Recent content by Nicksun

In my application, we put pressure retaining valve with minor back pressure on the bottom of overflow pipe. This is constructed but not running yet.

air stripping first, then oxidation or bio treatment. but someone may help with more detail, like when to use stripping, when to use bio, and when to oxidize..

who is the vendor of this B'fly vlv? Armri from KSB? Heard about it but never use this. But we use a lot Gemue b'fly vlv. Good quality.

Buna-N gasket is fragile to oxidant, I think. EPDM is somewhat a standard for various applications because it is cheap and commonplace and good mech/chemical property. see the attached for an overview of gasket material...

I think you are not posting the right question here. The core problem is how to design a supply loop to meet POUs pressure and consumption requirements? Is this right? If yes, you need to take account into all the ideas expressed as above: 1 - What is the minimum flow required by the pump...

Thanks for all the inputs. To bimr: The UPW system is new, started running in 2005 and has run well. the MB resin can not separate well, becuase the inlet water is 1Mohm.cm and the setpoint of MB exhaust is according to 50pppt boron. so the H and OH resin still alive and attract each other...

Thanks S.Bush for the insights. Becuase the high-purity NaCl not readily available. Now I have killed the mixed bed resin with 55g 100%NaOH/L (anion resin).After this, displace and rinse the bed. And the separation was very successful. After double regen, the rinsing water resisitivity is...

Dear All, I got a UPW plant:MMF->ACF->cat-anion->RO->MB->Polishing. Now the MB resin can not separate well, becuase the inlet water is 1Mohm.cm and the setpoint of MB exhaust is according to 50pppt boron. so the H and OH resin still alive and absorb each other. After discuss, we use NaOH to...

Yes, it is right. Due to different regeneration level, the top level is 7cm than the original level. Nick

Thanks for bimr's insights. Next Monday, another regeneration will be made. at that time, if the top level keeps the same with last one, we can tell it is due to regeneration level problem. if the level goes down again, which i don't want to see, the resin is lost due to some reason. Ok, i...

To me, once the valve is open, it opened to its setup open degree. So the problem is not the valve itself if it is able to open. So the flowrate is low, it should be wrong with the feeding pump like BIMR comments. Please check the overall pressure profile of your system.

Hi,bimr, Based on your advice - swelling/shrinking concept, i would like to guess: when resin is new, it is totally swellen for SAC/SBA resin. When the new resin is exhausted, it got shrinken for SAC/SBA resin which is about 8% and 20% less for SAC and SBA respectively. But when it is...

Dear All, we have one UPW plant in starting up. one problem occurs: the regen WW from cation bed / anion bed get a layer of bubble which malfunction our ultrasonic level sensor. so what causes these bubbles/foaming?? thanks, nick

Dear All, i had made a MB internal repair for one client, and then loaded with new MB resin(R&H 1400H/4000OH). and i loaded till resin level reached the middle of middle sight glass. but after the first regeneration, the top level is 7 cm lower??!! the first reaction is resin is leaking from...

Dear Gacguy, Thank you very much for your thoughtful input. Is it possible that the dosage of NaClO reduced the hardness of activated carbon? If so, this possibly can explain why caron running out after a month's operation. i would like to rethink the design paramenters. thank you. Nicksun