FSI Felt Bags are the Answer

When it comes to felt filter bags, FSI has the answer. Our years of experience give us an advantage over our competitors, and our felt filter bags show it. Our felt bags are designed to withstand higher solid loading, and are suitable for applications using vessel or open filtration systems. FSI’s “Comprehensive Manufacturing Control”philosophy insures that we will maintain our status as the industry leader in all phases of the filter business.

Our integrated technology and superior control over our manufacturing and quality leads to consistent performance. With FSI filter bags, you can count on what you are getting.

We start with the finest material possible. FSI produces the felt material used in our felt filter bags in house, guaranteeing the highest quality. Our Extended Life filter bag provides superior filtration of all sized particles over traditional filter bags, as well as up to twice the dirt holding capacity of a standard filter bag.

Our no-bypass welded seams eliminate the possibility of fluid bypass through needle holes. We provide a variety of glazed and singed finishes to inhibit fiber migration. FSI also offers polypropylene and polyester inserted felts. These inserted felts include a reinforcing scrim needled inside the felt material, to provide added strength and durability.


• We offer a full line of felt materials and micron ratings.

• Conventional sewn bags or the PolyWeld® welded seam bags available.

• Conventional bag rings or the FSI Polyloc® ring available on most bags.

• Heavy Duty and Extended Life designs available to suit your filtration needs.

Providing Consistent Performance

The FSI PONG filter bag is one of the most versatile and popular bags on the market. Made from a noninserted polypropylene felt with a glazed surface finish, the standard bag incorporates the PolyWeld® welded seam design. The Polyloc® ring provides hermetic sealing, preventing steel ring bypass problems.

And the welded seam eliminates unfiltered liquid bypass occurring due to needle holes. The PENG filter bag is made from non-inserted polyester, and can be ordered with the polyester Polyloc ring. These bags come in a variety of sizes and ring seals to suit your vessel requirements.