Fulflo natural polypropylene vessels for high purity applications. Parker’s Fulflo NP series vessels feature pure natural polypropylene construction. The NP series is an ideal economical alternative to stainless steel and fluoropolymer vessels for filtration of corrosive fluids. They are essential for applications and processes demanding high purity filtration. Availability of 10 inch and 20 inch lengths and both single and double-open-end seal designs adds additional versatility.