Purging long gas supply

[mutley racers]

I have a job where I need to run 30 metres of 28 mm and 10 metres of 22mm copper tube. Now there is no gas hob in the place so I need to light the gas while purging. What right do you guys make up in this scenario. Cheers

 

[Masood]

Almost right. :yes:
Went wrong by adding the meter before adding your 10%.

Now that's a funny thing. When I first did ACS, I was taught to do your method. Subsequently I was taught to add meter volume first and then add 10%.

 

[Masood]

that size is the iv of your result/size over 35m of 22mm

Sorry Martin, I don't follow?

 

[tamz]

True, as that is minimum purge vol but I want to check whether I was taught wrong about the multiplying by 1.5?

No its right enough.
You would only bother working out the IV for a purge if there was > 28mm or a G10/U16 on it so it is irrelevant in this case anyway.

 

[tamz]

Now that's a funny thing. When I first did ACS, I was taught to do your method. Subsequently I was taught to add meter volume first and then add 10%.

Some acs centres have their heads up their rses.
Gimme a minute and i'll post a pic from UP1B.

 

[Masood]

Some acs centres have their heads up their rses.
Gimme a minute and i'll post a pic from UP1B.

Just checked the Construction Skills textbook. 10% added to pipework and then meter volume added. So yeah, the worksheet the assessment centre gave us was wrong!

Although, I noticed something else in the book - we've all been adding 0.008m3 as meter volume, but that is meter internal volume. Meter purge volume is given as 0.01m3 for U6/G4.

God, I'm sad...

 

[REDSAW]

according to this app (uk gas app) with a g4 meter with straight run of 35mx22mm pipe with no fittings comes to 0.0305m3 so a 30m run of 28mm and 10m of 22mm with 6 fittings cant equate to the same?

looking at same volume

 

[tamz]

 

[REDSAW]

Just checked the Construction Skills textbook. 10% added to pipework and then meter volume added. So yeah, the worksheet the assessment centre gave us was wrong!

Although, I noticed something else in the book - we've all been adding 0.008m3 as meter volume, but that is meter internal volume. Meter purge volume is given as 0.01m3 for U6/G4.

God, I'm sad...

the inspectors will be busy next week.lol

i rely on my app's or last resorse get the book out of van.
did my resits last week and they said 'right get your prefered app ready for purging/pipes & vents.lol

 

[GrahamM]

Just checked the Construction Skills textbook. 10% added to pipework and then meter volume added. So yeah, the worksheet the assessment centre gave us was wrong!

Although, I noticed something else in the book - we've all been adding 0.008m3 as meter volume, but that is meter internal volume. Meter purge volume is given as 0.01m3 for U6/G4.

God, I'm sad...

Yip. For standard G4/E6 upto 28mm pipe the standard purge is 0.01.
Bigger meter and or greater than 28mm pipe then you need to calculate.

 

[REDSAW]

View attachment 25827

feck! cant see your bank details on there!

 

[tamz]

Meter purge volume is given as 0.01m3 for U6/G4.

Only if pipe is no bigger than 28mm (5 times cyclic volume which used to be called badged capacity)

 

[REDSAW]

Yip. For standard G4/E6 upto 28mm pipe the standard purge is 0.01.
Bigger meter and or greater than 28mm pipe then you need to calculate.

depends!

 

[mutley racers]

Wow.a lot of info in there guys. Thank you. So basically, all I need to do is purge 0.01 and all is well as no 35mm pipe or u16 meter.

So I am within scope.

I know some boilers have a purge setting on them so think I shall do it this way


Thanks for all the help guys. I appreciate it.

 

[mutley racers]

Just one more thing to clarify, it is the installation volume that makes it commercial and not the purge volume correct? Which is what tamz's diagrams explains

 

[REDSAW]

Wow.a lot of info in there guys. Thank you. So basically, all I need to do is purge 0.01 and all is well as no 35mm pipe or u16 meter.

So I am within scope.

I know some boilers have a purge setting on them so think I shall do it this way


Thanks for all the help guys. I appreciate it.

no!
the installation volume is>0.035 and by the book..its out of scope!
whether it matters could be debateable but you wouldnt do it near an inspector
perhaps were all on a learning curve here, one for the acs reassesment center when tickets are due.haha

however, based on this there in scope and simular to what tam said, so 'grey area'?
http://shop.igem.org.uk/download/document/Pages from IGE-UP-1B Edition 2.pdf
http://shop.igem.org.uk/download/do...UP-1A Edition 2 (Reprint with amendments).pdf