×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Elevated Mg in a recirc loop post pump

Elevated Mg in a recirc loop post pump

Elevated Mg in a recirc loop post pump

(OP)
As part of our PW system, we have a break tank and recirc loop that we installed to isolate our pre-treatment zone from the the municipal mains. The wildly fluctuating pressure of the city water was playing havoc with our softeners mostly. The oddity we have been experiencing is elevated magnesium levels at a sample port just downstream of the booster pump for the recirc loop. This is a Grundfos SS unit, that at least from my research has nothing in it that might slough magnesium. Of course there may be some Mg getting by the softeners, and getting into the recirc system during times that water is just cycling through, but if that was the case, the elevated numbers would be throughout the loop I would think. Anyone ever experience a phenomenon like this?

RE: Elevated Mg in a recirc loop post pump

Do you have any equipment that may have been manufactured with anodes on to suppress galvanic corrosion?

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Elevated Mg in a recirc loop post pump

(OP)
Thanks for your reply. No nothing of the kind. In looking into the colorimetric method that we use to measure these values, I found that this test can be influenced by a number of different metals, including Cr. The pump having a number of 314L parts, might be giving up some chromium due to chlorine attack from the chlorine in the muni water. Our chlorine levels are low, but I suppose it's possible.  

RE: Elevated Mg in a recirc loop post pump

If you suspect that your pumps are releasing Cr, open it and make an internal checking. Also, what chlorine levels are we speaking about? I am not sure if the chlorine levels are sufficient to attack your pumps.
Or if you have a spare pump, replace it and check again for Mg problem.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources