Pump Suction Inlet Bell

The suction bell on a vertical pump ensures smooth entry of water to impeller.

In an horizontal pump a eccentric reducer (flat part on top) is preferred. (High point in a suction will gather air).

I have a vertical suction pipe down into a pit and the bell is wanted for the end of this pipe. Sorry I wasn't more clear.

Does it have to be cast iron? If so look at the casting you have for the name of the foundry that made the cast iron one you have. If the name is not there look for letters or symbols they do mark their products. Call them.

Welding shops do made special orders from steel.

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You can put a 16" ANSI flange on the end of the pipe and bolt a 16" cast iron pump suction bell to it. That said, not really necessary. HI makes that recommendation based on the distance from the tip to the eye of the impeller. Encourages laminar flow. Based on the length of suction pipe, a bell would not have an impact. More important is conditions of the sump around the suction pipe.

Joe T.

Thanks for your comments. The inlet bell does two important things, both related to the system inlet velocity. It has a very low loss coefficient compared to a Borda inlet and with reduced inlet velocity it removes over 95% of the suction inlet loss. It also lowers the Froude Number and reduces inlet vortex potential. These are the reasons I want it, it reduces pump TDH and it allows a lower submergence, if required in an emergency. I guess there is no shops out there called the "inlet bell guys". I do have a pump inlet casting plan in mind. I am surprised this fitting is not more common.

While I'm not sure exactly what you are referring to as an "inlet bell", I believe a F&D 125# ductile iron flanged-flare fitting(s) will probably mate with your 16" "150#" connection. There are perhaps mulitple vendors for such (including e.g. http://www.acipco.com/adip/specials/flare.cfm ).

Randy, thank you very much. This fitting is ideal. The term Inlet Bell is used by the Hydraulics Institute (HI) so I did too. The straight version is exactly what I was looking for. This blog has my attention from now on and I hope I can assist someone as you have helped me.

Ron Parriott

I believe "Crane Valves" a company in King of Prussia, PA, may be able to supply you with a bell housing for your pump.

vshwn7@aol.com

hi man, im really happy if could see u answerin this question.... will a belled suction inlet improve the efficiency of the multisatage mixed flow submersible pump...? what are the other parameters one needs to change to improve the efficeiency of the mixed flow pump?

regards,

nag