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The Effect of Common Fillers on the Construction of Pumping Equipment
Filler is a general term used to describe an organic, non-metallic or metallic powder
added to resins. They can extend material for cost reduction and/or enhance the material's
mechanical properties.
Talc and calcium carbonate are soft fillers commonly used as extensions in materials.
These fillers, or ones similar to them, can generally be used in pumping equipment of
standard construction (mild steel hard chromed).
Silica and alumina (aluminum oxide) are fillers usually added to materials to enhance
mechanical or thermal properties. These types of fillers often require special pump
construction of nitrided steel or silicon carbide (ceramic) due to their hardness,
physical size and/or shape.
A scale that measures the hardness of a material by its ability to indent or scratch
another material was introduced in 1812 by Friedrich Mobs, a German mineralogist. The
Mohs' Scale for minerals is arranged in a scale from 1 to 10, with I being the softest
and 10 being the hardest. The Knoop Scale was developed as another method to determine
hardness of a greater variety of materials.
Both the Mobs' Scale and the Knoop Scale provide important information concerning
hardness of fillers as they relate to various pump materials of construction or other
materials.
The charts below provide data on various fillers that affect the construction of
pumping equipment. For specific recommendations on pump construction for a particular
material, contact Liquid Control's Technical Service Department.
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Filler Hardness Chart
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|
Material
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Commonly Used Fillers
|
Hardness Number
|
|
Mohs
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Knoop
|
|
Pitch (for optical polishers)
|
Talc
|
1
|
1-22
|
|
Gypsum
|
|
2
|
32
|
|
Calcite
|
Calcium Carbonate
|
3
|
135
|
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Flourite
|
Aluminum Trihydrate
|
4
|
163
|
|
Flint Glass
|
|
---
|
180-390
|
|
Apatite (parallel to axis)
|
|
5
|
360
|
|
Apatite (perpendicular to axis)
|
|
5
|
430
|
|
Crown Glass
|
|
---
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420-470
|
|
Fused Quartz
|
|
---
|
475
|
|
Albite
|
|
6
|
490
|
|
Orthoclase
|
|
6
|
560
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Crystalline quartz (parallel to axis)
|
|
7
|
710
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Crystalline quartz (perpendicular to axis)
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Silica
|
7
|
790
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Nitrided annealed high-speed steel
|
|
---
|
800
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Chromium plate
|
|
---
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850-900
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Carboloy
|
|
---
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1,050
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Nitrided hardened high-speed steel
|
|
---
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1,100
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Topaz
|
|
8
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1,250
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Alundum
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Alumina (Aluminum Oxide)
|
9
|
1,635
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Silicon carbide
|
|
---
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2,000
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Boron carbide (molded)
|
|
---
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2,230
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Diamond
|
|
10
|
8000-8500
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Particle Size Chart
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Sieve Size or Screen Mesh
|
Opening
|
|
Inches
|
Microns
|
Millimeters
|
|
10
|
0.0787
|
2000
|
2.0000
|
|
20
|
0.0331
|
840
|
0.8400
|
|
30
|
0.2320
|
590
|
0.5900
|
|
40
|
0.0165
|
420
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0.4200
|
|
50
|
0.0117
|
297
|
0.2970
|
|
60
|
0.0098
|
250
|
0.2500
|
|
70
|
0.0083
|
210
|
0.2100
|
|
80
|
0.0070
|
177
|
0.1770
|
|
100
|
0.0059
|
149
|
0.1490
|
|
120
|
0.0049
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125
|
0.1250
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|
140
|
0.0041
|
105
|
0.1050
|
|
170
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0.0035
|
88
|
0.0880
|
|
200
|
0.0029
|
74
|
0.0740
|
|
230
|
0.0024
|
62
|
0.0620
|
|
270
|
0.0021
|
53
|
0.0530
|
|
325
|
0.0017
|
44
|
0.0440
|
|
400
|
0.0015
|
37
|
0.0370
|
|
500
|
0.0014
|
31
|
0.0310
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Dispensing Technologies
