5 replies to this topic

[asade abiodun]

Hi,
Please can anyone help me with information on how to determine the pipe diameter for vent.

I have used API 2000 to determine the vent requirement for my tank. Its an atmospheric tank.

regards

[latexman]

Please refer to Crane Technical Paper 410. It is considered one of the best references on how to apply fluid mechanics to non-complicated situations. It can be purchased online at www.flowoffluids.com That website was down when I just looked, hopefully only temporarily.

[Padmakar Katre]

Dear Asade Abiodun,

I am giving the link here below where the same thread is discussed and it has reply of our respected

chemical engineers GURU ......Mr Art Montemayer.

http://www.eng-tips....d=151637&page=1

http://www.eng-tips....d...967&page=10

http://www.protectos...m/ventrain.html

http://www.gjerde.com/services.htm

Regards,

Padmakar Katre

[JEBradley]

If this is just a straightforward vent and not an emergency vent (so we arent talking PSVs and bursting discs)... AND the chemical is safe....then Ive always used the rule of thumb that the vent line should be twice the diameter of the feed line. This is obviously assuming a single feed. You can extrapolate this to:

Vent Area = 2 x Feed Area.

[latexman]

Ive always used the rule of thumb that the vent line should be twice the diameter of the feed line.

If vent diameter = 2 x feed diameter, then vent area = 4 x feed area.

[JEBradley]

Well there you go assuming a circular cross-section

It is only a vague heuristical technique - don't use it if you have some exotic system or weird chemical.

....But do go ahead and use it if you have a water storage tank (warning - put some kind of filter on the top of the vent line to stop dead rats falling in!!)

Thanks for pointing out my mistake btw - and its caused me to realise it a mistake ive followed through into practice. I had a tank filling from a 3" line which originally had a 6" vent. A later mod. caused by space limitations made me exchange it for 2-off 3" lines. Ive only just realised that doesn't add up