VEE GEE 6168-4751 is the replacement No. 8 silicone stopper for SIBATA 6168 series filter systems, sold individually. The perforated stopper seats into the sidearm of a standard 1000 mL filtering flask, connecting the filter base assembly to the vacuum source for vacuum-assisted membrane filtration. Included in all four complete 6168 filter kits — the 6168-4751 is the standalone replacement for labs that need to replace a torn, deformed, or missing stopper without purchasing a full new kit. Autoclavable at 121°C. Compatible with all 6168 series kit configurations (fritted glass and SS screen, 100 mL and 300 mL).
Features & Benefits
- No. 8 Size — Fits Standard 1000 mL Filter Flask Sidearm: The No. 8 stopper is sized to fit the sidearm of a standard 1000 mL borosilicate glass filtering flask — the most common flask size used in 47 mm membrane filtration setups. The stopper is perforated to allow the vacuum line to pass through while sealing the flask neck.
- Silicone Construction — Flexible and Durable: Silicone provides a flexible, compressible seal that conforms to the flask sidearm and maintains vacuum integrity under the pressures used in membrane filtration. Silicone is resistant to sterilization temperatures and is compatible with aqueous and mild solvent filtrate systems.
- Autoclavable at 121°C: Silicone retains its physical properties through repeated autoclaving at 121°C (250°F) — sterilize with the rest of the filter assembly between biological samples.
- Universal Across All 6168 Series Kits: The same 6168-4751 stopper is used in all four complete kit configurations — 6168-0001, 6168-0002, 6168-0003, and 6168-0004. One stopper SKU covers the entire 6168 series.
- 1-Year Warranty: Backed by VEE GEE Scientific's standard accessory warranty.
Specifications
| Property | Value |
|---|---|
| SKU | 6168-4751 |
| Description | No. 8 Silicone Stopper (perforated) |
| Material | Silicone |
| Stopper Size | No. 8 — fits standard 1000 mL filter flask sidearm |
| Autoclavable | Yes — 121°C (250°F) |
| Used In All Kits | 6168-0001, 6168-0002, 6168-0003, 6168-0004 |
| Dimensions (L × W × H) | 1.5" × 1.5" × 1.0" (3.8 × 3.8 × 2.5 cm) |
| Quantity | 1 Each |
| Country of Origin | Taiwan |
| Manufacturer | SIBATA Scientific Technology Ltd. |
| Brand | VEE GEE Scientific |
| Warranty | 1 Year |
6168 Series Complete Component Reference
| SKU | Description | Type |
|---|---|---|
| 6168-0001 | Fritted Glass Filter System, 300 mL — Complete Kit | Complete kit |
| 6168-0002 | SS Screen Filter System, 300 mL — Complete Kit | Complete kit |
| 6168-0003 | Fritted Glass Filter System, 100 mL — Complete Kit | Complete kit |
| 6168-0004 | SS Screen Filter System, 100 mL — Complete Kit | Complete kit |
| 6168-47100 | Replacement 100 mL Funnel | Replacement part |
| 6168-4711 | Replacement 300 mL Funnel | Replacement part |
| 6168-4721 | Glass Support Base, for SS Screen | Replacement part |
| 6168-4722 | Fritted Glass Support Base | Replacement part |
| 6168-4731 | Stainless Steel Screen | Replacement part |
| 6168-4741 | PTFE Gasket — Pack of 10 | Replacement part |
| 6168-4751 (this item) | No. 8 Silicone Stopper | Replacement part |
| 6168-4762 | Anodized Aluminum Clamp, 47 mm I.D. | Replacement part |
Frequently Asked Questions
Does this stopper fit a 500 mL or 2000 mL filter flask, or only 1000 mL?
The No. 8 stopper is sized for the standard 1000 mL filtering flask sidearm — this is the most common flask used with 47 mm filtration systems and the flask size the 6168 series kits are designed for. Flask sidearm diameters can vary by manufacturer. While many 500 mL and 2000 mL flasks also use a No. 8 sidearm stopper, verify the sidearm diameter of your specific flask before ordering. If your flask sidearm is a different size, a standard rubber or silicone stopper in the appropriate number can be used as an alternative.
Is the stopper the same for all four 6168 kit configurations?
Yes. The 6168-4751 No. 8 silicone stopper is used identically in all four 6168 complete kit configurations — the fritted glass and SS screen kits in both 100 mL and 300 mL funnel sizes. The stopper connects the filter base to the vacuum flask and is independent of the filter support base or funnel size.
How do I know when to replace the silicone stopper?
Replace the stopper if it no longer holds vacuum (the system slowly loses suction during filtration), if the silicone is visibly cracked, torn, or hardened, or if it has been exposed to solvents that degrade silicone (certain organic solvents can swell or soften silicone over time). For aggressive solvent applications, a PTFE-coated stopper or all-PTFE stopper may be a better long-term choice — though the standard silicone stopper is suitable for aqueous and most standard lab filtration applications.
Ordering
Authorized dealer, ships from USA inventory. Serving academic, government, and research laboratories nationwide.