| Author |
Message |
    
Steven Edward Haun
Member
Username: Stevehaun
Post Number: 145
Registered: 02-2003
| | Posted on Wednesday, December 29, 2004 - 11:37 pm: | 
|
I have been searching the archives regarding the ideal size of copper tubing to use for a herms coil. 1/2" seems to be what most people use. However, I am confused. Is this 1/2" ID (5/8" OD) tubing or is it 1/2" OD tubing (3/8" ID)? |
Dave Witt
Advanced Member
Username: Davew
Post Number: 619
Registered: 03-2003
| | Posted on Thursday, December 30, 2004 - 12:51 am: |
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Steve,
The actual size is 1/2" OD and fittings (flare, compression, etc)are 1/2" when talking soft copper tubing. For copper sweat fittings you need 3/8" to fit over 1/2" soft copper. Hope this makes sense. |
Kent Fletcher
Advanced Member
Username: Fletch
Post Number: 690
Registered: 11-2002
| | Posted on Thursday, December 30, 2004 - 01:30 am: |
|
I use 1/2" OD, which is actually larger than 3/8" ID, Grainger 3P672 is about $38 for 50 feet, but you probably don't need 50 feet, quite a few HERMSers use 25 foot coils. 3/8 OD is too small, the increased head losses mean low flow rates.
For sake of clarity, always refer to the OD size when discussing copper tubing. |
Joe Rovito
Member
Username: Joez8
Post Number: 131
Registered: 03-2003
| | Posted on Thursday, December 30, 2004 - 07:13 am: |
|
Keep researching ! It is not intuitive.
In fact it is downright confusing till you get the hang of it.
Pipe & Tube have different fittings:
Compression & Flare for tubing
Sweat and NPT (thread) for Pipe.
===================================
1/2" soft copper tubing, as used for herms coils is actually 1/2" O.D.
1/2" copper pipe is 5/8" O.D. - Go Figure !
I.D. varies between 0.527 --> 0.569" dependent on type.
My Herms uses 50' of "1/2" tubing. I connect to my "1/2" pipe fittings with a 1/2" compression to 1/2" NPT adapters.
Some Links:
http://www.keidel.com/mech/pvf/pipe-cu.htm
http://www.gizmology.net/pipe.htm
http://www.plumbingsupply.com
(Message edited by joez8 on December 30, 2004) |
Steven Edward Haun
Member
Username: Stevehaun
Post Number: 147
Registered: 02-2003
| | Posted on Thursday, December 30, 2004 - 01:51 pm: |
|
My entire system (hoses, full-port ball valves, quick disconnects, couplings, pipe, etc) is 1/2". If I use 1/2" OD copper tubing for my herms coil, won't that have significantly higher resistance than the rest of my system? Is that a problem or do you have to decrease your flow so much to prevent compacting your grain bed that the increased resistance of the herms coil is insignificant? |
Bill Pierce
Moderator
Username: Billpierce
Post Number: 1626
Registered: 01-2002
| | Posted on Thursday, December 30, 2004 - 03:28 pm: |
|
Don't sweat it, Steven. The relatively small difference in diameter between 1/2 in. I.D. pipe and hose, and 1/2 in. O.D. copper tubing for the recirculation coil is not going to cause problems. |
Kent Fletcher
Advanced Member
Username: Fletch
Post Number: 693
Registered: 11-2002
| | Posted on Thursday, December 30, 2004 - 06:47 pm: |
|
Steven, you already have several points of restriction tighter than the .436 ID of 1/2" OD tubing. Your QDs have a smaller ID, any barbed fitting does. Besides, going larger than 1/2" OD tubing is actually less efficient in a coil of reasonable length, because of the ratio of volume (per foot of tubing) to contact surface area. |
Belly Buster Bob
Senior Member
Username: Canman
Post Number: 1953
Registered: 02-2003
| | Posted on Thursday, December 30, 2004 - 10:57 pm: |
|
just to toos a curve...I use 3/8 tubing. Pipe can also be used for a coil...fill it with sand and bend away |
Brews and Views Archive 2004 
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