The hidden costs of water aspirators

Vacuum pump supplier JAVAC has delivered some words of wisdom surrounding the use of water aspirators — a common way to create a low-strength vacuum in many standard laboratory applications.

The simple design of a water aspirator utilises water running through a narrowing tube to create a reduced pressure via a venturi effect. The performance of the pump is dependent on the temperature, resulting in an unreliable vacuum source. Also, when used in chemistry and biology labs, aspirators (venturi pumps) allow potentially hazardous solvents to mix in to the water stream and flow down the drain. A significant amount of water is wasted because a stream of continuously running water is required to operate the pump.

So even though the upfront purchase price and ease of use of venturi pumps may make it appear to be an attractive option for low-vacuum applications, JAVAC warns that the hidden costs of ownership are prominent. With increasing water prices, limitations on water usage and tightening environmental protections, water jet pumps become more of a liability than an asset. Simplicity and low cost becomes restrictive and expensive to operate, according to the company.

JAVAC suggests that other pump technologies are better suited to providing a consistent vacuum performance which adheres to the increasing environmental initiatives. Alternatives such as dry-diaphragm pumps offer deeper end vacuum capabilities, higher flow rates and minimal operating costs. The company claims that the cost incurred to replace a water aspirator by purchasing an oil-free diaphragm pump will offset the upfront power costs in no time, often leading to payback within a year.