GPM Capacity of 2" Shower Drain
Greetings gang and thanks in advance for any help:
we are remodelling our shower and are looking to put in multiple shower heads and some body sprays.
our current drain is 2".
My question is what is the maximum GPM flow that this drain will handle? Also, is there somewhere on line where I can look at the calculations, etc?
Thanks again for any help.
Flow Rates of a 2" Shower Drain
I found this old post and thought I could add in my own two bits.
I have done a load of private testing on the subject of flow testing and have found many of these 2" drains can handle easily between 8-16 GPM (Gallons Per Minute). In my tests most drains see no build up of water (above grate) at 8-10 GPM or less. When the flow rates creep up higher so does the water level above the grate.
At 18 GPM I have measure 3/8" of water above the drains grate.
We have also noticed that flow rates drop when the drop to the P-Trp is not vertical. We also noticed that the higher the drop the better the flow rate. We have also noticed that any mis installed fitting can greatly lower the flow rates.
Hope this helps.
Originally Posted by GAtkins