Ventilation | Permit-Required Confined Spaces

Ventilation is the process of continuously moving fresh, uncontaminated air through a confined space. Ventilation dilutes and displaces air contaminants, assures than an adequate supply of oxygen is maintained during entry, and exhausts contaminants formed by processes such as welding, oxy-fuel gas cutting, or abrasive blasting. Oxygen levels must be maintained within a range of 19.5 to 23.5 percent.
Add a note hereVentilation by a blower or fan may be necessary to remove harmful gases and vapors from a confined space. There are several ventilating methods and equipment to choose, depending on the size of the confined space openings, gases to be exhausted, and source of makeup air.
Add a note hereEquipment selection considerations include the:
§  Add a note herePhysical structure of the space,
§  Add a note hereSpace’s previous contents,
§  Add a note hereExistence of natural drafts,
§  Add a note hereNumber and location of any openings, and
§  Add a note hereNature of any contaminant-producing tasks that may be performed in the space.
Add a note hereBecause ventilating may create the potential for static electricity, always follow appropriate bonding and grounding procedures.
Add a note hereUnder certain conditions where flammable gases or vapors have displaced the oxygen level, but are too rich to burn, forced air ventilation may dilute them until they are within the explosive range. Typically, an opening is made in the top or side of the space and clean air s blown into it. Dilution works best with low toxicity and concentration levels and when the contaminants are well distributed.
Add a note hereVentilation should be continuous where possible, because in many confined spaces, the hazardous atmosphere will form again when the flow of air is stopped. Be sure that the source of air intake is not placed where it can draw carbon monoxide (as from an idling vehicle parked close by) or other contaminants into the space.
Add a note hereA common method of ventilation requires a large hose, one end attached to a fan and the other lowered into a manhole or opening. For example, a manhole would have the ventilating hose run to the bottom to blow out all harmful gases and vapors. The air intake should be placed in an area that will draw in fresh air only.



3 comments:

Roof Ventilators said...

Great post, Fresh air ventilators draw, filter and regulate outside air temperature. It also provides a constant source of clean, fresh air without the expensive cost. Thanks for sharing this.
nilyvn

cisyuvraj said...

Confine space rescue operations are necessary for the safety of employees.

http://naturalairventindia.com/ said...

your article fanttastic. thanks in informahie.....from Industrial Ventilators bangalore

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