Check valve on Suction side of Pump

Users who are viewing this thread

PlumblessInSeattle

New Member
Messages
4
Reaction score
1
Points
3
Location
Seattle
Qty 2 300 gallon water storage tanks serving the suction side of an above ground Jet pump. There is a check valve between the suction side of the pump and the storage tanks. I don't think the check valve should be there. The stored water is above the suction inlet side of the pump. Do you think the check valve in the attached photo is correct? If Yes, ease let us know why.
 

Attachments

  • 40701.jpeg
    40701.jpeg
    114.1 KB · Views: 421

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
I think there needs to be a check valve between the pressure tank and the storage tanks. I am not sure if it could be on the output side of the pump. I would think so.
 

Bannerman

Well-Known Member
Messages
4,795
Reaction score
768
Points
113
Location
Ontario, Canada
While the back pressure from the pressure tank will be stronger than the weight of the water above the check valve to ensure the check valve will fully close while the pump is not running, the check valve located directly at the inlet to the pump is likely to cause a cavitation situation within the pump.

The prescribed minimum length for a straight length of pipe before the pump inlet is 10X the diameter of the supply pipe so any item that will cause flow disturbance or turbulence such as an elbow, reducer, tee, valve etc will need to be located at a greater distance from the pump.
 
Last edited:

LLigetfa

DIYer, not in the trades
Messages
7,497
Reaction score
575
Points
113
Location
NW Ontario, Canada
While the back pressure from the pressure tank will be stronger than the weight of the water above the check valve to ensure the check valve will fully close while the pump is not running, the check valve located directly at the inlet to the pump is likely to cause a cavitation situation within the pump.
You are selling FUD. All jet pumps with a foot valve see the back pressure from the pressure tank plus the additional weight of the water column at .43 PSI per foot.

As for turbulence causing cavitation, that too is FUD. It may have some credence if drawing from max depth, but with the storage tanks providing positive head, it is a non-issue.
 

Valveman

Cary Austin
Staff member
Messages
14,599
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
While you should always have some straight pipe before the inlet of the pump, the check valve on the suction won't hurt anything on a small pump like that. The only problem I see is that there is no Cycle Stop Valve on the discharge of the pump and you wasted a lot of money on way too large a pressure tank. :)

 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks