8 replies to this topic

[Eprocess]

I am about to set velocity limitation criteria for sulfuric acid line sizing, but I can not find any reliable standard or practice. I have found some figures on the internet, and I want to know if they are OK or not. The operating temperature is 160 F.

Carbon steel piping 1-3 ft/s (for pure acid)

Stainless steel piping 1-6 ft/s (for pure and diluted acid)



Thank you

Edited by Eprocess, 16 October 2011 - 09:39 AM.

[ankur2061]

Eprocess,

Take a look at the link below and the spreadsheet attached in the post:

http://www.cheresour...__fromsearch__1

Regards,
Ankur.

Quick note from the admin: Excellent work Ankur!

[irprocess]

Recommended velocity as per both following concentration is 4 ft/sec

88-93% =>proposed material is 316 SS, lead

and for 93-100 % => proposed pipe material is Cast iron; Steel, Sch 80

[breizh]

Hi Eprocess,

Consider this resource , a lot of informations related to H2SO4.

Hope this helps
Breizh

Edited by breizh, 16 October 2011 - 01:49 AM.

[kkala]

The "utilisation H2SO4.pdf" seems quite useful, summarizing a lot of sulfuric acid properties. It explains why there is low and high velocity limitation in pipe transport, that carbon steel contaminates acid with iron (undesirable in some cases), etc.
Perry, 5th edition (1973), Sec 23 Materials of construction, p. 23-14 Ferrous metals and alloys, writes: Carbon steel should not be used in contact with dilute acids. Thus it is not recommended with sulfuric acid below 90 per cent. Between 90 and 98 per cent, steel can be used up to the boiling point; between 80 and 90 per cent, it is serviceable at room temperature. Above 102 per cent, steel is good up to 140 oF".
The "utilization H2SO4.pdf" writes that carbon steel is commonly used for piping and tanks of above 77% H2SO4. Temperature should be kept below 100 oF (38 oC) wherever possible. Corrosion allowance for tanks should be 1/8" = 3 mm.
I know from a fertilizer factory that the 96% H2SO4 produced there can contact steel at room temperature, but not at high temperatures. So Perry was wrong and "utilization H2SO4.pdf" right on this point. 3 mm corrosion allowance is also recommended here for piping.
Breizh, can you advise source of "utilization H2SO4.pdf" ? Useful information, indeed.

[breizh]

Good day Kostas and other forum members ,
The reference is attached :


http://www2.dupont.c...ipment_FAQs.pdf

Breizh

[kkala]

So Dupont is the originator of the mentioned "utilization H2SO4.pdf". Thanks breizh

[breizh]

So Dupont is the originator of the mentioned "utilisation H2SO4.pdf". Thanks breizh

Again a lot of great stuff on internet and google is one of my favorite tool.

Edited by breizh, 22 October 2011 - 05:08 AM.

[jaibogo]

I am about to set velocity limitation criteria for sulfuric acid line sizing, but I can not find any reliable standard or practice. I have found some figures on the internet, and I want to know if they are OK or not. The operating temperature is 160 F.

Carbon steel piping 1-3 ft/s (for pure acid)

Stainless steel piping 1-6 ft/s (for pure and diluted acid)



Thank you

In my opinion you must to find a laminar flow, that is the better velocity in any specification pipe