kp3,,,Drier/Sightglass/Solenoid.
I was taught that when Noah was loading the ark.

Peter_1
16-06-2010, 11:50 AM
Why we install an SV after drier when using pump down: if you should install drier after SV, then the drier will become cold after each pump down and it will therefore rust (driers are made of steel) very fast.

Normal situation...at standstill,it can dry out the liquid in the drier.

doormaster2008
16-06-2010, 05:43 PM
well guys,i would put sight glass,drier then solenoid.i have seen through experience what can happen when an apprentice is sent out on his own at an early age.its alright saying they should know what they are doing but these firms want them out earning as soon as possible.they might know it all but at times the brain does;nt control their hands.very clever but cant do the job.