BOLA flip page catalog
BOLA flip page catalog


What you should know about BOLA Stopcock-Plugs

  • BOLA Stopcock-Plugs are exclusively made of virgin PTFE. They are produced according to state-of-the-art technology.
  • All BOLA Stopcock-Plugs are made of FDA-conform PTFE. A corresponding certificate of conformance is included in each shipment.
  • PTFE is extremely sturdy, durable and resistant to high temperatures.It virtually does not absorb humidity and does not brittleeven at temperatures below 0 °C.
  • The taper of BOLA Stopcock-Plugs is manufactured precisely (max. deviation +5 μm) and matches ideally polished glass casings.
  • The sealing surface of BOLA Stopcock-Plugs is finished in a special procedure. It is extremely smooth and provides excellent sealing on all glass surfaces.
  • BOLA Stopcock-Plugs are manufactured according to DIN 12 540 and can be used with any polished glass casings (readily identifiable by their clear and transparent surface).
What you should know about BOLA Stopcock-Plugs


First, take the stopcock-plug out of the glass casing. For this, loose the nut, remove the washer and, if applicable, the O-ring. Please ensure not to lose one of the single components. Rinse the plug as well as its casing with acetone. Once all components are dried, the stopcock plug can be assembled again. Do not use any abrasive cleaning agents as they might damage the sealing surfaces of the stopcock plug and the glass casing.

Security Advice

Although providing a very good chemical resistance, PTFE stopcock plugs combined with glass vessels are not recommended for long term storage of products that attack glass. The surface of the glass casing might get damaged. The possible leakage of the stopcock is a potential security risk. After being used with such caustic products, the PTFE plugs have to be carefully rinsed with water before re-use. This helps also to remove deposits or efflorescence products especially in the bores. Such residues can damage the sealing surface of the plug when turning it and thus cause leakage. The material PTFE is softer than glass. That is why PTFE plugs tend to adapt their form to the glass casing and to extend to the glasstube ends. Such distortion can affect the tightness. Therefore please loose the plug inside the glass casing after use and store the cleaned components in dust-free atmosphere until you need them again.

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