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]

Just done it manually and I make it 0.03014m3

30 x 0.00054 = 0.0162
10 x 0.00032 = 0.0032
meter = 0.008

total = 0.0274

10% = 0.00274

Total = 0.03014

Don't think I've missed anything?

 

[REDSAW]

@~@

 

[tamz]

30 x 0.00053 = 0.0162 + 10 x 0.00032 = 0.0194 (IVp) + 10% (IVf) = 0.02134 + 0.008 (IVm) = 0.02934 x 1.5 = 0.04401

If the pipe is feeding a boiler just turn it on. It will purge itself to a source of ignition.

 

[REDSAW]

Just done it manually and I make it 0.03014m3

according to this app on a g4 meter with 35m of 22mm no fittings comes to 0.0305m3

 

[REDSAW]

30 x 0.00053 = 0.0162 + 10 x 0.00032 = 0.0194 (IVp) + 10% (IVf) = 0.02134 + 0.008 (IVm) = 0.02934 x 1.5 = 0.04401

If the pipe is feeding a boiler just turn it on. It will purge itself to a source of ignition.

with a wooosh!

 

[Masood]

according to this app on a g4 meter with 35m of 22mm no fittings comes to 0.0305m3

Where are you getting 35m of 22mm? I thought we were looking at 30m x 28mm + 10m of 22mm??

 

[tamz]

It will probably need resetting a couple of times but it will light as normal.

 

[GrahamM]

Every app you use will prob give different answer.
If you want accuracy you need go old school and work out using your fingers and toes with standardised formula.
I got 0.02934 volume for a G4 meter.

 

[Masood]

30 x 0.00053 = 0.0162 + 10 x 0.00032 = 0.0194 (IVp) + 10% (IVf) = 0.02134 + 0.008 (IVm) = 0.02934 x 1.5 = 0.04401

Tamz, I was taught you only multiply x 1.5 of pipework is 35mm or over, or you have a U16 or bigger meter...

 

[GrahamM]

Just done it manually and I make it 0.03014m3

30 x 0.00054 = 0.0162
10 x 0.00032 = 0.0032
meter = 0.008

total = 0.0274

10% = 0.00274

Total = 0.03014

Don't think I've missed anything?

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

 

[tamz]

Technically if its a g4/U6 and pipework 28mm or under you don't need to bother working out the IV. The PV is 5 x cyclic volume (0.002) = 0.01

 

[Masood]

Every app you use will prob give different answer.
If you want accuracy you need go old school and work out using your fingers and toes with standardised formula.
I got 0.02934 volume for a G4 meter.

You've added 10% to the pipework before adding meter volume, right?

 

[Masood]

Technically if its a g4/U6 and pipework 28mm or under you don't need to bother working out the IV. The PV is 5 x cyclic volume (0.002) = 0.01

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

 

[GrahamM]

You've added 10% to the pipework before adding meter volume, right?

yip.

 

[REDSAW]

Where are you getting 35m of 22mm? I thought we were looking at 30m x 28mm + 10m of 22mm??

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