Hi,... calling a well read gas engineer....HELP!!

[Bakiibak]

Need advice on purging vols ?

 

[Dan]

Welcome to Plumbing Forum | Plumbing Advice | Plumbers Forums | A forum for plumbers advice in the UK!

Hi Bakiibak and welcome to UKPlumbersForums.co.uk!

 

[Bakiibak]

Hi, guys anyone out there who is a whiz on explaining purging volumes U6 metric up to 28mm pipe......?? I will try and explain what is confusing me so bear with me...hear goes, I have a few questions got my exams due soon so really got to get this in my head (i know you will all understand what am goin through!!)

I know the amounts 0.01m3 0.35 ft3 etc but don't know how we get to these figures. I understand its 5 x the badge cap. and 4 x for purge and cap but how do we get to the figure 0.01 when the badge cap. is V = 2dm3 (G4) am I doing this right assuming 2dm3 /1000 = 0.002 then multiply by 5 to get 0.01 m3 therefore 4 x = 0.008 (0.01m3) is this correct?

Also not quite understanding how the imperial calc. work out in my notes:
5 x 0.071 = 0.355ft3 I understand that!! but for 4 x 0.071 = 0.284 ft3 is this correct??

in my notes I have 4 x 0.142 = 0.568ft3 which one is right my notes cap is suddenly 0.0142
regards dave

 

[PlumbBobBob]

hi welcome to the forum

steve

 

[Toddyplumb]

Where r u getting the 4X from . Up to 28mm it is simply 5 X badged capacity.

 

[tamz]

As Toddy said i don't know where you are getting the 4 x from. You are confusing yourself. FORGET THE 4!
Purge volume is simply 5 x cyclic volume (capacity per revolution / badged capacity) which on a G4/U6 is 0.002m3 x 5 = 0.01m3. (imperial, 0.071ft3 x 5 = 0.355ft3) On an E6 although the volume of the meter is smaller, as there is no given cyclic volume you still purge 0.01m3
The IV's of meters is irrelevant for purging they are only used when calculating the IV of the system.
You should have this in your Viper book (or whatever one you have) or look up IGE-UP-1B which should be available to you.

 

[Bakiibak]

Thanks for that, think I was looking too deep into it. It's because the assesser called me on the phone because I had made a mistake on my portfolio and put M^3 purge vol. for an imperial meter. He wanted to me to tell him over the phone what was the purge vol. for an imperial meter and I said it was 3 and a half increments on the dial,
0.35ft^3. so then he asked me why....is it 0.35ft^3 and what is it if there was no pipework and was just to purge and cap the meter, which through me. I have looked in all the books, I have the corgi and course work folder, I do need to get some more books including the viper i know thats a good one. When I called him back he said that it's 4 x the badge capacity because the U6 meter has 4 bellows or chambers or something in it. So he wants me to send him an email explaining all this, as supportive evidence for potfolio.
Now the thing is, I found in my notes from when I went to London to do the 10 day intro course. A note saying:-...... purge and cap (4 X badge capacity)
4 X 0.142
Thats whats confused me.

Strange init, never mind am just about to call around a few of the engineers I have been working with, maybe I should just call the assessor back but am scared he'll send my potfolio back lol.
Anyway thanks for the reply guys and i'll keep you posted

regards Dave