chilled water decoupler pipe connection

[moideen]

I saw a decoupled line bypassed secondary pump discharged to primary suction. Usually fitting of decoupler is the suction header of the primary-secondary pumps. But here connected to discharge header of secondary .what is the logic? Or is it a mistake?
thanks

 

[pocketengineer]

Could you post the schematic diagram? A picture speaks all.

 

[moideen]

this is the site image.and i got the drawing. but as per the drawing it is connectiod fron suction side of secondat. so i assume it was a big mistake on construction time

 

[pocketengineer]

The drawing is correct.

 

[pocketengineer]

just to add, the decoupler pipe hydraulically separates the 2 loops. The rate of flow in the primary loop must always equal or exceed the rate of flow in the secondary loop. The decoupler allows excess primary water to flow back to the return side of the chillers. If the decoupler pipe is connected to the discharge of the secondary pump, I don't see how it can achieve this task.

 

[moideen]

pocketengineer : you are absolutely correct.