A matching bag size and micron grade do not establish ring or collar compatibility. The bag top must seat correctly in the particular housing and support basket. For a replacement order, use an approved drawing or sample that defines the sealing interface, rather than choosing from a photograph of a similar-looking ring.
This guide concerns the bag-to-housing interface. For bag body dimensions, start with the Size 1 vs Size 2 dimension guide; keep the collar specification as a separate acceptance item.
Representative liquid filter bags. The image is not a dimensional drawing or proof of compatibility with a particular collar seat.
Separate the bag top from the vessel closure gasket
The bag ring or molded collar locates the bag at its seat. The vessel lid gasket seals the pressure boundary. These components have different functions. A sound lid gasket does not prove that process liquid is passing through the bag media rather than around the bag top.
Likewise, changing a metal ring to a molded plastic collar is not simply a change in material. The profile, seating depth and retention arrangement can change. Confirm the complete combination before specifying PP filter bags or nylon mesh filter bags for an existing vessel.
What to measure and photograph
| RFQ detail | Record | Why it matters |
|---|---|---|
| Identification | Housing model, basket reference and current bag part number | Connects measurements to the correct equipment revision |
| Ring or collar geometry | Outside diameter, inside opening, height and section profile | A shared outside diameter alone can hide a different seating interface |
| Bag dimensions | Define the measurement datum and relaxed measurement condition | Overall length and usable bag length are not necessarily the same |
| Seat and restraint | Clear photographs of the empty seat, basket rim and retaining parts | Shows the mating features absent from a bag-only photograph |
| Materials | Bag top material, media and any separate sealing components | Compatibility must include every wetted component |
Use consistent units and identify each dimension on a sketch. Do not treat an inch designation and a rounded millimeter dimension as an exact tolerance. A used bag may be stretched, fouled or deformed; flag it as used and compare it with an unused retained sample if available.
A safe sample-approval sequence
Have qualified personnel isolate, depressurize, drain and make the equipment safe under the housing instructions before inspecting internal parts. This article is not an operating or lockout procedure. Never open a pressurized vessel or alter a retaining component to force a replacement to fit.
- Agree a drawing revision and identify the dimensions critical to seating.
- Request a representative sample with its material and construction identified.
- Check installation, basket support and closure using the equipment manufacturer’s instructions.
- Run an approved process trial and assess downstream cleanliness as well as flow behavior.
- Record the accepted sample, drawing and purchasing part code together.
Eaton’s SENTINEL documentation, for example, describes a product-specific sealing ring and recommends correct bag alignment within the restrainer basket. This supports checking the assembly, not assuming that every similarly sized ring is interchangeable. It does not establish that an INCE replacement uses Eaton’s proprietary seal or has its performance claims.
Fit remains separate from the filtration grade
A 75 micron or 250 micron bag still needs a matching collar and basket, regardless of the media selected. Conversely, a collar that seats properly does not verify particle retention. Keep media construction, rating basis and required process result on the specification alongside the mechanical interface.
For single bag housings, reference the actual installed basket. For multi bag housings, confirm the seat and basket arrangement for every position and record any equipment variation. Do not infer interchangeability from bag count.
Request a replacement fit review
Send the housing and basket references, bag-top sketch, seat photographs, current bag code, media, micron grade and order quantity. Ask for proposed dimensions, tolerances and sample approval before bulk manufacture. Do not include confidential process information unless needed for the review.
Frequently asked questions
Can I order by ring outside diameter alone?
No. Include the collar section, height, seat and restraint arrangement, bag dimensions and equipment reference. The same outside diameter can occur with different mating profiles.
Does a Size 2 label guarantee that the collar fits?
No. A size designation is not a complete interface specification. Confirm the ring or collar geometry and actual housing basket.
What if no original drawing is available?
Provide clear seat and bag-top photographs, a dimensioned sketch and an identified sample. Treat the proposed replacement as requiring sample and process approval rather than as a confirmed interchange.
Technical reference
Eaton SENTINEL product documentation — assembly and installation example only; no transfer of its branded performance claims to INCE products.
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