Pump/piping question
Pump/piping question
(OP)
I have two pumps operating in separate sumps and joining at tee and entering a tank through a single line. All lines are 2" O.D. HDPE SDR 11 pipe, shortly after the connection, the line enters a manhole and exits as a 4" SDR 11 HDPE Pipe. I have very little info on the pumps other than one was spec'ed at 55 GPM at 96' TDH and the other at 53 GPM at 85' TDH. I need to ensure this configuration is not a problem, especially in the 2" line before it expands to 4". Any insight on how to best check this? Thanks.





RE: Pump/piping question
RE: Pump/piping question
When the combined flow enters a manhole, does the pressure go to atmospheric? That is not clear in your post. Is the manhole before or after the tank connection? A sketch would help.
RE: Pump/piping question
2-inch (nominal) HDPE has an OD of 2.375 inches. So SDR 11 would be 9/11ths of that or 1.94 inches. Someone may make a 2-inch OD HDPE, but I've never seen it in the catalogs.
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: Pump/piping question
ID = OD [1-2.12/DR]
While it is a fine point particularly in this case, applying this recommendation to the current example and assuming the OD is in fact 2.375" (not the 2" of the OP) and the DR is "11", the ID so-calculated however would be:
ID2 = 2.375 in [1 - 2.12/11] = 1.917 in
RE: Pump/piping question
ID=OD-2t --> ID = OD - 2(OD/SDR) --> ID = OD*(1-2/SDR) --> ID = OD*(SDR-2)/SDR
Not a "rule of thumb" at all, just arithmetic.
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: Pump/piping question
RE: Pump/piping question