RO Flush Valve Hissing

TheEngineer · Feb 14, 2018

I just swapped out the flow restrictor on my RODI for a flush valve from BRS. It’s making a hissing sound. Is that normal? My last restrictor didn’t make a sound.

Idoc · Feb 14, 2018

My flush valve usually makes a little hissing noise when in use. Mine was leaking slightly, so just received a new one in the mail last night. Hopefully I have a chance tonight to install it... then I can see if it is also hissing

redfishbluefish · Feb 14, 2018

Might I assume it has the John Guest / Quick Connect fittings.....just make sure the tubing is square cut and is pushed in all the way.

KJAG · Feb 14, 2018

Are the ones from BRS Murlok valves? If not I’d recommend picking up those. Best thing I did to my spectrapure maxcap was replacing all the valves with Murlok fittings. * Edit I believe they are if you have the grey ones with green valve.

TheEngineer · Feb 14, 2018

Idoc said:
My flush valve usually makes a little hissing noise when in use. Mine was leaking slightly, so just received a new one in the mail last night. Hopefully I have a chance tonight to install it... then I can see if it is also hissing

Thanks!

redfishbluefish said:
Might I assume it has the John Guest / Quick Connect fittings.....just make sure the tubing is square cut and is pushed in all the way.

Yup! The connections look good. It sounds like it is coming from inside the valve itself. Just checked the ratios and I’m getting 3:1 (waste to product) so it seems to be working. Just loudly.

Shores805 said:
Are the ones from BRS Murlok valves? If not I’d recommend picking up those. Best thing I did to my spectrapure maxcap was replacing all the valves with Murlok fittings. * Edit I believe they are if you have the grey ones with green valve.

I’ll have to look that up. I’m not familiar.

K. Steven · Feb 14, 2018

My flush valve on my BRS RODI hisses when open and flushing the membrane, but no sound when closed and the water is forced through the flow restrictor during normal operation.

TheEngineer · Feb 14, 2018

K. Steven said:
My flush valve on my BRS RODI hisses when open and flushing the membrane, but no sound when closed and the water is forced through the flow restrictor during normal operation.

I was afraid of that.

TheEngineer · Feb 14, 2018

The connections are good. I’ll reach out to BRS and ask.

TheEngineer · Feb 14, 2018

Just talked to BRS. It's normal. Apparently if you run higher pressure it makes noise. I run at 85 PSI. Max for them is 90 PSI, I just found out. Good to know!

LPStandard · Feb 14, 2018

TheEngineer said:
Just talked to BRS. It's normal. Apparently if you run higher pressure it makes noise. I run at 85 PSI. Max for them is 90 PSI, I just found out. Good to know!

I was going to say, mine hisses when closed. I also run around 85psi. No leaks or other issues, and production is great.

K. Steven · Feb 14, 2018

Also run mine around 80-85 psi, no hissing sound. Only when open and flushing the membrane do I get the hissing.

Buckeye Hydro · Feb 14, 2018

No hissing at all: http://www.buckeyehydro.com/membrane-flush-kit/

rkpetersen · Feb 15, 2018

Sometimes I get noise from the BRS restrictor valve during operation, sometimes not. It's just turbulent flow as water goes through the restriction. There might be no sound with the pressure at a certain level, and then the sound/turbulence starts with corresponding increase in pressure by about 3-5 psi. Seems to be doing the job of maintaining the same pressure as the previous non-flushable flow restrictor, and my product water is pristine.

At first I didn't like the extra sound but now I love it because I'm reminded that the RODI is still running when I walk by the room; I don't forget to turn it off when the container is full nearly as often.

TheEngineer · Feb 15, 2018

My unit is in the basement, so I don't mind the sound. The RO membrane whines anyway

chicago · Mar 3, 2019

when my booster pump is on and the psi is 80 .. no hissing.. at 90 plus to 100 loud hissing. what I do get is the 1/4 line from the tap of the sink to the booster pump shaking like crazy..

iamahab · Dec 6, 2021

LPStandard said:
I was going to say, mine hisses when closed. I also run around 85psi. No leaks or other issues, and production is great.

I'm running mine at 70psi. Will it produce the ro water faster if I turn it up to 85?

Buckeye Hydro · Dec 13, 2021

iamahab said:
I'm running mine at 70psi. Will it produce the ro water faster if I turn it up to 85?

Yes - your membrane will produce water faster at higher pressures.

But be careful - your clear housings probably are not rated for 85 psi. If you are producing this pressure with a booster pump, make sure the pump is AFTER your prefilter housings.

You can plug in your water temperature and your water pressure into this calculator to see what your membrane will produce.

iamahab · Dec 13, 2021

Buckeye Hydro said:
Yes - your membrane will produce water faster at higher pressures.

But be careful - your clear housings probably are not rated for 85 psi. If you are producing this pressure with a booster pump, make sure the pump is AFTER your prefilter housings.

You can plug in your water temperature and your water pressure into this calculator to see what your membrane will produce.

Thanks