Silly Question - Water Flow Direction

[Mark Melvin]

Hi Guys,

I'm replacing the water lines on my laser and I am starting to second-guess myself on the plumbing.  I have Googled for awhile and surprisingly have found no conclusive answer on this...  Which direction should the water be flowing?  I currently have it flowing first to the laser light outlet (negative end), through the tube to the positive end, and back to the reservoir.  Is this correct? 

If so, why is the cooling coil at the "hot" end of the laser?

Thanks,

Mark.

[j. eric townsend]

On 8/4/15 23:22, Mark Melvin wrote:
> Hi Guys,
>
> I'm replacing the water lines on my laser and I am starting to
> second-guess myself on the plumbing. I have Googled for awhile and
> surprisingly have found no conclusive answer on this... Which direction
> should the water be flowing?

Which brand tube and didn't it come with labels?

--
J. Eric Townsend, IDSA
design <http://www.allartburns.org>
hacking <http://www.flatline.net>
consulting <http://www.functionalprototype.com>

[Mark Melvin]

On Tue, Aug 4, 2015 at 11:41 PM, j. eric townsend <j...@allartburns.org> wrote:

On 8/4/15 23:22, Mark Melvin wrote:

Hi Guys,

I'm replacing the water lines on my laser and I am starting to
second-guess myself on the plumbing.  I have Googled for awhile and
surprisingly have found no conclusive answer on this...  Which direction
should the water be flowing?

Which brand tube and didn't it come with labels?

Hi Eric,

Yes, it is labeled - the "Water Outlet" is the positive end with the cooling coil (the opposite end of the laser light output), but I am questioning now whether this means "the water comes out here" like I took it to mean when I assembled it, or "connect this to the 'water outlet' on the chiller".  

Mark.

[j. eric townsend]

On 8/4/15 23:22, Mark Melvin wrote:

> Hi Guys,
>
> I'm replacing the water lines on my laser and I am starting to
> second-guess myself on the plumbing. I have Googled for awhile and
> surprisingly have found no conclusive answer on this... Which direction
> should the water be flowing?

I just checked -- my RECI has "water outlet" on the end next to the
laser output.

[Mark Melvin]

On Tue, Aug 4, 2015 at 11:53 PM, j. eric townsend <j...@allartburns.org> wrote:

On 8/4/15 23:22, Mark Melvin wrote:

Hi Guys,

I'm replacing the water lines on my laser and I am starting to
second-guess myself on the plumbing.  I have Googled for awhile and
surprisingly have found no conclusive answer on this...  Which direction
should the water be flowing?

I just checked -- my RECI has "water outlet" on the end next to the laser output.

Thanks for checking.  Dang.  That confuses me even more...

I have a Chinese tube (60W), but I would think these should all be installed the same, should they not?  

[Steve Baker]

Most lasers (don't know if it's all of them) and certainly the RECI tubes
require that the water goes into the tube at the end where the red wire
connects - and leaves the tube at the end where the light comes out.

The CW-5000/5200 chillers are labelled with an OUTLET and an INLET.

You should connect the OUTLET of the chiller to the INLET of the laser
(the end with the red wire) and the OUTLET of the laser (where the light
comes out) to the INLET of the chiller.

(I wrote IN and OUT on my laser tubes with a sharpie pen so I wouldn't
forget if the stickers ever fell off...which they did!)

-- Steve

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-- Steve

[Mark Melvin]

Thanks, Steve.  I'm going to switch mine.  I think I have been running it in reverse.  I've never been happy with the power I am getting out of this.  I don't know if this will help or not but it makes sense to me as an engineer to run the water the way you guys describe (which is why I am questioning mine...).  Who knows what they intended when they labeled this thing!?  Thanks for the confirmation guys. 

Mark.

To view this discussion on the web visit https://groups.google.com/d/msgid/lasersaur/bb2515da0f6254d988e8869a8653c718.squirrel%40webmail.sjbaker.org.

[Mowcius]

I believe this is so you're less likely to stress the mirror end if you end up with quite a hot end lens/mirror and very cold water coming from the chiller.

I doubt it makes too much difference in normal operation.

Rob

---

From: Mark Melvin <mark....@gmail.com>
To: lase...@googlegroups.com
Sent: Wednesday, 5 August 2015, 5:29
Subject: Re: [lasersaur] Silly Question - Water Flow Direction

To view this discussion on the web visit https://groups.google.com/d/msgid/lasersaur/CAGYD0y6mdkyjfHiYjYd9b72-Hm-MkugQSfbKpaHCRPmWc4JeRg%40mail.gmail.com.

[Wolfgang Kraft]

Hi,

from my understanding it should be filled from the lower connection and the
outlet is the higher connection.

That way it is ensured, that the tube is always filled with water.


Wolfgang

------
In Antwort auf die folgende Mail

From: "'Mowcius' via lasersaur" <lase...@googlegroups.com>
To: "lase...@googlegroups.com" <lase...@googlegroups.com>
Cc:
Subject: Re: [lasersaur] Silly Question - Water Flow Direction
Date: Wed, 5 Aug 2015 12:08:11 +0000 (UTC)


I believe this is so you're less likely to stress the mirror end if you end up with quite a hot end lens/mirror and very cold water coming from the chiller.
I doubt it makes too much difference in normal operation.

Rob

To view this discussion on the web visit https://groups.google.com/d/msgid/lasersaur/210862996.291912.1438776491555.JavaMail.yahoo%40mail.yahoo.com.

[Mark Melvin]

Hi Wolfgang,

Yes - my copious Googling last night also confirmed that.  

I was always under the impression the coil inside was a cooling coil - turns out, water doesn't flow through there at all.  It has something to do with path lengths.

My conclusion is that the direction probably doesn't matter as long as the water outlet is higher than the inlet, but the more popular/conventional direction of flow seems to be from positive to negative (or from the glass coil end to the laser light output end).

Thanks again guys.

Mark.

To view this discussion on the web visit https://groups.google.com/d/msgid/lasersaur/312240912.20150805150636%40WKraft.org.