Electric fuel "interupter" pumps on PA24

[Robert Wall]

Flow rate of Bendix electric pumps on 250 is supposed to be 32 gph into open line which figures out to 1:53 for one gallon.
My original (I think) Bendix pumps each need 2:15 to put out a gallon. Looking for new pumps -- Need a Facet part no. that is
the proper replacement pump and legal for certified airplane. Or do I need to replace pumps that are functioning well
except for slightly short flow rate? Aircraft Spruce lists several Facet pumps but no mention of PMA or sub for the Bendix.

[Clarence Beintema]

Robert,

If you look carefully at the pump mounting flange, you will usually find the part number stamped into the metal.

Clarence

[Robert Wall]

Thanks Clarence:

The pumps on the airplane are Bendix with a Bendix part no. Facet makes several models of interrupter pumps. I would like a Facet
part number to replace the Bendix pumps. Aircraft Spruce lists several Facet pumps no cross reference with Bendix, nor do they say
the Facet pumps are approved for a certified airplane. I have seen a Facet ad that indicates the pumps are for cars or tractors or ??.

[Zach Grant L1011jock]

I would not be too worried about the flow rate you mentioned. At that timing, each of your pumps are putting out close to 27 GPH. Each pump would be capable of running the maximum fuel flow of your engine independent of any other pump. The reason there are two pumps is simply that certification requires a 50% overcapacity from the maximum fuel flow of the engine. A 180 has a single pump with a maximum FF of 17 gph so is covered by a 32 gph pump. A 250 however requires a total backup capacity roughly 40 gph for cert. As you can see you are well within certification standards at 54gph combined.

-Zach