LEV Central

The Knowledge Base for LEV

Minor modifications: ITT – smoke test

Published on

This is a case study on the HSE website which looks into how minor modifications to an LEV Hood can make significant improvement to a tracer smoke assessment. ITT used booths to control exposure to harmful gases, mists and vapours emitted during cleaning of metal components. When smoke tests were used to check the effectiveness…

Local Exhaust Ventilation for the Control of Welding Fumes in the Construction Industry—A Literature Review

Published on

Abstract Arc welding is a common unit operation in the construction industry, where frequent changes in location and welding position make it more difficult to control fume exposures than in industries where fixed locations are the norm. Welders may be exposed to a variety of toxic airborne contaminants including manganese (Mn) and hexavalent chromium (CrVI)….

Process Guidance Note 6/02(12)

Published on

Process Guidance Note 6/02(12) Statutory guidance for the working of timber and manufacture of wood-based products.  September 2012. This is a document sourced in reply to a forum topic about Cyclones and Wood dust.  This explains the moisture content of typical wood dusts and when to apply and specify cyclones.


Published on

Radigan Engineering have a free to download excel spreadsheet. Taken from their website: When in the course of human events it becomes necessary to calculate the Darcy-Weisbach friction factor… engineer’s often throw up their hands, go back to their old college textbooks, and say “about .02!” [Which normally isn’t off by more than a factor…

Textile-based ductwork distribution systems

Published on

This module considers the design and application of textile-based air distribution systems which are sometimes used as an air input for LEV Systems. Taken from the article: Examples of the application of fabric- or textile-based air distribution stretch back into the mid-20th century, where simple, inflating cotton bags (or ‘socks’) were attached to the end…

Reference Material for The Safe Design of Perchloric Acid Fume Hood Exhaust Systems

Published on

This is a useful American PDF document, located on MK Plastics website dated 2008.  This references the best practices for the safe design of Perchloric Acid Fume Hood Exhaust Systems. Please make sure that you check that the resource meets the current guidelines of the country of where your design is to be applied.