Do valves affect flow rate significantly?

I'm considering using a few valves to allow me to easily "disconnect" some of my hoses to the CPU block and rad so that I can easily remove the motherboard tray. Do the valves from Home Depot, 1/2" ID to match the rest of the system, have a significant affect on the flow rate?

A 1/2" ball type valve should have no effect on flow. I am assuming that is the type you are referring to?

I'm actually not even certain which type I'm refering to. I just want a valve that will let me disconnect tubing after it so that when I remove the motherboard from the case, I don't have to a full drain and disconnect.

As long as they're open. heh sorry i had to.
No they wont have any real effect just don't get any 90 degree bends or anything.

the fast disconnect type you are refurring to do impact flow a good bit.
the ball valves some of us use only add minor length to the system but where the fluid flows through it is the same diameter as the surrounding tube so it doesnt effect flow all that much.
what you are asking about has varing parts that present edges for the water to "snag " on

Thank you for the responses. If the fast "disconnect" part is the same diamater as the tube itself, there should be no issue though, correct?

deam said:

Thank you for the responses. If the fast "disconnect" part is the same diamater as the tube itself, there should be no issue though, correct?

Click to expand...

It all depends on the type of valve being used in the quick disconnects. If they are using a ball type valve and are full diameter through the quick disconnects with no restrictions, then you shouldn't have any appreciable restriction. If the quick disconnect uses a butterfly valve then you will see some extra flow restriction. Eheim makes some excellent quick disconnects that use full opening ball valves on each side of the quick disconnect, but they are kind of pricey. IMO they are worth it though, if you want to use quick disconnects and have enough room to use them in your application. The ones I have on my fish tanks fit 12mm ID (16mm OD) tubing and are around 6 inches long when coupled together.

EDIT: That size Eheim tubing corresponds to 1/2" Tygon or silicone tubing

I used these valves and quick disconnects, the only drawback is they add length to your loop. The only coolant I lose is from the block and 2 short lines. Another valve would prevent even that lose but they can be bulky. They are available at Lowes or Home Depot.