The Safety & Performance of your Printing Line: Basics of Flammability Measurement

For each flammable substance there is a level of concentration in air, usually expressed as a percent by volume, that is known as its Lower Flammable Limit, LFL, or Lower Explosive Limit, LEL. Below the LFL, the mixture of fuel and air is too lean to support combustion. For example, a mixture of 1.1 percent Hexane in air is equal to 100% of its LFL - just rich enough to propagate a flame.

The Safety & Performance of your Printing Line: Flammability Hazards

Industrial fires and explosions happen more frequently than most people think. They cause downtime, property damage, injury and sometimes death. These fires and explosions result from a dangerous mixture of flammable vapors with air and a source of ignition.

Process Ovens & Dryers in Real Life

For the past month we shined the spotlight on process ovens & dryers; we've looked at WHAT goes on in the application, WHICH hazards to avoid and WHY they should be monitored.

Money-Saving Steps in Process Ovens & Dryers

Controlling flammable vapors and installing solvent vapor monitors on your process oven and dryers allows the implementation of several money-saving steps:

Reducing Costs in Process Ovens & Dryers

Moving and heating large amounts of air can be extremely expensive. Many manufacturing processes must use chemical solvents in the production of their products. As a result, hot air dryers are frequently used as a means of evaporating those solvents.

Meeting NFPA Requirements in Ovens & Dryers

Almost all safety authorities require a 4:1 margin of safety below the LFL, based on worst-case conditions. This means that enough dilution air must be used to always maintain a concentration of less than 25% of the LFL, according to the National Fire Protection Association standard NFPA 86.

Key Hazards in Process Ovens & Dryers

Experience has shown that explosions in ovens and dryers can happen very quickly. The key hazard is an explosion from the build up of solvent vapors in the oven or dryer atmosphere. This buildup could occur by a malfunction in the production process such as:

  • a sudden or improper amount of coating 
  • a change in ventilation controls 
  • excessive speed

In any of these cases, the concentration of flammable vapor has an opportunity to rise above safe levels, creating a potentially explosive mixture of vapor in air.

Application Spotlight: Process Ovens & Dryers

Many industries involve coating products with a flammable solvent or mixture of solvents and then run through an oven or dryer to dry the solvents, so they are removed from the finished product. Examples of process ovens & dryers applications include:

Semiconductor Application in Real Life

For the past few weeks we shined the spotlight on the Semiconductor Application; we've looked at WHAT happens in a facility and WHY monitoring is necessary in the different parts of the facilities (PPM,

Area Monitoring of Storage Areas in Semiconductor Facilities

Hazardous gases are stored and distributed in the semiconductor plant, which includes:

  1. Storage Areas
  2. Distribution
  3. Delivery Piping

In these operations there exists the possibility that the hazardous gas could accidentally leak or spill into the surrounding area. Pumps, control valves, manifolds, piping junctions, fittings and connections are some of the potential sources for leaks or spills. With so many opportunities for leakage, continuous monitoring of such hazards is an essential part of keeping the plant safe.