New Spir@l - Page 3

FRAGN'STIEN · 07-07-2002, 09:22 PM

WOOT! There out and my order is in

NoSoupForYou · 07-07-2002, 09:55 PM

Sorry Dodge - going 3/8" ID the whole way rather than 1/2" ID tubing and 3/8" ID barbs will most likely only increase flow resistance.

Will you have a pressure drop going from 1/2" to 3/8" - yes. Will this be greater than the pressure drop due to the increased flow resistance in the 3/8" tubing - almost certainly not.

DodgeViper · 07-07-2002, 11:34 PM

NoSoupForYou, All water blocks on the market as of today are using either 1/2" od with 3/8" id or 3/8" od with 1/4" id fittings. No matter how you look at it if you use 1/2" tubing and you connect the 1/2" tubing to a 1/2" od barb with 3/8" id you are causing restriction. Many test have been conducted and nobody can claim 1/2" is better over 3/8". All I did was align what is very obvious keeping the ID the same size throughout the system.

The latex tubing I am use is like you see in labs. It can be purchased in amber or black.

NoSoupForYou · 07-08-2002, 07:35 AM

Dodge, I understand about WB barb connection sizes.

What I am saying is that by replacing the 1/2" with 3/8", you are lengthening the restriction caused by using 3/8" ID from just the barb to the whole tube.

Restrictions aren't 'all or nothing'. The resistance in the loop is not the same as the highest resistance in the loop - it is the sum of all the resistances in the loop.

By reducing the flow diameter from 1/2" to 3/8" you force the water to increase velocity to pass through the restriction. This will cause a pressure loss (as well as increased flow resistance due to the smaller ID and faster fluid flow). However, if you run the whole loop at 3/8", you will have the increased flow resistance from the smaller ID and higher velocity through the whole loop, not just in the barb(s).

gmat · 07-08-2002, 07:52 AM

+1 to that NoSoup.

Hallis · 07-08-2002, 08:01 AM

I agree with Dodge on this point. The water is only going to move as fast as the smallest point in the loop can allow it. When going from 1/2" ID tube to 3/8" ID barbes there is resistance. Basically what ends up happening is the vilosity of the water is slowed down after the waterblock. But actually increaced through the waterblock. Which also makes more backpressure before the block. This backpressure may be restricting flow. And we could argue about it all day. But i'd just as soon have the hose the same ID as everything else.

bigben2k · 07-08-2002, 08:21 AM

Some of ya'll got it partly right...

3/8 id or 1/2 id, they all restrict flow, but the 3/8 id will be a lot more restrictive.

I've looked up plumbing specs, and flow rates, and what I've seen is that 3/8 id is good enough for most people, but those that have a higher flow rate, do benefit from the 1/2 ID, because those high flow rates warrant the use of 1/2 id tubing.

For most of us though, the difference between 3/8 id and 1/2 id, for the low flow rates we have, really doesn't make much of a difference.

What we all need to keep in mind though, is that every part of a cooling system restricts flow and that the biggest restrictor is, by far, the waterblock.

Hallis · 07-08-2002, 08:29 AM

*nods* i knew youd see it my way ben.

Hallis · 07-08-2002, 08:32 AM

Oh Ben send me a PM or email with your email addy if you would

bigben2k · 07-08-2002, 08:40 AM

Quote:

Originally posted by Hallis
Oh Ben send me a PM or email with your email addy if you would

I don't use PM. I'll send ya my add. (I actually check it sometimes!)

DodgeViper · 07-08-2002, 10:41 PM

The water block is the biggest restriction in the entire system. I did not check flow through my new D-Tek TC-4, but I did with my Gemini High Volume block.

At a 12” rise or head my Eheim 1250 pump would deliver 190 gallons per hour. With the Gemini water block attached the pump would deliver 64 gallons per hour. Next was to place the heater core inline. The flow dropped to 60 gallons per hour.

Now with the TC-4 the channels are closer to being 3/8” than the Gemini. This is where I can contribute why my temps dropped 2c over the Gemini. Next was to bring the entire system to match the 3/8” ID / 1/2 OD barbs and why my system now wears 3/8” tubing.

07-07-2002, 09:22 PM	#51
FRAGN'STIEN Cooling Savant Join Date: May 2002 Location: Rathdrum, ID Posts: 380	WOOT! There out and my order is in __________________ This space for rent

07-08-2002, 08:21 AM	#57
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	Some of ya'll got it partly right... 3/8 id or 1/2 id, they all restrict flow, but the 3/8 id will be a lot more restrictive. I've looked up plumbing specs, and flow rates, and what I've seen is that 3/8 id is good enough for most people, but those that have a higher flow rate, do benefit from the 1/2 ID, because those high flow rates warrant the use of 1/2 id tubing. For most of us though, the difference between 3/8 id and 1/2 id, for the low flow rates we have, really doesn't make much of a difference. What we all need to keep in mind though, is that every part of a cooling system restricts flow and that the biggest restrictor is, by far, the waterblock. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

07-07-2002, 09:55 PM	#52
NoSoupForYou Cooling Neophyte Join Date: Jun 2002 Location: NJ Posts: 11	Sorry Dodge - going 3/8" ID the whole way rather than 1/2" ID tubing and 3/8" ID barbs will most likely only increase flow resistance. Will you have a pressure drop going from 1/2" to 3/8" - yes. Will this be greater than the pressure drop due to the increased flow resistance in the 3/8" tubing - almost certainly not.

07-07-2002, 11:34 PM	#53
DodgeViper Registered User Join Date: Feb 2002 Location: Tucson, Arizona Posts: 204	NoSoupForYou, All water blocks on the market as of today are using either 1/2" od with 3/8" id or 3/8" od with 1/4" id fittings. No matter how you look at it if you use 1/2" tubing and you connect the 1/2" tubing to a 1/2" od barb with 3/8" id you are causing restriction. Many test have been conducted and nobody can claim 1/2" is better over 3/8". All I did was align what is very obvious keeping the ID the same size throughout the system. The latex tubing I am use is like you see in labs. It can be purchased in amber or black.

07-08-2002, 07:35 AM	#54
NoSoupForYou Cooling Neophyte Join Date: Jun 2002 Location: NJ Posts: 11	Dodge, I understand about WB barb connection sizes. What I am saying is that by replacing the 1/2" with 3/8", you are lengthening the restriction caused by using 3/8" ID from just the barb to the whole tube. Restrictions aren't 'all or nothing'. The resistance in the loop is not the same as the highest resistance in the loop - it is the sum of all the resistances in the loop. By reducing the flow diameter from 1/2" to 3/8" you force the water to increase velocity to pass through the restriction. This will cause a pressure loss (as well as increased flow resistance due to the smaller ID and faster fluid flow). However, if you run the whole loop at 3/8", you will have the increased flow resistance from the smaller ID and higher velocity through the whole loop, not just in the barb(s).

07-08-2002, 07:52 AM	#55
gmat Thermophile Join Date: Mar 2001 Location: France Posts: 1,221	+1 to that NoSoup.

07-08-2002, 08:01 AM	#56
Hallis Cooling Savant Join Date: Oct 2001 Location: Dallas, Tx Posts: 469	I agree with Dodge on this point. The water is only going to move as fast as the smallest point in the loop can allow it. When going from 1/2" ID tube to 3/8" ID barbes there is resistance. Basically what ends up happening is the vilosity of the water is slowed down after the waterblock. But actually increaced through the waterblock. Which also makes more backpressure before the block. This backpressure may be restricting flow. And we could argue about it all day. But i'd just as soon have the hose the same ID as everything else.

07-08-2002, 08:29 AM	#58
Hallis Cooling Savant Join Date: Oct 2001 Location: Dallas, Tx Posts: 469	nods i knew youd see it my way ben.

07-08-2002, 08:32 AM	#59
Hallis Cooling Savant Join Date: Oct 2001 Location: Dallas, Tx Posts: 469	Oh Ben send me a PM or email with your email addy if you would

07-08-2002, 10:41 PM	#61
DodgeViper Registered User Join Date: Feb 2002 Location: Tucson, Arizona Posts: 204	The water block is the biggest restriction in the entire system. I did not check flow through my new D-Tek TC-4, but I did with my Gemini High Volume block. At a 12” rise or head my Eheim 1250 pump would deliver 190 gallons per hour. With the Gemini water block attached the pump would deliver 64 gallons per hour. Next was to place the heater core inline. The flow dropped to 60 gallons per hour. Now with the TC-4 the channels are closer to being 3/8” than the Gemini. This is where I can contribute why my temps dropped 2c over the Gemini. Next was to bring the entire system to match the 3/8” ID / 1/2 OD barbs and why my system now wears 3/8” tubing.

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