Polyurethane Foam Stopper / Lid for Cryogenic Liquid Nitrogen Storage Tanks (35 mm – 125 mm Neck)

Cryogenic lab consumable · LN2 tank spare · Polyurethane foam lid

A direct replacement lid / stopper for laboratory and industrial cryogenic storage vessels holding liquid nitrogen (LN2). The closed-cell polyurethane foam body provides a low thermal-conductivity barrier that limits boil-off when the neck is sealed between sample retrievals, while the ribbed outer profile and tapered plug geometry press-fit into neck openings from 35 mm to 125 mm. Suitable for IVF / stem-cell / biobank storage, semen banks, pharmaceutical cold-chain sampling, university life-science labs, and on-site process-cooling reservoirs tied to a factory automation temperature monitoring loop.

Key Specifications

Datasheet Highlights

• Closed-cell PU foam resists moisture ingress, vapour diffusion, and microbial growth during routine use
• Tapered plug & stepped-rib profile self-centres inside the neck and stays seated when the dewar is moved
• Operates continuously at −196 °C without cracking or hardening — verified by thermal-cycle soak testing
• Replaces worn or lost original OEM stoppers on common 3 L / 6 L / 10 L / 25 L / 35 L / 50 L lab dewars
• Single-piece moulding — no separate gaskets, O-rings, or fasteners required
• Non-marking top handle tab allows tool-free removal with cryo gloves
• Hydrophobic foam matrix sheds surface condensation, reducing frost-ice build-up on the neck rim
• Compatible with routine dewar cleaning protocols using isopropyl alcohol or mild laboratory disinfectant wipes

Typical Applications

• IVF clinics, reproductive-medicine labs, andrology / andrology cryo banks
• Stem-cell, cord-blood, and biobank storage (GMP / ISO 20387 facilities)
• Pharmaceutical cold-chain sampling, vaccine / biologic retention samples
• University life-science and biochemistry research labs
• Veterinary AI (artificial-insemination) semen storage
• Industrial cryo-process reservoirs (cold-trap, vacuum-pump LN2 feed, sample freeze-quench stations)
• Process-cooling LN2 buffer tanks tied to factory-automation temperature monitoring loops
• Replacement lid for worn or lost original stoppers on MVE / Chart / Taylor-Wharton / CBS / Worthington Industries style lab dewars
• Field-service kit for cryo-vacuum pump inlet traps on semiconductor inspection or analytical instrument bays
• Cryo-grinding and freeze-fracture sample preparation in materials-testing labs

A single damaged or missing stopper will accelerate LN2 boil-off and shorten the interval between refills, which in a 24/7 IVF workflow or continuous cryo-cooling loop translates directly into unscheduled downtime. KOEED carries this replacement as a stocking consumable so that maintenance teams and lab facilities do not have to order an entire new dewar to recover a working neck seal. When the existing stopper has cracked, absorbed LN2 and become brittle, or fallen behind a freezer cabinet and been lost, this part returns the dewar to its as-shipped thermal performance.

Related Modules & Cross-Reference

Warranty & Authenticity

Each stopper is inspected for dimensional conformity (35–125 mm neck range), surface finish, and thermal-cycle integrity before shipment. KOEED ships worldwide via DHL / FedEx with a 90-day limited warranty against manufacturing defects. For multi-unit or facility-level stocking, send a count by neck diameter to Moritta@KOEED.COM and we will return a quotation within 24 hours on business days. Cryo-handling best practice recommends keeping at least one spare stopper per dewar size in inventory so a damaged or lost lid does not interrupt sample storage or process cooling. For large or multi-site cryo facilities we can also prepare a master pack covering the most common 35, 50, 80, 100, and 125 mm neck sizes to standardise spares handling across the lab.