Abstract: A seal section for use in a downhole submersible pumping system includes a modular seal bag assembly having a first end cap, a second end cap and a plurality of seal bags connected between the first and second end caps. Each of the first and second end caps includes a plurality of nozzles and each of the plurality of seal bags is connected to a unique pair of nozzles on the first and second end caps. The modular seal bag assembly further includes a shaft tube connected between the first and second end caps. In a second preferred embodiment, the present invention provides a seal section that includes a single seal bag connected between two opposing end caps. The seal bag is preferably seamless and fabricated from a fluoropolymer, such as perfluoroalkoxy (PFA).