| Degrees of work | Air consumption (ltrs/minute)
|
Duration of cylinder having 1800 ltrs capacity(minutes) |
Duration of cylinder having 1800 ltrs capacity(minutes) |
||
| Resting | 8 -12 | 150 -100 | 225 -150 | ||
| Light Work | 12 – 20 | 100 – 60 | 150 – 90 | ||
| Moderate Work | 20 – 40 | 60 – 30 | 90 – 45 | ||
| Heavy Work | 40 – 60 | 30 – 20 | 45 – 30 | ||
Please note in the above table the total full duration is given. Reduce the safety margin( 10 MIN) from the above table to get the nominal working duration.
- Here we have taken an average consumption of 40 ltrs of air per minute being required by human being when doing heavy work.
- If we have a 1200 ltrs of fully charged cylinder then:
- Nominal work duration= 1200/40= 30 min. – 10 min ( safety margin taken as the alarm whistle will start blowing indicating the wearer to come out to safe atmosphere) so it is 20 min.
