Boiler feed pumps options

londonrefrig

Need help figuring pumps. My pump guys seem to be struggling on this one.

I have two steam boilers (burnham 5007 and 5010) feed with two pumps from one 30gal condensate receiver. Receiver is leaking and customer has had another one built.... pumps seem oversized (be-s50).

From what i can gather, boilers loose .77gpm and 1.16gpm respectively. System pressure is under 2 psi. Allowing for sys pressure plus 5psi for discharge psi, thinking 7 psi pump pressure. My pump flow should be 1.5-3x losses. So 1.2-3gpm.

How would the experienced guys here do this?

Is there pumps that will run those specs that arent $1000s?

I know grundfos and others have heating circulators that run that low, but they arent recommended, why?

Thanks in advance.

Mad Dog_2

What I recommend you do is reach out to Taco Of Cranston Rhode Island. They monitor The Wall. They will be glad to help you with this. Taco is still a Family Owned, American company...great folks to deal with. Mad Dog

clammy

there are no cheap pumps . They are specifically designed for the purpose to handle high temp and a low nspt . A standard circ designed for a closed hydronic system will not work either its net suction inlet pressure would not be enough for it to operate properly and the possible high temp and debrie may damage the impeller.

There is a reason why they cost so much being that is there designed function .

Trying not to be negative but it seems condensate /boiler feed pump and traps and vents are the one thing nobody wants to replace only as a last resort .Its kinda like going to a dinner party and everybody gets up to use the can and your left paying the bill . It is what it is and ya pay for what ya pay thats all there is to it . I sometimes feel that when faced w these type of service calls repairs that i would stand a better chance at there first born then having them do any work in respect to steam systems in large apartment building or homes they seems to go for the quick fix rig rather then squaring things away properly . . Quite funny .

peace and good luck clammy

Mad Dog_2

LIsten to The Clam.....he knows...Mad Dog

retiredguy

The quick and cheap fix would be to install a square head plug cock in each pumps discharge line to throttle the pumps flow to what is necessary for each boiler. If these were large boilers there are a few better but more expensive ways to control the pumps flow. This will get you "out of the woods" as we say in my area.

EBEBRATT-Ed

I don't think Taco make boiler feed or condensate pumps. Bell & Gossett (Hoffman), Shipco, Mepco and Skidmore and there are others.

For low pressure steam I used to size them at double the boiler(s) evaporation rate and 20psi.

Others use different sizing methods

Pumpguy

Agree with @EBEBRATT-Ed. For a boiler feed unit, first step is to size the storage tank. I like to size for a 20 minute storage capacity.

Next, size for GPM flow capacity. This depends on the steaming capacity of the boiler. This can be determined with any of the following: Boiler Horsepower, Square Feet EDR, lbs/hr of steam produced, MBH (1000 BTUh), or Kilowatts (kW).

And finally, the operating pressure of the boiler and any pipe friction losses between the pump discharge and the boiler.

Mad Dog_2

Ttraditionally no, but in the last few years Taco has expanded in to adjacent pump markets. I would be surprised if they are involved here too. Mad Dog

Joe Mattiello

steam boiler condensate pumping is considered an open to atmosphere system which requires a low NPSH pump. I saw one comment, suggestion about plugging discharge port. To understand, that’s to slow down the pump hydraulic displacement essentially correcting the npsh curve.

Placement of the pump, and minimizing suction line length, and increasing diameter of suction line are great ways to allow enough flow to satisfy pump NPSHR.
I suggest reaching out to those anxious to help Tech support technicians at Taco. Tech support phone number is 401-942-8000

I’m sure they’ll be able to help with this. You don’t need to spend a lot of money, just spending your money wisely works:-)