Standard for Piping Corrosion allowance rate ?

[drakkkko]

Hi.

Is there any standar wich define corrosion allowance rate for differents materials pipes ? I need to answer to client to justify the tipical value of corrosion, referred in any standard.

Thanks in advance!!.

 

[XL83NL]

I don't believe there are.
For plain grade CS piping system (A106-B etc), 1 mm for very mild up to 3 mm for very corrosive services is normal.
For plain grade SS piping systems (304, 316 etc), 0 for non-corrosive up to 1 mm for corrosive services is normal.

 

[MJCronin]

This subject has been discussed many, many times on eng-tips.

The selection of a corrosion allowance is subjective and is based on the expected corrosion of the process fluid AGAINST the selected piping materials........ if no corrosion expected, a zero CA is justified.

MJCronin
Sr. Process Engineer

 

[weldstan]

While there is no "standard" there are normal practices for piping. For mildly corrosive service in carbon and low alloy steels, 1/16" CA is often specifired. For more severe service, 1/8" CA is often specified.
For stainless steels, Nickel base alloys and titanium alloys, CA is most often 0.

CA must reflect the severity of corrosive service and the planned, safe life of the system.

 

[DSB123]

Corrosion rates are generally determined by experiment/test. You should ask the Client for these corrosion rates and then you may establish a reasonable corrosion allowance. I once had a particularly aggressive "fluid" which no one would provide corrosion rates so I chose a corrosion allowance of 9mm and informed the Client of this fact.

 

[weldstan]

As per DSB123, when we established high corrosion rates (1/4") to meet the customer's metallurgy, it was done to last at least through the warranty period.