Choosing the right Explosion-Proof Vacuum
How do I choose the right explosion-proof vacuum, grounded vacuum or anti-static vacuum?
Keeping your facility free of combustible dust is much easier said than done. Traditional plant maintenance methods like sweeping and blowing down with compressed air only make the situation worse by spreading the combustible dust around and making it airborne. This actually increases your chances of a combustible dust explosion.
That’s why specialized industrial vacuums are now generally accepted as the best way to combat combustible dust and other explosive materials. However, in many cases these vacuums – with electric motors and metal parts – could produce a dangerous spark. Simply put, when it comes to safe plant sanitation, not just any vacuum will do.
Make sure your vacuum is certified “explosion-proof”
An explosion-proof vacuum is explosion-proof to the core. This means that everything from the outer shell to the internal mechanics is grounded and constructed of non-sparking materials like stainless steel. Some industrial vacuum companies offer basic models “dressed up” with a few anti-static accessories and tell you that they are suitable for explosive materials. These imposter machines can still create arcs, sparks or heat that can cause explosions.
Purchasing an explosion-proof vacuum, approved by a nationally recognized testing laboratory such as the Canadian Safety Association (CSA) or Underwriters Laboratories (UL) will protect you from imposters. Your industrial vacuum partner should be able to provide legal certification that the explosion-proof vacuum you purchase can be used in a particular NFPA-classified environment. That certification ensures every component in the vacuum – from the ground up – meets strict standards for preventing shock and fire hazards.
Explosion-proof industrial vacuums vs. intrinsically safe industrial vacuums
There are times when electricity is unavailable or undesirable. For these situations, air-operated vacuums are excellent alternatives to explosion-proof vacuums. However, just because a vacuum is air-operated doesn’t mean it’s explosion-proof. Safe pneumatic vacuums should be constructed of non-sparking materials and be outfitted with ignition-proof parts and accessories that meet the highest level of operational safety.
These special pneumatic vacuums are called “intrinsically safe” because there is no legal certification for “explosion-proof” pneumatic vacuums. Intrinsically safe vacuums should still meet the requirements for use in the NFPA-classified environment. Plant managers should beware of vacuum companies that refer to their pneumatic models as “certified explosion-proof.” Explosion-proof certification for air-operated machines simply does not exist.
Filtration
Superior filtration does not have to be sacrificed on an explosion-proof vacuum model. For peak safety and operating efficiency, an explosion-proof vacuum should have a multi-stage, graduated filtration system, which uses a series of progressively finer anti-static filters to trap and retain particles as they move through the vacuum. In order to prevent combustible dust from being exhausted back into the ambient air, a HEPA or ULPA filter can be positioned after the motor to filter the exhaust stream. Quality HEPA filters offer an efficient, effective way to trap and retain the smallest dust particles, down to and including 0.3 microns. An ULPA filter captures even smaller particles, down to and including 0.12 microns.
Spill Response
Spill response should also be taken into account when purchasing an explosion-proof vacuum. Although OSHA’s National Emphasis Program is specifically looking at companies that handle dry solids, manufacturers’ maintenance plants are also coming under the microscope. If workers might need to collect flammable or explosive chemicals, a wet-model explosion-proof vacuum should be considered – also available in both electric and air-operated versions.