Test yourself with Purge Volumes!!

[Tom Jackson]

18m of 2"
10m of 1.5"
10m purge hose of 25mm nominal bore
U40/G25 meter installed

Please calculate IV and PV and Purge Time

show your workings so i know youre not using your app!

point in this being i keep getting it wrong according to app but know im right!!!

 

[rpm]

Interesting first post Tom. Care to introduce yourself?

 

[Tom Jackson]

Worked in gas since i left school at 16 for transporter, currently doing commerical gas metering for them

 

[lame plumber]

Interesting first post Tom. Care to introduce yourself?

His name is Tom....... and like me doesnt believe in apps to work things out 🙂 but I dont do commercial so cant help, he needs croppie or Tamz using their abbacus to calculate the answer.

 

[Knappers]

Couldnt resist a chalenge

Is it
PV 0.247m2
Pt 3min 20sec ish

 

[Knappers]

(3600(1.5((0.0024×18)+(0.0015×10)+(0.00064×10))))÷4.5

:46:

 

[Tom Jackson]

my app says:

Pipe IV: 0.054200
Pipe PV: 0.89430
Total PV: 0.199030

Purge time: 159s
🙁

 

[Knappers]

I used TPCP1A and would have to chk workings
Does TPCP1 have different outcome?

 

[SmokeyJ]

I make it
Ivm -
U40 meter - 0.067m3
Ivp -
2" - 18 × 0.0024 = 0.0432
1.5" - 10 x 0.0015 = 0.015
0.0432 + 0.015 = 0.0582 m3
Ivf -
10% of Ivp = 0.00582
Iv total
0.067 + 0.0582 + 0.00582 = 0.13102 rounded up = 0.14m3 installaton volume

Purge
pv of meter = 5 x 0.02 = 0.1 m3
Pv of pipework 1.5 x 0.0582 = 0.0873 m3
Pv of purge hose 1" - 10 x 0.00064 = 0.0064. 1.5 × 0.0064 = 0.0096 m3
Total purge volume 0.1 + 0.0873 + 0.0096 = 0.1969 m3 rounded up to 0.2 m3
Purge time = minimum flow rate for 2" is 4.5 m3h
0.2 x 3600 ÷ 4.5 = 160 seconds

Any good?

 

[Unregistered]

Correct!!!

 

[SmokeyJ]

I used TPCP1A and would have to chk workings
Does TPCP1 have different outcome?

IGE/UP/1A and IGE/UP/1 - No difference between purge calculations.
I flare when commissioning if possible, so much easier

 

[Dotty]

Moving off open forum.

 

[Chalked]

Na. Just pull it through the hob!

Would be a big hob tho! :computer:

 

[tamz]

His name is Tom....... and like me doesnt believe in apps to work things out 🙂 but I dont do commercial so cant help, he needs croppie or Tamz using their abbacus to calculate the answer.

And at half 3 in the morning following 3/4 a bottle of jura i'll be fu kd if i';m gonny work it out 😉

 

[tamz]

Correct!!!

Well it might well be but wgaf