CUSTOM ITEM: Caps, Screw Top, with Silicone Rubber / PTFE Pre-Slit Septa, bonded in "knurled", polypropylene, White Caps. For use with 13-425mm thread, 15x45mm autosampler vials. MICROSOLV Brand. BULK PRICING.

Additional Info:

Pre‑slit septa reduce resistance during autosampler needle entry, supporting smoother injections in systems where penetration force is a concern.

The 9504S‑30C‑W screw caps feature bonded silicone/PTFE pre‑slit septa that improve penetration performance while preventing “septa plunge” into vials during injection. The bonded design keeps the septa securely in place, reducing the risk of dislodging during transport or repeated use. These caps are commonly used with older Waters® autosamplers that utilize 15 × 45 mm (4 mL) vial formats.

The silicone/PTFE construction provides chemical resistance and reliable sealing for HPLC, GC, and LC‑MS workflows. The white polypropylene cap includes a knurled exterior for secure handling and consistent torque when sealing standard 13‑425 autosampler vials.


Key Features & Benefits

  • Pre‑slit septa ✅ Easier needle penetration

  • Bonded septa design ✅ Prevents septa plunge and dislodging

  • Silicone/PTFE construction ✅ Chemical resistance and sealing performance

  • Fits 15 × 45 mm (4 mL) autosampler vials ✅ Standard 13‑425 compatibility

  • White knurled cap ✅ Secure handling and clean appearance


Typical Applications

  • HPLC and UHPLC analysis

  • LC‑MS and GC‑MS workflows

  • Older Waters® autosampler systems

  • Higher volume vial applications


Important Notes

  • For 13‑425, 15 × 45 mm (4 mL) autosampler vials only

  • Suitable for multiple injections

  • Bonded pre‑slit septa—no assembly required

  • Designed for legacy autosampler compatibility

  • This and other custom items are Custom Ordered and require quotation


Additional Resources


Custom Item Pricing Information

Custom Order Item. Inquire for more information.

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