B
Blumper
Hello all, I'm currently studying for my initial ASC assessment and was wondering if any of you fellas can help me with a niggling issue I have re purging. I know all the claculation methods for volume etc, but on the actual process my tutor taught that you open the furthest point on the pipework, open the ECV and alow the calculated volume to pass. I asked him that where you might for example have a 5 mtr long 15mm branch to a cooker point, would the gas not possibly 'compress' or at least 'hold' the air in that branch as it passed throught the main pipe to the furthest point, effectively not doing a complete purge. He advised that you open the ECV slowly and the slow rate will draw the air from the branches and fully purge the pipework, he advised that you didn't need to open each branch. Now reading the CITB G2 book, that advises a procedure of opening the furthest branch, allowing an amount to pass, then repeat at each branch until the calculated volume has passed. That to me would make complete sense as it did in the classroom, as you ensure complete purging......? in addition to this conflicting advice, the G2 advises that if the volume is greater than 0.02m, the purge gas must be ignited at the purge point....but does that then mean that even though your purging a percentage of the volume at each point, it must be ignited at each point...? ( I know the total volume of gas and its build up would constitute a risk and hence the igniting, but if the main pipe purge was ignited do the smaller perentage small branch purge volumes have to be ?....and also are the purge volume calculations to be taken as a 'minimum' volume, or the correct volume ?
Sorry if that all seems to be a little too intense, I really should be in the bloomin pub right now ..... but I can't move on until the niggling doubt has gone away and I'm a stickler for wanting to get everything bang on....
cheers fellas.
Sorry if that all seems to be a little too intense, I really should be in the bloomin pub right now ..... but I can't move on until the niggling doubt has gone away and I'm a stickler for wanting to get everything bang on....
cheers fellas.