Glossary of Terms

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3A Symbol - Introduced in 1956, the 3A Symbol is a registered trademark used to identify equipment that meets 3A Sanitary Standards for design and fabrication. The 3A Symbol on dairy and food equipment serves three important purposes:

1. Assures processors that equipment conforms to sanitary standards2. Provides accepted criteria to equipment manufacturers for sanitary design3. Establishes guidelines for uniform evaluation and compliance by sanitarians

ABS - (Acrylicnitrile-butadiene-styrene) a thermoplastic resin with an excellent resistance to acids,bases, salts and some solvents. It is heat resistant to 230°F.

ANSI - American National Standards Institute, Inc. (www.ansi.org)

ASME - American Society of Mechanical Engineers (www.asme.org)

ASTM - American Society for Testing and Materials (www.astm.org)

Acme Thread - A flat grooved helical ridge on a nut or bolt. This typically has a 29° included angle. Used on bevel seat and John Perry fittings

Anneal - Stress relief of stainless steel, a heat treatment to remove the stresses generated in forming and welding operations. This heat treatment is best done under controlled atmosphere or vacuum to maintain the mill finish. The fittings are not quenched, as in solution annealing; this would reintroduce residual stresses. Done correctly, parts are processed to provide minimum residual stresses and full corrosion resistance.

Automatic Weld - Also know as Orbital Welding. Automatic welding whereby the arc is rotated mechanically through 3600 (1800 in double up welding) around a static work piece, an object such as a pipe, in a continuous process, with or without filler material. The process eliminates the constant adjusting of controls by the welder/operator. Equipment controls joint alignment by means of automatic sensing devices.

Bevel Seat Ferrules - A set of plain (male) and externally threaded (female) bushings with matchingbevel angles that produce a leak-proof seal when connected with a hex union nut. The threads used are Acme form.

Bioprocessing - Specific process that uses complete living cells or their components (e.g. bacteria, enzymes, chloroplasts) to obtain desired products.

Borescope - An optional device consisting of a rigid or flexible tube with an experience on one end, an objective lens on the other, linked together by a relay optical system in between. Used for the inspection of difficult to access locations.

Bright Anneal - Annealing in a protective medium to prevent discoloration of the surface.

Buna - Synthetic rubber, a copolymer of acrylonitrile and butadiene

Burst Pressure - The pressure at which rupture occurs.

Glossary of Terms

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Clamp - A device used to join mechanical parts, fittings, ensuring a quick leak-proof connection andenabling easy take down.

Clean-in-Place (CIP) - A method of cleaning the interior surfaces of pipes, vessels, process equipment, typically with acid, caustic or a combination of both, without disassembly.

Cold Flow - Continued deformation or movement of rubber or PTFE under stress. The new set is notreversible.

Compendial Water - Water that complies with USP and/or other acknowledged body related to the quality, manufacture or distribution of high purity water.

Compression Set - The deformation that remains in rubber or PTFE after it has been subjected to and released from stress such as a clamp. The longer the stress is maintained the more definitive the deformation.

Dead Leg - An area of entrapment in a vessel or piping run that could lead to contamination of theproduct.

Durometer - An instrument for measuring the hardness of rubber by resistance to penetration

Durometer Hardness - A numerical value which indicates the resistance to indentation of the blunt indentor of the durometer.

EPDM - Ethylene propylene diene monomer, a synthetic rubber.

Elastomer - Any of various elastic substances resembling rubber.

Electropolishing - A controlled electrochemical process utilizing an acid electrolyte, DC current, anode and cathode to bring chrome up to the surface, depositing a few angstrom thick layer on the surface of the stainless steel. This improves both the surface finish and the corrosion resistance.

Encapsulation - The enclosing of material by an encapsulant for protective purposes. In a ball valve the ball is encased in PTFE, preventing the material flowing through the valve from getting behind the ball causing contamination problems.

Fixture Mark - An area on an electropolished component where the electrical connection was made for processing the component.

Glossary of Terms

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Raised Face (RFTHD) Flat Face (FFTHD)

Raised Face (RFBLD) (Hi-Hub) Raised Face Plate

Raised Face (RFSO) Plate Flat Face (FFSO)

Flange Types

Blind Flanges

Slip-On-Flanges

Do not have a bore and are used to shut off a piping system or vessel opening. Its design permits easy access to vessel or piping system for inspection purposes. It can be supplied with or without hubs at the manufacturer’s option. In terms of internal pressure and bolt loading, blind flanges, especially in the larger sizes, are the most highly stressed flange types.

Are slipped over the pipe and then welded from both inside and outside to provide sufficient strength and prevent leakage. This flange is used instead of weld necks by many users because of its lower cost and also the fact that it requires less accuracy when cutting pipe to length. Slip-On flanges cannot be used with many types of fittings as the fitting ends are not “straight” and thus the flange cannot slip over the fitting sufficiently to permit welding.

Threaded Flanges

Used for special circumstances with their main advantage being that they can be attached to the pipe without welding. Sometimes a seal weld is also used in conjunction with the threaded connection. Although available in most sizes andpressure rating, threaded flanges today are used almost exclusively in smaller pipe sizes. Threaded flanges are not suitable for piping with thin wall thicknesses because cutting a thread on the pipe is not possible.

Glossary of Terms

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Lap Joint Flange

Nearly identical to a slip-on flange, but having a radius at the intersection of the bore and the flange face to accommodate a lap stub end. These flanges slip over the pipe and are not otherwise welded or fastened to it. Bolting pressure is transmitted to the gasket by the pressure of the flange against the back of the pipe lap (stub-end). The face on the stub-end forms the gasket face of the flange. Lap-Joint flanges do not have raised faces and a single connection requires both lap-joint flange and a pipe stub-end. They are best used where sections of piping systems need to be dismantled quickly and easily for inspection or replacement.

Socket Weld Flange

Similar to a slip-on flange in outline, but with a bore that is counter-bored to accept pipe. The diameter of the remaining bore is the same as the inside diameter of the pipe. A fillet weld around the hub of the flange attached the flange to the pipe. An optional interval weld may be applied in high stress applications. Its biggest use is in high pressure systems such as hydraulic and steam lines.

Weld-Neck Flanges

Also known as a high-hub flange or a tapered hub flange, weld-neck flanges are designed to be joined to a piping system by butt-welding. They are expensive because if the long neck, but are preferred when piping is subject to high stresses. The neck, or hub, helps to transmit environmental stress at the flange with the pipe to which it is welded to. The gradual transition of thick-ness from the base of the hub to the wall thickness at the butt weld provides important reinforcement of the flange. Turbulence and erosion are reduced due to the matching bore size of the pipe and flange. These flanges are bored to match the ID of the mating pipe so there is no restriction of flow.

Flange Types (cont’d)

Glossary of Terms

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Flange Facing

Ring Type Joint (RTJ)

Ring-Type Joint (RTJ): Ring-Type Joint flanges are typically used in high pressure (Class 600 and higher rating) and hightemperature services (above 800°F or 427°C).

RTJ flanges have grooves cut into their faces. This raised face does not serve as any part of the sealing system. The flanges seal when tightened bolts compress the gasket between the flanges into the grooves, deforming (or “coining”) the gasket to make intimate contact inside the grooves creating a metal to metal seal.

An RTJ flange may have a raised face with a ring groove machined into it. For RTJ flanges that seal with ring gaskets, the raised faces of the connected and tightened flanges may contact each other. In this case, the compressed gasket will not bear additional load beyond the bolt tension, vibration and movement cannot further crush the gasket and lessen the connecting tension.

RTJ flanges are considered to be the most efficient flanges for use in pipeline design. Rather than using a gasket between the connecting flanges, RTJ flanges have a deep groove in a ring shared around the face. Ring type gaskets must be used on this type of flange. Ring-Type Joint gaskets are metallic sealing rings, suitable for high-pressure and high-temperature applications.

Ring Type Gasket

Tongue & Groove (T&G)

Tongue & Groove (T&G): Tongue & Groove flanges must be matched properly. One flange face has a raised ring (the Tongue) machined into the flange face while the mating flange has a matching depression (the Groove) machined into its face. These facings are commonly found on pump covers and valve bonnets.

T&G facings are standardized n both large and small types. They differ from male and female in that the inside diameters of the tongue and groove do not extend into the flange base, thus retaining the casket on its inner and outer diameter. T&G joints also have an advantage in that they are self-aligning and act as a reservoir for the adhesive. The scarf joint keeps the axis of loading in line with the joint and does not require a major machining operation.

Glossary of Terms

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Raised Face (RF)

Raised Face (RF): The Raised Face type is the most common flange type in process plant operations and is easy to identify. The gasket is raised 1/16” to ¼” above the bolt circle face. This face type allows the use of a wide combination of gasket designs,including flat ring sheet types and metallic composites such as spiral wound and double jacketed types. The purpose of an RF flange is to concentrate more pressure on a smaller gasket area, increasing the pressure containment capability of the joint.

Flat Face (FF)

Flat Face (FF): The Flat Face (full face) flange has a gasket surface in the same plane as the bolting circle face. Applications using flat face flanges are frequently those in which the mating flange or flanged fitting is made from a casting.

Flat face flanges should never be bolted to a raised face flange. When connecting flat face cast iron flange to carbon steel flanges, the raised face on the carbon steel flange must be removed, and a full face gasket is required. Flat face flanges are used on pump facings or on fiberglass flanges (where the torque of compressing the gasket will damage the flange body) and on cast iron flanges sometimes found on mechanical equipment (that can cause complications due to the brittle nature of cast iron.) Forged steel flat face flanges are often found with 150# and 300# ratings.

Male & Female (M&F)

Male & Female (M&F): This type of flange also must be matched. One flange face has an area that extends beyond the normal flange face (the Male) while the other flange or mating flange has a matching depression (the Female) machined into its face. Cus-tom male and female facings are commonly found on the heat exchanger shell to channel and cover flanges. The female face is 3/16” deep and the male face it ¼” high, and both are smooth finished. The outer diameter of the female efface acts to locate and retain the gasket.

Advantages include better sealing properties, more precise location and exact compression of the sealing material, utilization of other more suitable sealing and specialized sealing materials. Disadvantages include the fact that normal RF flanges are far more common and readily available with regard to valves, flanges and sealing materials. M&F flange connections require very rigid rules when designing piping systems to ensure proper mating.

Flange Facing (cont’d)

Glossary of Terms

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Flow Coefficient (Cv) - Cv the flow rate in U.S. gallons of water (at 60°F) that will pass through thevalve in one minute with a differential pressure loss across the valve of 1 PSI.

Ferrule - A fitting designed for welding to the end of tubing. Two ferrules and a gasket make a leak-proofconnection when used with the appropriate complimentary clamps. Ferrules come in a variety of lengths. John Perry and Bevel Seat style fittings also require ferrules to make connections.

Fitting - A small part of an apparatus (may be detachable).

Fluorocarbon - Synthetic rubber and fluoropolymer elastomer known as FKM.

Friction Loss - The part of the total loss that occurs as the fluid flows through straight pipe.

Full Penetration Weld - A weld joint where the depth of the weld extends from its face into the weld joint so that the joint is fully fused.

Gasket - A static seal which fills the space between two or more mating surfaces, generally to prevent leakage from or into the joined objects while under compression.

Heat Number - The identification number that is stamped on a material plate after it is removed from the ladle and rolled at a steel mill.

Hex Union Nut - An internally acme-threaded six-sided connector used to assemble bevel seat fittings.

Hydrotest - A pressure test of vessels, piping or components performed by pressurizing the internal volume with water at a pressure defined by applicable code.

Hygienic - Term used to describe equipment and piping systems that, by their design, construction and operation provide for cleanliness so that the products produced will not adversely affect human or animal health.

ISO5211 - International standard for actuator and valve interface.

Internal Expansion (IX) - A plug (or bullet) is pulled through a stem or a set of blades (fingers) increase the stem ID to the plug OD or a predetermined setting when using expansion blades (fingers). This forces the stem serrations into the hose tube and the hose cover into the serrations of the ferrule.

Laminar Flow - The smooth flow of a viscous liquid through a tube or pipe. In that case, the velocity of flow varies from zeroat the walls to a maximum along the centerline of the vessel.

Lay - One of the three components of surface finish. Lay is the direction of the predominant surfacepattern ordinarily determined by the production method used.

Glossary of Terms

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Manual Welding - Welding in whpressure of the media flowing into the valve against which the valve will have to close.

Maximum-Shut-Off Pressure - The pressure of the media flowing into the valve against which the valve will have to close.

Maximum Working Temperature/Pressure - The temperature/pressure at which the system iscapable of operating for a sustained period of time.

Mechanical Seal - A device used for sealing fluids with rotating shafts.

Media - The material flowing through the tubing or piping system.

Modulating Service - Proportional positioning of a valve between the open and closed position. Used for flow control processes.

MTR - Material Test Report. A heat number is required to get an MTR.

Neoprene - Synthetic rubber, chemically and structurally similar to natural rubber.

Nominal Size - A dimensional value assigned for the purpose of convenient designation. Used for pipe sizes.

On-Off Service - When the valve is being used to start or stop flow by being cycled to the full open or full closed position.

Operating Pressure - The pressure at which system functions. Also known as working pressure.

Orbital Welding - Also know as Orbital Welding. Automatic welding whereby the arc is rotated mechanically through 3600 (1800 in double up welding) around a static work piece, an object such as a pipe, in a continuous process, with or without filler material. The process eliminates the constant adjusting of controls by the welder/operator. Equipment controls joint alignment by means of automatic sensing devices.

O-ring - A static seal of circular cross section.

Passivation - The removal of free iron from the surface or stainless steel by means of a chemical dissolution, usally by acid which enhances the formation of the passive layer.

Pipe - Like metal tubing, pipe conveys a fluid or other media. Unlike tubing, pipe does not have a true OD. For example, 2” pipe has a nominal OD of 2.375”. Wall thickness is in Schedules ranging from 5 up to XXH.

Polish - To make smooth and shiny by rubbing. Fittings may be machine polished to 180 grit finish. Polish is ID, OD, or both per customer request.

Glossary of Terms

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Polypropylene - A lightweight synthetic plastic

Pressure - The force per unit area applied on a surface in a direction perpendicular to that surface.

Product Contact Surface - Any surface that contacts raw materials, process materials and/or product.

Profilometer - A measuring instrument used to measure a surface’s profile, in order to quantify its roughness, typically expressed in Ra.

PSI - Pounds per square inch

PSIG - Pounds per square inch gauge

PTFE - Tetrafluoroethylene is a high performance thermo plastic fluoropolymer that has excellentdielectric strength, chemical and temperature resistance.

Ra - Roughness Average: the log of the arithmetic mean of the surface profile. The lower (samller) the number, the smoother the surface.

Santoprene - A thermoplastic elastomer, a rubber-like material that complies to FDA requirements

Scale - Also known as Mill Scale, is a flaky surface that forms on hot-rolled steel consisting of iron oxides. Usually bluish-black in color, scale is typically less than 0.1 mm thick and protects the steel surface from atmpospheric corrosion. Scale is viewed as a nuisance because once it starts breaking and cracking, the newly exposed surface will corrode at an accelerated rate.

Service Temperature - The maximum and minimum temperature of the media in a system.

Silicone - Dimethyl silicone, a synthetic rubber

Sintering - Heat process in which powdered metal particles are heated to near melting point, fusing the metal granules together.

Steam-in-Place (SIP) - The use of steam to sterilize a piece of equipment without the use of an autoclave.

Stem Torque - The force required at the valve stem to open or close the valve against system pressure and service conditions.

Sterile - Free from living organisms.

Surface Finish - The description of the surface expressed in Ra, usually expressed in micro-inches (µ-Inches)

Supply Pressure - The plant air supply pressure available to operate a pneumatic actuator.

Glossary of Terms

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Surface Finish - Sheet

#1 FinishA #1 finish has a rough, dull, and non-uniform appearance. There may be shiny spots where surface imperfections were removed by grinding. It is generally used in industrial applications, such as equipment for elevated temperature service. Produced by rolling stainless steel that has been heated prior to rolling (hot-rolling). This is followed by a heat treatment that produces a uniform microstructure (annealing) and ensures that the stainless steel will meet mechanical property requirements. After these processing steps, the surface has a dark non-uniform appearance called “scale”. Surface chromium has been lost during the previous processing steps, and without removal of the scale, the stainless steel would not provide the expected level of corrosion resistance. Chemical removal of this scale is called pickling or descaling, and it is the final processing step.

#2B FinishA bright cold rolled finish commonly produced in the same manner as #2D, except that the final light cold rolling pass is done using polished rolls. This produces a more reflective finish that resembles a cloudy mirror. Finish reflectivity can vary from manufacturer to manufacturer and coil to coil with some coils looking quite mirror-like and others being fairly dull. #2B is a general purpose cold rolled finish commonly used for all but exceptionally difficult deep drawing applications. It is more readily polished to high luster than a #1 or #2D finish.

#2D FinishA uniform, dull silver gray finish that is applied to thinner coils whose thickness has been reduced by cold rolling. After rolling, the coil is heat treated to produce a uniform microstructure (annealing) and to meet mechanical property requirements. Pickling or descaling is necessary after heat treatment to remove the chromium depleted dark surface layer and restore corrosion resistance. Pickling can be the final step in production of this finish, but, when finish uniformity and/or flatness are important, there is a subsequent final light cold rolling pass (skin pass) through dull rolls. A #2D finish ispreferred for deep drawing components because it retains lubricants well. It is used as a substrate when a painted finish is desired because it provides excellent paint adherence.

Bright Annealed (BA or 2BA)Produced by heat-treating (annealing) in a controlled atmosphere furnace. It has a mirror like appearance but may have some cloudiness and other imperfections. A finish that is designated “BA” has only been bright annealed. A finish that is designated “2BA” has been bright annealed and then passed between highly polished rolls. A minimal amount of roll pressure (skin pass) is applied. The process improves flatness and finish uniformity but does not significantly decrease thickness. Bright annealed stainless is sometimes buffed to attain a more mirror-like finish. It is often specified for applications where a highly reflective surface is desired.

#3 FinishAlso known as grinding, roughing or rough grinding. These finishes are coarse in nature andusually are a preliminary finish applied before manufacturing. An example would be grinding gates off of castings, deburring or removing excess weld material. It is coarse in appearance and applied by using 36-100 grit abrasive. When the finish is specified as #3, the material is polished to a uniform 60-80 grit.

Glossary of Terms

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#4 Architectural FinishAlso known as brushed, directional or satin finish. A #4 Architectural finish is characterized by fine polishing grit lines that are uniform and directional in appearance. It is produced by polishing the metal with a 120-180 grit belt or wheel finish and then softened with an 80-120 grit greaseless compound or a medium non-woven abrasive belt or pad.

#4 Dairy or Sanitary FinishThis finish is commonly used for the medical and food industry and almost exclusively used on stainless steel. This finish is much finer than a #4 Architectural finish. This finish enhances the physical appearance of the metal as well as increases the sanitary benefits. One takes great care to remove any surface defects in the metal, like pits, that could allow bacteria to grow. A #4 diary or sanitary finish is produced by polishing with a 180-240 grit belt or wheel finish softened with 120-240 grit greaseless compound or a fine non-woven abrasive belt or pad.

#6 FinishAlso known as a fine satin finish. This finish is produced by polishing with a 220-280 grit belt orwheel softened with a 220-230 greaseless compound or very fine non-woven abrasive belt or pad. Polishing lines will be soft and less reflective than a #4 Architectural finish.

#7 FinishA #7 finish is produced by polishing with a 280-320 belt or wheel and sisal buffing with a cut and color compound. This is a semi-bright finish that will still have some polishing lines but they will be very dull. Carbon steel and iron are commonly polished to a #7 finish before chrome plating. A #7 finish can be made bright by color buffing with coloring compound and a cotton buff. This iscommonly applied to keep polishing costs down when a part needs to be shiny but not flawless.

#8 FinishAlso known as a mirror finish. This finish is produced by polishing with at least a 320 grit belt or wheel finish. Care will be taken in making sure all surface defects are removed. The part is sisal buffed and then color buffed to achieve a mirror finish. The quality of this finish is dependent on the quality of the metal being polished. Some alloys of steel and aluminum cannot be brought to a mirror finish. Castings that have slag or pits will also be difficult, if not impossible, to polish to a #8.

Surface Finish - XXX

#3 Finish Used on stainless steel tubing, only the ID is polished to sanitary standards. The OD is unpolished.

#4 Dairy Finish Used on any surface, stainless steel is polished to sanitary standards, with 180 grit abrasives.

#5 FinishUsed on stainless steel tubing, only the OD is polished. The ID is unpolished.

#7 FinishUsed on stainless steel tubing polished to sanitary standards inside and outside.

3A FinishProduct surface finish equivalent to 150 grit or better OD, and 180 grit or better ID. A maximum of a 32 microinch (0.8 micron) is indicated.

Glossary of Terms

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Surge - Also known as water hammer. A rapid rise or decrease of internal pressure. Surge conditions occur for various reasons and are not limited to start and stop sequences.

TIG Welding - Also known as Tungsten inert gas welding. TIG welding is a process that uses a non-consumeable Tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by an inert, shielding gas (argon or helium), and a filler metal is normally used.

Torque - A twisting or turning force. Usually measured in inch-pounds (in-lbs) or foot-pounds (ft-lbs)/(force through a distance).

Tube - A hollow cylinder, especially one that conveys a fluid. For sanitary applications a thin wall is implied. Tubing has a true OD dimension, where the wall thickness is expressed as fractional equivalent (i.e. 0.065) or in gauges (i.e. 16 gauge).

Tube Fitting - A length of tubing formed into a usable shape either welded to an apparatus or welded to ferrules for use in an apparatus.

Tubing - A piece or length of tube.

Tumble Polish Surface - A uniform finish applied by vibratory equipment to stainless steel, varying from matte grey to bright, depending on media used. This process may cause work hardening on the surfaces of stainless steel.

Turbulent Flow - Irregular flow that is characterized by tiny whirlpool regions. The velocity of this fluid is definitely not constant at every point.

Validation - Documented evidence that the system does what it purports to do.

Velocity Head (hv) - The energy of a liquid as a result of its motion at some velocity V. It is the equivalent head in feet through which the water would have to fall to acquire the same velocity, or in other words, the head necessary to accelerate the water. Velocity head can be calculated from the following formula:

V2 hv = 2g

Where g = 32.3 ft/second V = liquid velocity in feet per second

The velocity head is usually insignificant and can be ignored in most high head systems. However, it can be a large factor and must be considered in low head systems

Glossary of Terms

Page 13

WOG - Water, Oil, Gas. Pressure rating for valves handling these products. This does not include steam.

Weld Spud - An alternative to NPT half-couplings, welding spuds have a flanged surface area where they are attached (welded) to your tank or vessel and then provide NPT threads to only one side. Welding spuds provide a very low profile compared to a half-coupling.

Welding - Joining two (or more) pieces of material by applying heat to produce a localized union through fusion across the interface. For sanitary fittings, a ferrule is attached to the ends of a tube fitting by TIG welding without the addition of filler metal.

WFI - A classification of compendial water suitable for human injection.

Work (Strain) Hardening - An increase in hardness and strength caused by plastic deformation at temperatures below the annealing ranges.