Frequently asked questions

A lantern ring (also called a seal cage) is a perforated ring installed within a pump's packing set. It allows lubricant or flush fluid into the stuffing box, keeping packing lubricated, cool, and clear of abrasives.

PTFE Universal Lantern Ring is flexible lantern ring material that can be cut to length and installed in stuffing boxes where lubrication, cooling, or flushing is needed. It is designed to support packing performance and help reduce maintenance and downtime.

Lantern rings are commonly used in pumps and equipment where outside lubrication or flushing is needed to keep packing lubricated, cool, and clear of abrasives or chemicals. They may also be used in bearing assemblies as a conduit for grease or oil.

PTFE offers excellent chemical resistance, works across a wide pH range, and will not gall or score shafts or sleeves like some metallic rings can. PTFE Universal Lantern Ring material can also reduce inventory because one roll can be cut to fit different shaft sizes.

Cut to length on site with a knife or saw, then formed into a ring and placed between packing rows. Pliable enough to remove easily during repacking.

PTFE resists nearly all industrial chemicals across the full pH range. Known exceptions are molten alkali metals and elemental fluorine. Continuous use is rated to 500°F (260°C).

We work with distributors worldwide to supply end users, and directly with OEMs who use our PTFE lantern ring material as a raw material in their own products. End users can contact us for a distributor referral; distributors and OEMs can apply directly.

Flexfit Plastics PTFE Universal Lantern Ring material is made from 100% virgin PTFE.

The listed temperature capability is –240°C to 260°C / –400°F to 500°F.

The listed pH range is 0 to 14, making PTFE suitable for a wide range of fluids and applications.

PTFE material is non-metallic and will not gall or score shafts or sleeves, helping reduce the risk of stuffing box wear.

Flexfit Plastics offers stock sizes in both Standard Width and Extra Wide configurations. Available sizes include cross sections from 1/4 inch through 1 inch, with 48-inch lengths listed for stock material.
Metric sizes are also available.

Yes. Custom PTFE Universal Lantern Ring dimensions are available by request.

Choose the same “size” as the packing cross section required by the equipment. Then choose the width that best matches the original lantern ring. Additional widths may be created by combining PTFE flexible lantern ring material. Custom dimensions are available by request.

Yes. PTFE Universal Lantern Ring material is designed to be easily cut on the job site with a knife or saw, helping speed pump repacking and reduce downtime.

Yes. One of the key benefits of PTFE Universal Lantern Ring material is that one roll can be cut to length to fit any shaft size, helping reduce the need to stock many individual molded or machined lantern rings.

Yes. The material is flexible, durable, and designed for easy installation and removal.

Yes. PTFE Universal Lantern Ring material can replace many metal and plastic lantern rings, depending on the application requirements.

A lantern ring helps introduce lubrication or flushing into the stuffing box. This can keep packing cooler, lubricated, and clearer of abrasives or chemicals, which may extend packing life and reduce maintenance.

Yes. All Flexfit Plastics PTFE lantern ring material is proudly made in the USA.

Flexfit Plastics manufacturers and stocks all universal lantern ring material in Charlotte, North Carolina USA.

Yes. Flexfit Plastics offers fast worldwide shipping from stock manufactured in Charlotte, North Carolina USA.

Yes. Flexfit Plastics offers distributor pricing and is seeking distributors who share its commitment to quality, value, and customer service.

Complete the Distributor / OEM Application on the Flexfit Plastics website. A team member will follow up as soon as possible.