Editing Vacuum ejector (section)

===Water aspirator===
The cheap and simple '''water aspirator''' is commonly used in [[chemistry]] and [[biology]] [[laboratories]] and consists of a tee fitting attached to a [[Tap (valve)|tap]] and has a [[Hose barb fitting|hose barb]] at one side. The flow of water passes through the straight portion of the tee, which has a restriction at the intersection, where the hose barb is attached. The vacuum hose should be connected to this barb. In the past, water aspirators were common for low-strength vacuums in chemistry benchwork. However, they are water-intensive, and depending on what the vacuum is being used for (e.g. solvent removal), they can violate environmental protection laws such as the [[Resource Conservation and Recovery Act of 1976|RCRA]] by mixing potentially hazardous chemicals into the water stream, then flushing them down a drain that often leads directly to the municipal sewer. Their use has decreased somewhat as small electric vacuum pumps are far more effective, environmentally safe, and have become more affordable, but the unmatched simplicity and reliability of this device have caused it to remain popular for small labs or as a backup.

Another, much larger version of this device is used in maritime operations as a device to dewater (drain) areas in a ship that have been flooded in emergency situations.  Typically referred to as an eductor in these applications, this is preferred over electrical pumps due to their simplicity, compact size, and greatly mitigated risk of explosion in the event that flammable liquids and/or vapors are present.  Additionally, unlike many mechanical pumps, they can also pass debris as the eductor has no moving parts that can be fouled.  This makes an eductor especially useful in situations where fitting a debris strainer to the suction port will present more issues than it resolves.  The size of the debris that can be passed depends on the physical size of the eductor.  Sizes, flow ratings, and applications vary, including eductors that are permanently installed (typically used in very large spaces, such as a ship's main engine room), or portable models that can be lowered into spaces by a rope and supplied and drained through firefighting hoses.  Most are supplied through a ship's firefighting main, and portable models can also be supplied by an emergency pump, provided it can supply sufficient flow to operate the eductor.