its been awhile...
does it cover all 3 cases?

A - pump -> nozzle
B - pump -> checkvalve -> nozzle
C - pump -> checkvalve<->checkvalve -> nozzle

The two check valves I posted is the most commonest valve used on the WI community.

Whoosh, any objection using them for my test?

Abner will post up the section drawing of his Swagelok check valve - also commonly used on the water injection application - Please comment when drawing becomes available.

OK from looking at the picture above you will have a pressure drop due to the "orifice" of the valve. This creates a "venturi" effect which will cause a pressure drop. How great the drop is unknown with out extensive formulas that I no longer remember.

I can only find cv and no-cv. I think it is good enough - 27MB each !!! :D

Abner is this the check valve you use? sorry file is too big to upload.

should I do the test or not?

Seemed to have some mind changing since the drawings regarding my first statement of pressure drop. :confused:

Do the test. I want real world results here not just some paper and formulas.

Wonderful! That's an industry standard. If you are using a 1/4" npt valve it has a Cv of .35. If you tell me what the low rate wil be in gpm, I'll tell you what the pressure drop across the valve will be. On Wednesday because I'm done with calculating today!
The formula is ^P=(Q/Cv)(Q/Cv) p/62.4
Do the test!

i'm been sitting infront of the monitor the whole day. Itching to do to the back to do some experiments :p

I guess post the set of videos from awhile back and i'll do another set of experiment, this time i'll just take pics

i have a tabulated table from swagelok posted

Abner,

I have found all three!!! {thumbup} {thumbup}

{thumbup}

:( ...no experiments to do

OK, abner, I lost them again. :lol: :lol: :lol:

here are the pic/data for the checkvalve that Richard will be posting the videos on

http://img1.putfile.com/thumb/2/5002075614.jpg

X-sectional view

http://img2.putfile.com/thumb/9/24618581715.jpg

Pressure drop Vs. flow table

http://img2.putfile.com/thumb/9/24618581865.jpg
http://img2.putfile.com/thumb/9/24621471367.jpg

it's hard to tell what's what in the diagrams of the check valves posted.

Here are a couple of pics of a checkvalve in the water line to the intercooler sprayer on an 03 Evo. You can clearly see the ball on one side, and the spring on the other. I hooked up a little rig I have with a bicycle pump, vacuum tubing, tee and pressure gauge. The spring is a 3# spring.

http://i124.photobucket.com/albums/p...Picture091.jpg
http://i124.photobucket.com/albums/p...Picture092.jpg
http://i124.photobucket.com/albums/p...Picture093.jpg

This is the type check valve I see in Richards diagram in question with the 20# check valve. And I still say this type of check valve will cause a pressure drop equal to the spring pressure. The differential pressure across the ball and seat has to equal 3#'s to get check valve to crack open, and it maintains a 3# drop even after it's open, at various pumping rates. The differential has to equal 3#'s to keep it open. So if you have no pressure on the backside or downstream of the ball, it opens at 3#'s. If you had say 10#'s of pressure on the backside of the ball, I'd have to pump 13#'s of pressure with the bicycle pump to get it to crack open and stay open and flow.

Are you guys trying to tell me once the seat is broken and the valve cracks open, the pressure drop will be dependent upon some Cv value alone????? Nope, it's going to be the pressure drop caused by the orifice (Cv) PLUS the spring pressure. At low flows, it'll be damn near 3#'s, at higher flows, it could be considerably more. But never less than 3#'s.

If this is the type of check valve for the test, by all means run the test.