WEF Discussions — Now on LinkedIn!

WEF is pleased to announce the creation of free LinkedIn groups associated with its technical discussion forum topics. Through these LinkedIn groups, members will be able to view and participate in discussions, as well as communicate with one another via direct messages. Share your experiences and knowledge, ask questions and respond to other discussions as frequently as you like!

You must have a LinkedIn profile to join a LinkedIn group; you can create your profile here. If you already have a LinkedIn profile, all you need to do is submit a request to join one or all of the following groups:

Water Environment Federation (Main) | Biosolids | Collection Systems | Nutrients | Stormwater 
Utility Management | Water Reuse | Water for Jobs | Watershed Management | Laboratory Practices 

RSS Feed Print
Primary clarifier chain
Posted: Tuesday, September 7, 2010 4:01 PM
Joined: 9/7/2010
Posts: 1


After making repairs to our plastic flights and plastic chain, we have had ongoing derailment issues.  I suspect that it may have to do with adding some (maybe 20 feet) of new chain with chain that may have been in service for ten years or more.  Does anyone have a rule of thumb when it comes to replacing some or all chain in a tank?


Thomas Jenkins
Posted: Thursday, September 9, 2010 8:01 AM
Joined: 1/13/2010
Posts: 8

I would guess that the issue is more one of chain tension than of mixing new and old chain. Both correct tension and even tension on both sides are important. If you put all of the new chain on one side then even tension may be a tough thing to accomplish.


Othere than as an emergency stop-gap I question the wisdom of partial replacement. It seems to me that if twenty feet of chain is worn the rest can't be far behind.

Posted: Tuesday, September 21, 2010 10:04 AM
Joined: 6/13/2010
Posts: 11

Plastic O.K. we also change as we notice wear and replace short sections at a time. Derailing caused by alignment in my opinion. Plumb bob used to check alignment. Also slack adjusters seizing could be a problem causing derailment. Replace friction bearings with sealed ball bearings.

Posted: Thursday, September 30, 2010 8:11 AM


Our tank was designed with wood flights and metal chain.  The tension on the system was primarily due to the weight of the flights and chain.  After changing to plastic flights and chain, we have little option for tension because the flights must sag under the baffles and weirs.  If the sag is removed, the flights would hit the baffle. 


Posted: Sunday, November 13, 2011 11:02 PM
Joined: 11/13/2011
Posts: 2

 They already have various men and women into their [url=http://www.asianescortscalgary.com]CalgaryEscort[/url] data base, this means you could find your responses thru these folks. When it isn'table, [url=http://www.asianescortscalgary.com] Calgary Escorts[/url] on the internet online networks tend to [url=http://www.asianescortscalgary.com]Calgary Asian Escort[/url] be an additional base free of [url=http://www.asianescortscalgary.com] Calgary Asian Escorts[/url] charge queries. Just for uncommon success, perhaps you may prefer to obtain the assistance of a smallbusiness what person bills an important price simply gain access to various other sources that individuals tend not to. Itrrrs likely, you'll see that significant other as a result of these techniques


Posted: Saturday, February 2, 2013 11:20 PM
Joined: 1/28/2013
Posts: 3

If you replace 10, 18, or 25 links on one side of the chain, then you need to replace exactly the same number on the opposite side in exactly the same location on both sides.


Chain stretches whether plastic or metal and if you don’t replace chain exactly in the same spot on both sides at the same time, you will have derailing problems.