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

 

[REDSAW]

are you in scope?

 

[ShaunCorbs]

+1 and what you feeding cant be much after 40m total

and a bunsen burner

 

[mutley racers]

are you in scope?

Sure, it is still domestic as it comes in at 0.03255

 

[REDSAW]

Sure, it is still domestic as it comes in at 0.03255

no bends eh?

 

[REDSAW]

no bends eh?

just found the new baxi app does not cater for anything larger than 22mm??????

 

[mutley racers]

no bends eh?

Only 6 fittings on the run

 

[ShaunCorbs]

Only 6 fittings on the run

appliance load in kw

and any fittings on the 28mm or is that included in the above?

 

[REDSAW]

sorry mutt, but i disagree!! probably wrong though!
whats the meter?
g4 i make it 0.04614m3

 

[stani]

Using gas app. It's 0.3561

 

[mutley racers]

sorry mutt, but i disagree!! probably wrong though!
whats the meter?
g4 i make it 0.04401m3

So to calculate the installation volume it is G4 metre 0.008 + 30 metres 28 mm 0.0162 + 10 metres 22mm 0.0032 + 10 % for fittings is 0.0301?

Have I made a mistake some where

 

[stani]

Using gas app. It's 0.3561

Didn't realise G4 meter

Says 0.04401

 

[REDSAW]

So to calculate the installation volume it is G4 metre 0.008 + 30 metres 28 mm 0.0162 + 10 metres 22mm 0.0032 + 10 % for fittings is 0.0301?

Have I made a mistake some where

must be! 30mx28mm is 0.0387m3 & 10mx22mm is 0.01728m3 !!

according to the rays gas app...
30mx28mm + 10mx22mm not adding any fittings its 0.04401m3 or 0.04614m3 with fittings!!

think youve been hoping to do it in 10mm aint u? lol

 

[ShaunCorbs]

must be!
according to the rays gas app...
30mx28mm + 10mx22mm not adding any fittings its 0.04401m3 or 0.04614m3 with fittings!!

you got a link to rays app?

 

[REDSAW]

you got a link to rays app?

Gas app uk, its on the app store ot android free http://www.gasapp.co.uk/

 

[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

 

[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...