View Full Version : Does It Matter Which ASV?

01-24-2016, 08:03 PM
Hi, just wondering which style of automatic shut off valve is more dependable.

The straight through, or U-type Payne.

Currently I am using the straight through, and have noticed that it hammers when I use the by-pass valve to flush the membrane. It does not hammer when the flow restrictor is in use.

I am planning on swapping them around to see if it's the through valve that is faulty.


01-24-2016, 08:42 PM
I don't know which type my is. I've had 3 in use, and had one fail once. It didn't "hammer", it just stopped shutting off the flow. On the other hand, I've had the system "hammer" before, but I can't remember what the problem was.

This is the type I've been using:

Not much info, but I did find this: http://www.reefcentral.com/forums/showthread.php?t=1293478

01-26-2016, 12:59 AM
Thanks Mika,

I was using one of those straight through ASV like the one you have pictured.

My inlet water pressure is 65psi. The through ASV was stopping the water flow at 40psi.

So, in my brilliance, I decided to install an inlet booster pump that would boost inlet pressure to 70-100 psi. Thus increasing my outlet pressure to my ice maker. Good in theory only. The electric ASV for the in line boost pump limited outlet pressure to 35psi.

So, I removed the booster pump and electric ASV. I also swapped out the straight through ASV for the round Payne type ASV.

I am happy with the results, so far.

Outlet pressure is now 46psi when ASV stops water flow.

This is good as I will be splitting the after pre-filter line into one for ice maker and one higher output for aquarium water when needed. I will just be changing out sediment and charcoal filters more often.

The hammering was being caused by pressure pump cavitation.

T :biggrin:

01-26-2016, 02:24 AM
Ah ha! :)

01-26-2016, 08:39 PM
My RODI came with the ASV that's pictured in Mindy's post. I could never get it to work properly from day 1. No hammering issues and the mechanical float valve shut the product water off just fine, but the ASV would continue to allow waste water through. Last year I decided to remove the darn thing since I never used it anyway. I only make water when I'm home, don't trust automation, fear of flood, so ASV is redundant in my case. After removal & a bit of replumbing due to the now absent ASV, I happily found a reduced pressure drop between source water input & RO membrane input (meaning more pressure present at RO input). This should make the membrane more efficient, or at the very least increase production rate of pure water. Difficult to tell for sure since product rate increase I've experienced isn't documented, but in the end, I'm glad to be rid of one more piece of finicky hardware.

01-27-2016, 04:21 AM
Hi Mike.
This is the one that I installed to replace the white straight through one...
http://www.purewaterproducts.com/products/rc301 (http://www.purewaterproducts.com/products/rc301)
It is classified as a U-type ASV.
For some reason it gives 6 psi more pressure to the holding tank, which works better for the ice maker.

Got a 50 gpd membrane coming for the holding tank in the fish room. But that room won't be free until my son moves out... again! :biggrin: