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O-ring Design

date2025-05-11tags:meche:

O-Rings are torus-shaped (i.e. doughnut-shaped) objects made from elastomeric compounds such as natural or synthetic rubber, and are used to seal mechanical parts against fluid movement (air or liquid). O-Rings perform their sealing action by deforming to take the shape of their cavity, after being oversized to guarantee an predetermined interference fit. O-Rings are inserted into cavities defined as glands, and are typically used in one of two seal designs, axial or radial. These seal designs along with their gland geometries are shown in the following schematic:

attachment:_20240324_094037screenshot.png

An O-Ring is specified by its inner diameter, its cross-section diameter, its material hardness/durometer (typically defined by the Shore A hardness), and its material composition. In order for an O-Ring to seal against the movement of fluid, it must be compressed when seated inside the gland. A standard set of design guidelines exist to determine the proper O-Ring dimensions for radial and axial seals of a given dimension.

O-Ring Parameters and description

SymbolNameDescription
CS_tolCross-Section ToleranceManufacturing tolerance on the O-Ring cross-section diameter.
C_maxMaximum CompressionUpper bound for the cross-section compression (in %) when the O-Ring is seated in the gland; used as a design input.
C_minMinimum CompressionLower bound for the cross-section compression (in %) when the O-Ring is seated in the gland; used as a design input.
B_dBore DiameterInner diameter of the bore which confines the outer diameter of the O-Ring.
B_tolBore Diameter ToleranceManufacturing tolerance on the bore diameter.
G_dGroove DiameterMinimum diameter of the gland which confines the inner diameter of the O-Ring.
G_tolGroove Diameter ToleranceManufacturing tolerance on the groove diameter.
GWGroove WidthGroove length in the axial direction; must be large enough to accommodate O-Ring axial expansion.
IDInner DiameterDiameter of the inside edge of the cross-section.
CS_minMinimum Cross-Section DiameterLower bound on the cross-section diameter for a given set of input requirements.
CS_maxMaximum Cross-Section DiameterUpper bound on the cross-section diameter for a given set of input requirements.

Cross Section Diameter (inch) Recommended Tolerance (inch) CS < 0.104 0.003 0.104 < CS < 0.139 0.004 0.139 < CS < 0.210 0.005 0.210 < CS < 0.275 0.006 0.275 < CS 0.008

O-ring compatible materials

MaterialSea WaterFresh WaterAcetoneEthanolPropanolCarbonic AcidSulfuric Acid (Concentrated)Nitric AcidAcetaldehyde
Aflas041000440
Buna-N (Nitrile)441443111
Butyl444444014
Chemraz434444030
Epichlorohydrin031444114
Ethylene-Propylene444444001
Fluorocarbon431444000
Fluorosilicone441444000
Hypalon441444010
Kalrez444404442
Natural Rubber442444010
Neoprene331443001
Nitrile, Hydrogenated441444010
Polyacrylate010114011
Polysulfide114444110
Polyurethane, Cast001002000
Polyurethane, Millable041114001
Silicone431344004
Styrene Butadiene430443010
Teflon, Virgin444414444
Vamac441040100
import pandas as pd
df = pd.DataFrame(tbl[1:], columns=tbl[0])
df = df.set_index(df['Material'])
df = df.drop(columns=['Material'])
# print(len(list(df.columns)[0:]))

# Print only the materials that have some data
accepted_materials =  df[(df!=0).sum(axis=1) == len(list(df.columns))]
print(accepted_materials)

#print(accepted_materials[(accepted_materials==4).sum(axis=1) == len(list(accepted_materials.columns))] )
#print(df, "\n")

#+RESULTS:

Teflon

Chemicals Compatible with Teflon, Virgin

Acetaldehyde4Acetamide4Acetic Acid, Glacial4
Acetic Anhydride4Acetone4Acetophenone4
Acetyl Chloride4Acetylene Gas4Acrylonitrile4
Air below 200 C4Alkazene4Aluminium Acetate4
Aluminium Chloride4Aluminium Flouride4Aluminium Nitrate4
Aluminium Sulfate4Ammonia, Anhydrous4Ammonia, Gas, Cold4
Ammonia, Gas, Hot4Ammonium Carbonate4Ammonium Chloride4
Ammonium Hydroxide, Concentrated4Ammonium Nitrate4Ammonium Persulfate Solution4
Ammonium Phosphate4Ammonium Sulfate4Amyl Acetate4
Amyl Alcohol4Amyl Borate4Amyl Chloronaphthalene4
Aniline4Aniline Oil4Animal Oil4
Arachlor 12480Argon4Aromatic Fuel 50%0
Askarel Transformer Oil4ASTM Fuel A4ASTM Fuel B4
ASTM Fuel C4ASTM Fuel D0ASTM Oil Four0
ASTM Oil One4ASTM Oil Three4ASTM Oil Two4
Automatic Transmission Fluid4Automotive Brake Fluid0Beer4
Benzaldehyde4Benzene4Benzene Sulfonic Acid4
Benzine (Ligroin)4Benzoic Acid4Benzophenone0
Benzyl Alcohol4Benzyl Benzoate4Benzyl Chloride4
Bleach Liquor4Borax Solutions4Boric Acid4
Brake Fluid4Bromine Gas4Bromobenzene4
Bunker Oil4Butadiene Monomer4Butane4
Butter4Butyl Alcohol4Butyl Carbitol4
Butyl Cellosolve4Butyraldehyde4Calcium Carbonate4
Calcium Chloride4Calcium Hydroxide0Calcium Hypochlorite4
Calcium Nitrate4Calcium Sulfide4Carbitol 24
Carbolic Acid (Phenol)4Carbon Disulfide4Carbon Monoxide4
Carbon Tetrachloride4Carbonic Acid4Castor Oil4
Cellosolve4China Wood Oil, Tung Oil4Chloracetic Acid4
Chlordane0Chlorinated Solvents4Chlorine Dioxide4
Chlorine Trifluoride4Chlorine, Dry4Chlorine, Wet4
Chloroform4Chlorosulfonic Acid4Chrome Plating Solution4
Chromic Acid4Citric Acid4Cod Liver Oil4
Coffee0Coolanol Monsanto0Corn Oil4
Creosote, Coal Tar4Creosylic Acid0Crude Oil (Asphalt Base)4
Cyclohexane4Denatured Alcohol4Di-ester Lubricant MIL-L-78084
Diacetone4Diacetone Alcohol4Dibenzyl Ether4
Dibutyl Phthalate4Dichloro-Butane4Diesel Oil4
Diethylamine4Diethylamine Glycol4Dimethyl Formamide4
Dimethyl Phthalate4Dioxane4Diphenyl4
Dow Corning 5504Dow Guard0Dowtherm A4
Elco 28 Lubricant0Epoxy Resins0Ethane4
Ethanol4Ethyl Acetoacetate0Ethyl Alcohol4
Ethyl Benzene4Ethyl Benzoate4Ethyl Cellulose4
Ethyl Chloride4Ethyl Chlorocarbonate4Ethyl Diamine4
Ethyl Ether4Ethyl Formate4Ethyl Hexanol4
Ethyl Mercaptan4Ethyl Oxalate4Ethyl Pentachlorobenzene4
Ethyl Silicate4Ethylene4Ethylene Dichloride4
Ethylene Glycol4Ethylene Oxide4Ethylene Trichloride4
Formaldehyde0Freon 11 (M)4Freon 1124
Freon 1134Freon 1144Freon 114B24
Freon 124Freon 134Freon 214
Freon 224Freon 314Freon 324
Freon 502 (F22+F316)0Freon C3184FREON R134A0
Freon TF4Fuel Oil4Furan4
Furfural4Furfuryl Alcohol4Gallic Acid4
Gasoline, Automotive4Gelatine4Glucose4
Glycerin4Glycol, General4Grease, Petroleum Base4
Helium4Heptane4Hexane4
Hexyl Alcohol4Hydraulic Oil, Petroleum Base4Hydrazine4
Hydrobromic Acid0Hydrobromic Acid, Gas4Hydrochloric Acid0
Hydrocyanic Acid4Hydrofluoric Acid4Hydrogen Gas4
Hydrogen Peroxide0Hydroquinone4Iodine4
Iso Octane4Isobutyl Alcohol4Isopropanol4
Isopropyl Acetate4Isopropyl Chloride4Isopropyl Ether4
JP 3 MIL-J56244JP 4 MIL-J56244JP 5 MIL-J56244
JP 6 MIL-J56240Kerosene4Lacquer Solvents4
Lacquers4Lard, Animal Fat4Lindol, Hydraulic Fluid (Phosphate Ester Type)4
Linoleic Acid4Linsed Oil4Liquefied Petroleum Gas (LPG)4
Lubricating Oils, Petroleum Base4Lye4Malathion0
Maleic Acid4Mercuric Chloride4Mercury4
Methane4Methanol4Methyl Acetate4
Methyl Acrylate4Methyl Alcohol4Methyl Bromide4
Methyl Butyl Ketone4Methyl Cellosolve4Methyl Chloride4
Methyl Ether4Methyl Ethyl Ketone (MEK)4Methyl Isobutyl Ketone (MIBK)4
Methyl Mercaptan4Methyl Methacrylate4Methyl Oleate4
Methyl Propyl Salicylate4Methylacrylic Acid4Methylene Chloride4
MIL-F-25558 (RJ-1)0MIL-F-256560MIL-G-257600
MIL-H-56060MIL-H-70830MIL-J 5624, JP-3, JP-4, JP-54
MIL-L-256810MIL-R-25576 (RP-1)0MIL-S-3136, Type 1 Fuel0
MIL-S-810870Milk4Mineral Oils2
Monovinyl Acetate4N-Hexaldehyde1N-Octane4
N-Pentane0Naphtha4Naphthalene4
Naphthalenic4Natural Gas4Neatsfoot Oil4
Nitric Acid4Nitrobenzene4Nitroethane4
Nitrogen Tetroxide4Nitrogen, Gas4Nitromethane4
Nitropropane4Octyl Alcohol4Oleic Acid4
Oleum (Fuming Sulfuric Acid)4Oronite 82000Oxalic Acid0
Oxygen, 200-400F4Oxygen, Cold4Ozone0
Peanut Oil4Petroleum Oil4Phenol0
Phenylhydrazine4Phosphoric Acid4Phosphoric Trichloride4
Pine Oil4Potassium Nitrate4Potassium Sulfate1
Producer Gas3Propane4Propanol1
Propyl Acetate1Propyl Alcohol4Propylene4
Propylene Oxide4Pydraul, 10E4Pydraul, 230C, 312F, 540C4
Pydraul, 30E, 50E, 65E, 90E4Pyranol, Transformer Oil0Pyrogard 42, 43, 53, 55 (Phosphate Ester)4
Radiation4Rapeseed Oil4Red Oil4
RJ-1 (MIL-F-25558)0RP-1 (MIL-R-25576)0Sea Water4
Silicone Grease4Silicone Oils4Silver Nitrate4
Skydrol 5004Sodium Bicarbonate4Sodium Carbonate4
Sodium Chloride4Sodium Hydroxide0Soyabean Oil4
Steam to 350F4Stearic Acid4Stoddard Solvent4
Styrene Monomer4Sucrose Solutions4Sulfur Chloride3
Sulfur Dioxide Gas, Dry4Sulfur Dioxide Gas, Wet4Sulfur Dioxide, Liquefied Under Pressure0
Sulfur Hexafluoride4Sulfur Trioxide4Sulfuric Acid (Concentrated)4
Sulfurous Acid4Tannic Acid4Tartaric Acid4
Tertiary Butyl Alcohol4Tertiary Butyl Mercaptan4Tetrabromoethane0
Tetrabutyl Titanate4Tetrachloroethane4Tetrachloroethylene4
Tetraethyl Lead4Tetrahydrofuran4Tetralin4
Toluene4Transmission Fluid, Type A4Triethanolamine4
Turbine Oil4Turpentine4Varnish4
Vinegar4VV-H-9100Wagner 21B Brake Fluid4
Water, Fresh4Whiskey4White Pine Tar4
Xylene4

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