AS4343 Hazard Level for Vacuum Tank

[CSGWB]

I am currently reviewing a vacuum tank mounted on the back of a truck (typical sucker truck) and trying to determine if it does or does not require design registration for use in an Australian State. The Tank is truck mounted, 16500L and capable of operation between 40kPag and full vacuum. It is used for extraction and collection of non harmful liquids (water etc), however operation starts empty (100% filled with air).

My calculations to AS4343 indicate that it would be Hazard Level C due primarily to the ability to see full vacuum and full of a non harmful gas (air). This would require registration, however the owner assures me that he is not aware of any such tank/vessel being registered.

Am I missing something or over complicating the process by assuming air (NHG) as the worst case?
Can anyone point me to a clause anywhere (AS1210, AS4343, legislation) that would exempt the design registration process for a vecuum only vessel?


Thanks

CSGWB.

 

[DavidOC]

There used to be exemptions in the QLD Workplace Health and Safety Regs for some vacuum vessels, however, I believe current legislation only looks at hazard level.

See Schedule 4 in this link for the old requirements.

http://www.legislation.qld.gov.au/LEGISLTN/REPEALED/W/WorkplHSR89_01_.pdf

 

[CSGWB]

DavidOC

I had considered that the old legislation may be playing a part in this situation with the existing fleet of vehicles. With the legislation changing only a few years ago it would make sense that this industry may not be fully aware of the change in requirements. The old legislation did exclude single wall static vessels design only for external pressure,... and vessels operating between 0 and 40C and upto 1750kPa internal pressure that contain non-toxic, non flammable .... substances. These vessels sort of fit into this category. I am not sure however if a road tanker, even if depressurised during transport, could be classed as static.

Regards

CSGWB

 

[DavidOC]

If depressurised during transport it is a static vessel. See AS 1210 3.26.2.

 

[CSGWB]

Thanks DavidOC. I agree with your assessment.

CSGWB