Gas Pipe Sizing Formula

[rQb]

Hi,

I'm chasing a couple of things to assist with design of a gas service for a high rise apartment building.

a) The most suitable formula to use in sizing the pipework. System would be 100 mm and supply pressures 2.75 kPa thru to 70 kPa.
b) As I understand it equivalent lengths are typically used for fittings, is there a metric source I could refer to with this data?
c) Some information on diversities for residential gas supplies, what sort of percentage or method to determine diversity is typically used?

I'm dealing in metric.

One formula I have been sent is as follows for calculating outlet pressure:

P = ( Absolute Inlet Pressure^2 - ( (m3/hr / Constant)^2 * Specific Gravity * Length) / Diameter ^ 5) ) )^0.5

Anyone able to confirm which formula it is and if suitable?

Thanks in advance

K

 

[EmmanuelTop]

I'd suggest you to obtain Crane TP410

http://www.flowoffluids.com/publications/crane-tp-410.aspx

- it is well worth the money.
Answers on your first and second question can be found there.

Also look at the International fuel gas code

https://law.resource.org/pub/us/code/ibr/icc.ifgc.2009.pdf

Dejan IVANOVIC
Process Engineer, MSChE

 

[EmmanuelTop]

Some folks have had problems accessing the law.resource.org in the past so I'm uploading the whole IFGC here.

Dejan IVANOVIC
Process Engineer, MSChE

 

[rQb]

Thank you for your assistance.

For reference should anyone come across this post, with regards to diversity, I found two references.

a) International Mechanical Code 1988

http://publicecodes.cyberregs.com/icod/imc/1998/icod_imc_1998_13_par017.htm

and

b) ASPE Data Book Volume 2, Figure 7-5 Typical Diversity Curve for Gas Supply to High Rise Apartments

Cheers

K

 

[EmmanuelTop]

See also ftp://law.resource.org/pub/nz/ibr/as-nzs.5601.1.2010.pdf and

http://www.b3pe.com/training/docs/demand_estimating.pdf

Dejan IVANOVIC
Process Engineer, MSChE