Filter Bag FAQ
What’s the difference between a size 1 and size 2 filter bag?
Same 7″ ring, different length: size 1 is 16.5″ long (2 ft² of media), size 2 is 32″ (4.4 ft²). They are not interchangeable — the bag must match the housing basket length.
When should I change a filter bag?
At about 15 PSID differential pressure across the housing, or on a time schedule if you don’t have gauges. Running far past 15 PSID risks rupture and particle unloading through the media.
Sewn or welded — which do I need?
Sewn costs less and suits most applications. Welded eliminates needle-hole bypass and thread, and is silicone-free — choose it for paints, coatings, inks, and any process where trace bypass or silicone contamination is a defect. More on welded bags.
What does the micron rating mean?
For felt bags it’s a nominal rating (majority capture at that size, improving as cake builds). Monofilament mesh is a true geometric cutoff. Full explanation here.
Can filter bags be washed and reused?
Mesh bags, yes — wash out the cake and return to service. Felt bags are depth media; washing removes surface cake but not embedded solids, so reuse is limited and not recommended for critical service.
Which ring material should I pick?
Galvanized steel is standard and cheapest. Stainless for corrosives and food service. Polypropylene or nylon when metal contact is prohibited or the ring must survive aggressive chemistry — and plastic rings are fully incinerable with the bag.
What temperature can the bags handle?
Polypropylene to ~200°F, polyester to ~275°F, Nomex to ~450°F. Above that, talk to us about specialty media.
Do you make FDA-compliant bags?
Yes — FDA-grade polyester, polypropylene, and mesh with vendor certificates of conformance on file. Specify FDA grade when quoting.
Can you match a competitor’s part number?
Almost always. Eaton, Rosedale, FSI/Pall, Strainrite, Parker, Hayward, GAF and others follow decodable conventions — send the number through the quote form and we’ll cross it to our equivalent.
What’s your minimum order?
Small. We’re a manufacturer that welcomes short runs — including one-off custom bags. Ask.