Below are two tables with ...

Below are two tables with guidelines for corrosion allowance

 

Corrosion allowance for steel pipes	mm
Superheated steam	0.3
Saturated steam	0.8
Steam coils in cargo tanks and liquid fuel tanks	2.0
Feed water for boilers in open circuit systems	1.5
Feed water for boilers in closed circuit systems	0.5
Blow-down systems for boilers	1.5
Compressed air	1.0
Hydraulic oil	0.3
Lubricating oil	0.3
Fuel oil	1.0
Thermal oil	1.0
Fresh water	0.8
Sea water	3.0
Refrigerants referred to in Section 13	0.3
Cargo systems for oil tankers	2.0
Cargo systems for ships carrying liquefied gases	0.3

Notes..

• For pipes passing through tanks, an additional corrosion allowance is to be considered in order to account for the external corrosion.
• Note 2.. The corrosion allowance of pipes efficiently protected against corrosion may be reduced by no more than 50%.
• Note 3.. When the corrosion resistance of alloy steels is adequately demonstrated, the corrosion allowance may be disregarded.

 

Corrosion allowance for non-ferrous metal pipes	mm
Copper	0,8
Brass	0,8
Copper-tin alloys	0,8
Copper-nickel alloys with less than 10% of Ni	0,8
Copper-nickel alloys with at least 10% of Ni	0,5
Aluminium and aluminium alloys	0,5