These lines may be of a dual or single manifold design. In a single manifold design, the manifold's main purpose is for vacuum. Here is an example of a single manifold design which uses all-Teflon(tm) valves and O-ring joints to ensure a good vacuum seal. Each port has its own independent bubbler, so up to three reactions can be stirring under nitrogen at one time.
A dual manifold design provides one manifold for vacuum and another for nitrogen or a reactant gas. A connection between the two manifolds permits the nitrogen manifold to be easily evacuated.
Two features worth noting in this drawing are:
|Dual Manifold Line||Single Manifold Line||Dual Manifold,
|Single Bank Manifold||Double Bank Manifold||4-port Vacuum/Inert Line|
Keep your lab organized with PPE dispensers from Safety Emporium.
Laboratory Chemicals is a must-have reference for every research laboratory.
Always TRIPLE CHECK that the manifold and supply line are connected to pressure relief (and your pressure sensor) before opening the gas supply. ALWAYS use an appropriate pressure regulator to avoid opening the line to more than 1 atm of pressure at any time.
Should you lower the trap on your line and find a pale blue liquid, immediately replace the trap and back away. Consult your supervisor IMMEDIATELY. Warn others of the danger, posting signs if necessary.
In addition, the use of vacuum pumps also poses a hazard should flammable liquids become entrained in the pump oil. See Brown, K. J., Smith III, A. B., Nguyen, M. "Lessons Learned from Laboratory Vacuum Pump Exhaust Explosion: Discussion and Preventative Strategies" ACS Chem. Health Saf. 2022, 29(1), pp 87-90 for an example of an explosion inside a vacuum pump cabinet during a rotary evaporation.Disclaimer: This section discusses general dangers associated with high vacuum and Schlenk lines and is not meant to be a comprehensive reference to dealing with or assessing the hazards. There are many circumstances that have not been foreseen or discussed here and you should recognize the inherent danger in relying solely on this information!
The Schlenk Line Survival Guide by main group chemist Andryj Borys is a multipage resources with lots of nice pictures and examples.
This page was last updated Friday, December 2, 2022.
This document and associated figures* are copyright 1996-2023 by Rob Toreki. Send comments, kudos and suggestions to us via email.
*Some of these figures are adapted from the Chemglass, Inc. catalog and have been reproduced with permission.