O

O.D. AND OD– The outside diameter of a pipe or any cylinder is exactly what it sounds like – the distance from one outside edge of the pipe to the opposite outside edge, measuring straight across the face of the pipe or across a cross-section that runs perpendicular to the pipe’s long axis.

If you know the radius of the circle, double it to get the diameter. The radius is the distance from the center of the circle to its edge. If the radius of the circle is 4 cm, then the diameter of the circle is 4 cm x 2, or 8 cm. If you know the circumference of the circle, divide it by π to get the diameter.

Tube is measured by outside diameter, pipe is measured by inside diameter. There is often confusion as to which size die the customer actually needs – Pipe Size or Tubing Size. Keep in mind that pipe size refers to a nominal – not actual – inside pipe diameter.

The formula to find the diameter states the relationship between the diameter and the radius. The diameter is made up of two segments that are each a radius. Therefore, the formula is: Diameter = 2 * the measurement of the radius. You can abbreviate this formula as d=2r.

OS & D HOSE- Scuffs and tears to the cover of 8″ OS&D (Oil Suction & Discharge) hoses.

Measure the distance across the opening in the paper tube with a ruler. This measurement equals the diameter of the inside of your garden hose. Standard sizes include one-half inch, five-eighths inch, three-quarter inch and 1 inch.

ODORANT– an odorous substance especially : one added to a dangerous odorless substance to warn of its presence.

OIL BLACK MASTERBATCH – A rubber (generally SBR) masterbatch containing petroleum oil and carbon black, both added to the SBR latex prior to coagulation.

OIL MASTERBATCH– A masterbatch is a form of material (compounding ingredients, fillers, oil etc) pre-dispersed in a suitable carrier (rubber or plastic) to minimise the problems of handling during mixing (to ease the incorporation of filler at very high loading, minimise pollution and flying of fine particle size fillers).

Masterbatch is a concentrated mixture of pigments and/or additives encapsulated during a heat process into a carrier resin which is then cooled and cut into a granular shape. Masterbatch allows the processor to color raw polymer economically during the plastics process.

A masterbatch for a rubber formulation consists of a mixture of rubber and one or more additives, such as rubber chemicals or carbon black, Insoluble Sulfur, present in high concentrations.

Red, blue, yellow is the three primary color, and other colors can synthesize through these three colours.

OIL RESISTANCE– Oil resistance is a special case of fluid resistance. Broadly defined, oil resistance is the ability of a rubber product to perform its intended function while in contact with oil. … The so-called oil-resistant elastomers absorb some oil, especially at elevated temperature, but only a limited amount.

Nitrile (Buna N) – This type of rubber offers very good oil resistance and can be used for a good variety of refined oils. Nitrile is the most commonly used material for sealing oil.

Nitrile is valuable for its superior chemical, abrasion, and water resistance. Neoprene, on the other hand, is prized for its particular resistance to weather and impact. Due to their particular properties, each material is used for a different range of products.

OLEFIN– Olefin, also called alkene, compound made up of hydrogen and carbon that contains one or more pairs of carbon atoms linked by a double bond. Olefins are examples of unsaturated hydrocarbons (compounds that contain only hydrogen and carbon and at least one double or triple bond).

Olefin is another name for polypropylene fiber.

Chemically speaking, polypropylene sounds like a complicated process, but is in fact a greener fabric than cotton, wool, silk, or rayon. Olefin, or PP, is a synthetic based polypropylene fabric that was first created in Italy in 1957.

Olefin is a very sturdy fabric made from polypropylene which is popular for outdoor furniture cushions. Some Olefin fabrics are waterproof and can be wiped down if anything is spilt on them. … OLEFIN fabrics are the best wearing of all outdoor fabrics. Like acrylics, they are fade and stain resistant and dry quickly.

Olefin can be washed in cold or warm water. Like most synthetic fibers, high temperatures in the washer can cause olefin fibers to melt and stick together, shrink, or deform. Always use cool or warm water when washing and cold water in the rinse cycle.

How is it cleaned? Most stains can be easily removed by dabbing the stain with lukewarm water and a mild detergent. You can use bleach on Olefin fabric if necessary. If you wash Olefin, line drying is the best option.

OPEN CELL– Open-cell sponge rubber has distinct cells that are interconnected to neighboring cells. There are no discreet and separated individual cell walls. Rather, this network of elastic rubber tunnels allows air to easily re-inflate the sponge article once a deforming force is removed, enabling the article to rapidly regain its original physical form and dimension.

Due to this resilience and the ability of the cell structure to rapidly return to its original uncompressed state, open-cell rubber can be an ideal choice for sound damping and cushioning applications.

OPEN STEAM CURE– Steam curing of concrete is the method of curing the concrete elements in water vapor. This curing is performed either under atmospheric pressure or high-pressure steam.

OPTIMUM CURE– Optimum cure time (t90), which as stated earlier, is the. time required for the torque to reach 90% of the maximum. achievable torque (T90) and relates to the time necessary for the. cured rubber to achieve optimal properties.7 The last stage can.

• tc50 (50 % cure time). It is the moment when 50% cross-linking has been reached.
• tc90 (90% cure time). It is the moment in which 90% cross-linking has been reached.

The cure rate index (CRI) is a measurement of the cure rate based on the differences between the optimum cure time (t90) and incipient scorch time (ts2) [6]. The CRI of the NR compound with ALK was higher than that of the NR compound without ALK.

ORANGE PEEL– Orange peel is a coating characteristic resulting in a surface appearance like the skin of an orange. You can see Orange peel on high gloss surfaces as a wavy pattern of light and dark areas. Depending on the slope of the structure element, the light is reflected in various directions.

Orange peel is a certain kind of finish that may develop on painted and cast surfaces. The texture resembles the surface of the skin of an orange, hence the name “Orange peel”. Gloss paint sprayed on a smooth surface (such as the body of a car) should also dry into a smooth surface.

Here are some adjectives for orange-peel: always more or less, always more, trodden, candid, chopped, stale, muddy, steep, eternal, more or less, bitter, hideous, brown, fresh, dirty, whole, thin, less, more. You can get the definitions of these adjectives by clicking on them.

Generally speaking orange peel texture is most prevalent in the clear coat, but at the OEM level, it is likely in the primer and base coats as well. Modern, slow-drying, environmentally friendly water-based (borne) paints are slow drying, which tends to allow the paint to flow as it dries, increasing the texture.

ORGANIC – Organic chemistry is the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds, which include not only hydrocarbons but also compounds with any number of other elements, including hydrogen (most compounds contain at least one carbon–hydrogen bond), nitrogen, oxygen.

ORGANOSOL– Organosols are industrial coatings where resins such as polyvinyl chloride (PVC) are suspended or dispersed in an organic fluid. These coatings are not dissolved in the organic fluid but rather suspended in it. The dispersion technique is helpful because it allows the organosol coatings consisting of higher molecular weight insoluble resins to be used without using expensive solvents.

Organosol coatings are available in a wide range of flow characteristics and consequently may be formulated for application by any of the conventional techniques. In these coatings, the fluid or the dispersant contains plasticizers along with a blend of volatile dilutents that help to impart organosols with the necessary fluidity, physical properties and speed of fusion.
When applied, organosols are generally limited to a thickness of 10 to 12 mils per coat. This is due to the substantial quantities of volatile diluents present. Rapid heating results in solvent blistering, whereas the reverse causes a mud-cracking effect.
Organosol coatings can be applied by the following methods:

• Spread coating
• Strand coating
• Dip coating
• Spray coating

O-RING– O rings are used to block a path which may otherwise allow a liquid or a gas to escape. The o ring is placed into a groove to secure them in place, and then compressed between two surfaces.

O-rings are probably the most common fluid power seals. … O-rings seal by mechanical deformation that creates a barrier to a fluid’s potential leak path between two closely mated surfaces. O-rings are typically installed in a groove that’s machined or molded in one of the surfaces to be sealed.

To measure the outside diameter, use a ruler to measure from one outer edge to the other of the o-ring. You can determine the third diameter of the O-ring with 2 diameters using the following equation: Outside Diameter (OD) = Inside Diameter + (2 x Cross Section). Inside Diameter (ID) = OD – (2 x Cross Section).

To provide an effective seal, the O-ring’s inside diameter (I.D.) must be smaller than the piston groove diameter, so that the O-ring is slightly stretched, fitting snugly in the groove. This stretch should be between 1%-5% with 2% as the ideal in most applications. A stretch greater than 5% is not recommended.

Size	UK Size	Circumference (mm)
Large	N	54.0
X Large	O	55.2
X Large	P	56.5
X Large	Q	57.6

 

OVEN-AGING TEST – Test Procedure: The samples are placed in an aging oven. The temperature and duration are specified by the customer. The specimens are removed and tested

Oven ageing is a technique used to simulate the ageing process, artificially speeding it up by generating specific temperature conditions.

The Accelerate Aging test simulates real-time aging using elevated temperatures to artificially speed up the aging process. This test enables manufacturers to get their product to market faster. … Additional testing is performed after aging to access the packaging and/or product performance.

OVERCURE–
An overcure is a condition in which the parameters of a curing process were exceeded. Generally, the term implies the occurrence of defects in the polymeric material that was overcured. As curing is a hardening process, overcurring may result in a material that is over hardened.

OVERFLOW– Also known as flashing, is excess material attached to a molded, forged, or cast product, which must usually be removed. This is typically caused by leakage of the material between the two surfaces of a mold (beginning along the parting line) or between the base material and the mold in the case of overmolding.

Flash is a molding defect that occurs when some molten plastic escapes from the mold cavity. Typical routes for escape are through the parting line or ejector pin locations. This extrusion cools and remains attached to the finished product.

The raw material is heated in the mould until pliable while the mould is closed for a specified period. Upon removal it is quite common that the moulded product to contain excess materials, normally called flashing, which has extruded while being heated and compressed in the mould.

OXIDATION– The term oxidation was originally used to describe reactions in which an element combines with oxygen. Example: The reaction between magnesium metal and oxygen to form magnesium oxide involves the oxidation of magnesium. … And, each O2 molecule gains four electrons to form a pair of O2- ions.

The iron metal is oxidized to form the iron oxide known as rust. Meanwhile, oxygen is reduced. Another example of oxidation where an element combines with oxygen is the reaction between magnesium metal and oxygen to form magnesium oxide.

Oxidation means the process of losing of electrons by any substance. … Oxidation also means the process of addition of oxygen. Since oxygen is being added to the compound, so the process is called oxidation.

OXYGEN BOMB– Oxygen bomb calorimeters measure the heat of chemical reactions or physical changes. … In an oxygen bomb calorimeter, the sample is loaded in the reaction chamber (called the bomb) along with oxygen; this is submerged in water within an insulating container.

The bomb calorimeter is the most common device for measuring the heat of combustion or calorific value of a material. … The combustion process is initiated inside an atmosphere of oxygen in a constant volume container, the bomb, which is a vessel built to withstand high pressures.

A bomb calorimeter is a type of constant-volume calorimeter used in measuring the heat of combustion of a particular reaction. Bomb calorimeters have to withstand the large pressure within the calorimeter as the reaction is being measured.

OZONE (O3) – Ozone, O3, is a form of oxygen; a blue gas with a pungent odor noticeable when gas is formed by an electrical discharge. … Ozone (O3) is a triatomic molecule, consisting of three oxygen atoms. Ozone in the upper atmosphere protects living organisms by preventing ultraviolet rays from reaching the Earth’s surface.

Stratospheric ozone is “good” because it protects living things from ultraviolet radiation from the sun. … Called stratospheric ozone, good ozone occurs naturally in the upper atmosphere, where it forms a protective layer that shields us from the sun’s harmful ultraviolet rays.

Opening – Any excavation in or into a mine.

Open end pillaring – A method of mining pillars in which no stump is left; the pockets driven are open on the gob side and the roof is supported by timber.

Operator – The person, company, corporation working a mine, or the individual at the controls of a machine.
Outby; outbye – Nearer to the shaft, and hence farther from the working face. Toward the mine entrance. The opposite of inby.

Outcrop – Coal that appears at or near the surface.

Overburden – Layers of soil and rock covering a coal seam. Overburden is removed prior to surface mining and replaced after the coal is taken from the seam.

Overcast (undercast) – Enclosed airway which permits one air current to pass over (under) another without interruption.