Page 258 - Centrifugal Pumps Design and Application

Slurry Pumps 231

Table 13-2
Alloys for Abrasion Resistance
(Properties Sensitive to Carbon Content Structure)
Alloy Properties
Tungsten carbide Maximum abrasion resistance.
composites Worn surfaces become rough.
High-chromium Excellent erosion resistance.
irons Oxidation resistance.
Martensitic iron Excellent abrasion resistance.
High compressive strength.
Cobalt base alloys Oxidation resistance.
Corrosion resistance.
Hot strength and creep resistance.
Nickel base alloys Corrosion resistance. May have
oxidation and creep resistance.
Martensitic steels Good combination of abrasion and
impact resistance.
Pearlistic steels Inexpensive. Fair abrasion and im-
pact resistance.
Austenitic steels Work hardening.
Stainless steels Corrosion resistance.
Manganese steel Maximum toughness with fair
abrasion resistance. Good metal-
to-metal wear resistance under im-
pact.

pumped and the particle size is limited to fines below 7 mesh in size. At
velocities above 35 ft/sec the rubber may not have sufficient time to flex
and absorbs all the impact, and as result, wear will increase. Natural rub-
ber is limited in temperature to 150°F or less.
Where oils are present, a synthetic rubber such as neoprene should be
used; however the addition of fillers will have a detrimental effect on
wear resistance.
Elastomer materials generally have good corrosion resistance, but care
must be exercised to prevent the slurries from penetrating behind the cas-
ing and causing corrosive damage.
Natural rubber-lined pumps with a durometer hardness of 40 shore A
are usually limited to about 120 feet total head. Higher heads can be gen-
erated if fillers are added to increase hardness.