Material Construction
Carbon Steel
+
Low cost, easy to fabricate, abundant, most common material. Resists most alkaline environments well.
-
Very poor resistance to acids and stronger alkaline streams. More brittle than other materials, especially at low temperatures.
Stainless Steel
+
Relatively low cost, still easy to fabricate. Resist a wider variety of environments than carbon steel. Available is many different types.
-
No resistance to chlorides, and resistance decreases significantly at higher temperatures.
254 SMO (Avesta)
+
Moderate cost, still easy to fabricate. Resistance is better over a wider range of concentrations and temperatures compared to stainless steel.
-
Little resistance to chlorides, and resistance at higher temperatures could be improved.
Titanium
+
Very good resistance to chlorides (widely used in seawater applications). Strength allows it to be fabricated at smaller thicknesses.
-
While the material is moderately expensive, fabrication is difficult. Much of cost will be in welding labor.
Pd stabilized Titanium
+
Superior resistance to chlorides, even at higher temperatures. Is often used on sea water application where Titanium's resistance may not be acceptable.
-
Very expensive material and fabrication is again difficult and expensive.
Nickel
+
Very good resistance to high temperature caustic streams.
-
Moderate to high expense. Difficult to weld.
Hastelloy Alloy
+
Very wide range to choose from. Some have been specifically developed for acid services where other materials have failed.
-
Fairly expensive alloys. Their use must be justified. Most are easy to weld.
Graphite
+
One of the few materials capable of withstanding weak HCl streams.
-
Brittle, very expensive, and very difficult to fabricate. Some stream components have been know to diffusion through some types of graphites.
Tantalum
+
Superior resistance to very harsh services where no other material is acceptable.
-
Extremely expensive, must be absolutely necessary.
Tidak ada komentar:
Posting Komentar
SILAHKAN DI KOMEN YA