brian3b

Does the chart on this graph (http://www.danze.com/products/pdfs/D151000_ss.pdf) mean that if my water pressure is 80 psi, this valve will put out about 19gpm? B/c I was just told that 1/2" water supplies and 1/2" valves would only put out 3-5 gpm, tops. Can someone please clarify? Thanks!

ironrange

Well if the chart says it does it must be true! So that means you should be able to run over seven 2.5gpm shower heads full force off one 1/2" shower valve then. Highly doubtful. Thermostatic valves will put out more gpm vs. a pressure balanced valve. As long as you figure in your friction loss from type and length of pipe and fittings and it all works out you may be ok, yet you already did an actual gpm test from your existing 1/2" valve right, didn't equal 19 gpm did it? I think you already know the answer to your question.

brian3b

Understood... but what I'm asking is that if this valve is "capable" of such output, and my current water supply is "capable" of 12gpm, would it be reasonable to assume that this valve can handle 12gpm and I can run 4-5 heads at once (assuming 2.5gpm per head)?

majakdragon

Brian3b. Since you won't take anyones advice or knowledge on this subject, may I suggest you run all your lines with the heads connected and then turn them on. Once you find out if it serves your purpose or not, you can correct the problem and finish your walls. "Capable" does not mean it will do what you want it to. In your other posts, I have not seen you mention the capacity of your water heater. just another thing to work out for your new shower. Sorry if this post seems hard, but what it says on paper, is not always what you get through the pipes.

__________________
If you have never made a mistake, you haven't done much.

brian3b

It's not hard, I appreciate the responses and I really don't mean to sound ungrateful at all. But here's the deal... I'm very analytical and to me these numbers HAVE to mean something. Otherwise, why would they be published? Sure, I understand that b/c it says 19gpm, there are circumstances that make that number vary one way or the other. But at the same time, I find it hard to believe that one person tells me 12gpm tops from a top of the line Kohler 3/4" thermostatic valve, yet I find a 1/2" thermostatic valve that indicates it can process 19gpm. That's a HUGE difference and it makes me wonder. I could understand if it was close, but those numbers aren't even close and don't add up no matter how you look at it.

I don't think Danze, or any other of these manufacturers would be in business if they over-inflated their numbers so drastically. Certainly there are standards or someone or something that oversees these GPM claims from these valves.

Like I said, it's not that I don't believe anyone and am not listening, but a "1/2" supply won't work, you need 3/4" inch" doesnt explain WHY, it just says no. WHY won't it work?

I'm sure I'll get a response on this "fine, don't listen to us, you're a hard-headed, thick skulled DIYer who doesn't know anything." And that's cool, b/c you're right. I am hard-headed and I don't know much. But what I'm reading isn't adding up. People say "1/2in won't work, you can MAYBE run 2 shower heads." What are you basing that on? How about something like, "you can only run two shower heads b/c your GPM and the allowances of your valves are such that........." Give me a reason... Or do these numbers these manufacturers are producing that bogus? Should I not pay attention to them?

I appreciate everything, but my research just isn't adding up and I'm trying to find concrete evidence. Thanks for reading and responding, I truly appreciate it. I'd love to buy you guys a round of beers so MAYBE you could talk some sense into me and make me understand.

majakdragon

You have changed some things in your posts. You stated, in your other post, that you tested your supply and got 5 GPM. This would indicate that you "may" be able to operate 2 heads. Was the test done on the lower level of your home? If so, you will lose some pressure and volume on the second floor. Your valves may be "capable" of many things, but not if they cannot get enough water to them.

__________________
If you have never made a mistake, you haven't done much.

brian3b

Incorrect Sir. I never said I tested and got 5gpm. I said "Correct me if I'm thinking too simply here... If I test my flow rate and get 5 gpm, would it be reasonable to assume that I can run two shower heads (at 2.5 GPM)?"

The operative word is "if" in that sentence b/c I was trying to figure out how you guys are coming up with what I can and cannot do. I did say, however, that I tested and got approximately 12gpm in a later post.

soooooo... If I have 12gpm on the floor in which I'm installing the shower, and my valve can produce 19gpm, is it reasonable to assume I can run 4-5 heads at 2.5gpm? Thanks again!

I know I'm frustrating some of you guys and I'm really sorry, I'm really not trying to - I'm just looking for something more concrete I guess... I dont want to install 1 shower head if my capabilities are 5. and I dont want to install 6 or 7 if my supply can only support 4. Make sense?

ironrange

You keep coming up with different scenerios and expect everyone to play along. I'm not playing anymore.

majakdragon

I agree. You are on your own. Wish you the best of luck.

__________________
If you have never made a mistake, you haven't done much.

brian3b

I'm either talking to a bunch of women or a bunch of liberals... I said "What if" trying to get a straight answer out of you guys, then I actually got specific numbers (b/c the "what if" wasn't enough apparently) and now I'm changing my story and trying to get you to play along. Well, you caught me. This is what I do for kicks. Nice work detectives.