Midterm Flashcards
the difference between the initial lift-off pressure and the pressure of the fully open position for a relief valve
Accumulation
a device that controls the position of the flow-control element on a control valve by automatically adjusting the position of the valve stem.
Actuator
a valve that operates by admitting fluid flow to the gate or plug and redirecting it 90° out the discharge port
Angle Valve
lubricant used on exposed valve stem threads
Antiseize compound
also known as self-actuating, these valves perform their specific function without external assistance
automatic valve
A valve named for the ball-shaped, movable element in the center of the valve
ball valve
any valve that is intended to block flow; also called an isolation valve. The term generally refers to gate valves
block valve
a bell-shaped dome mounted on the body of a valve, which provides a housing for the flow control element when lifted out of the flow
bonnet
manufacturer information on the body of a valve
bridgewall markings
an adapter threaded to permit joining of pipes with different diameters
bushing
valve characterized by their disc-shaped flow-control element, which pivots from its center
butterfly valve
mechanical valves that prevent reverse flow in piping
check valves
dome shaped element attached to the valve stem which
presses on the flexible diaphragm to restrict flow
compressor (diaphragm valve)
a collection of instruments that work together to automatically control a process; usually consists of a sensing device, a transmitter, a controller, a transducer, and an automatic valve
control loop
automated valves used to regulate and throttle flow; typically provide the final control element of a control loop
control valves
the equipment concerned with controlling the operation of an electrical device
controller
something flexible that serves as a barrier
diaphragm
a valve that uses a flexible membrane to regulate flow
diaphragm valve
a device made of metal or ceramic that fits snugly in the seat of a valve to control flow
disc
the part of a valve that regulates flow; that is, the gate or the disc
flow-control element
liquid and gas forms of matter (not solids).
fluid
the flow-control element of a gate valve.
gate
a valve with a movable metal gate in the path of a process flow
gate valve
a device that places a disc in the path of a process flow
globe valve
attachment to the valve stem used to control the position of the flow-control element of a valve
handwheel
a valve that completely obstructs the path of a fluid and isolates a part of a system.
isolation valve
valve with multiple inlets and/or outlets in specialized piping systems to divert flow direction, allowing fluid sources to be switched.
multiport valve
a type of globe valve that has a needle-shaped element that fits snugly into the seat
needle valve
a type of valve mechanism that has a collar that keeps the stem from moving up and down. You cannot tell if this type of valve is open or closed by looking at it
nonrising stem
a specially designed material used to stop fluid from entering or escaping; packed around the shaft (stem) of a valve, or shaft of a pump
packing
a mechanical device that contains and compresses packing
packing gland
device that uses an airtight cylinder and piston to move or position the stem; it is commonly used with automated gate valves or slide valves
piston actuator
a valve that has a plug-shaped element; used for on/off service
plug valve
valve set to automatically relieve pressure in a closed system at a predetermined set point for liquids
relief valve
a type of valve mechanism in which the stem of the valve rises along with the gate, disk, or globe when opened. You can tell if this type of valve is open or closed by looking at it
rising stem
valve set to automatically relieve pressure in a closed system at a predetermined set point for gases
safety valve
a device that keeps track of the measured condition (e.g., temperature, pressure) and its fluctuations so that when sufficient variation occurs it will originate the signal to change the operation of the system
sensing device
the section of a valve that contains packing
stuffing box
a valve with three ports (one inlet and two outlets) used to divert flow direction
three-way valve
reducing or regulating flow below the maximum output of a valve
throttling
a device that converts variations in a physical quantity, such as pressure or temperature, into an electrical signal, or vice versa
transducer
an electronic device used to generate and send electromagnetic waves carrying messages or signals
transmitter
the flow-control element and seats in a valve
trim
a fluid flow in which the velocity at a given point varies erratically in magnitude and direction. In valves, can cause metal erosion, seat damage, and damage to the flow controlling element
turbulent flow
a device used to stop, start, restrict (throttle), or direct the flow of fluids
valve
the outer casing of most or all of the valve that contains the internal parts or trim
valve body
the total amount of fluid a valve will pass with a given pressure difference when it is fully open
valve capacity
the fixed surface on which a valve controlling element rests or against which it presses
valve seat
a long, slender metal shaft attached to the handwheel and flow-control element of a valve
valve stem
device used to direct air against paddles or vanes, are frequently used on quarter-turn valves
vane actuator
become bent or twisted out of shape. In valves, caused by temperature changes, pipe expansion, or closing a valve too quickly. Leads to valve sticking or seizing
warp
a device used to connect (bolt) piping to industrial equipment
flange
Enhances arc starts and provides a softer arc throughout all ranges, with less puddle turbulence and less spatter
Active Arc Stabilizer
Automatically increases the output amperage at the start of a stick weld, should the start require it. Helps eliminate sticking of the electrode at arc start
Adaptive Hot Start
A cutting process by which metals are melted by the heat of an arc using a carbon electrode. Molten metal is forced away from the cut by a blast of forced air
Air Carbon Arc Cutting (CAC-A)
An electrical current that reverses its direction at regular intervals, such as 60 cycles alternating current (AC), or 60 hertz
Alternating Current (AC)
The measurement of the amount of electricity flowing past a given point in a conductor per second (i.e., current)
Amperage (amps)
The physical gap between the end of the electrode and the base metal. The physical gap causes heat due to resistance of current flow and arc rays
Arc
Gives a power source variable additional amperage during low voltage (short arc length) conditions while welding. Helps avoid “sticking” stick electrodes when a short arc length is used
Arc Control (Dig)
A group of thermal cutting processes that severs or removes metal by melting with the heat of an arc between an electrode and the work piece
Arc Cutting
A group of welding processes which produces coalescence of metals by heating them with an arc, with or without the application of pressure and with or without the use of filler metal.
Arc Welding
Automatically enhances Stick welding, especially on pipe, by focusing the arc and preventing the electrode from going out
Arc-Drive
Allows a TIG (Tungsten Inert Gas) arc to crater-out, allowing time for the addition of filler, without the loss of shielding gas. Eliminates the need for a remote control at arc end
Auto-Crater
The control of a process with equipment that requires little or no observation of the welding and no manual adjustment of the equipment controls
Automatic
A material (base metal, weld metal, or granular material) placed at the root of a weld joint for the purpose of supporting molten weld metal
Backing
A welding aid used to prevent melting through of a joint when performing a complete-joint penetration groove weld
Backing Bar
A shielding gas used on the underside of a weld bead to protect it from atmospheric contamination
Backing Gas
A weld bead applied to the root of a single groove joint to assure complete root penetration
Backing Weld
A joint between two members lying in the same plane
Butt Joint
A weld where two pieces of metal are to be joined are in the same plane
Butt Weld
Welding machine with limited maximum short circuit current. They have a negative volt-amp curve and are often referred to as “droopers.”
Constant Current (CC) Welding Machine
Welding machine that maintains a relatively stable, consistent voltage regardless of the amperage output. It results in a relatively flat volt-amp curve
Constant Voltage (CV), Constant Potential (CP) Welding Machine
Feeder operates from 24 or 115 VAC supplied by the welding power source
Constant-Speed Wire Feeder
The amount of electricity flowing past a point in a conductor every second
Current
The physical destruction of the completed weld in order to evaluate its
characteristics
Destructive testing
Current that flows in one direction and does not reverse its direction of flow
Direct Current (DC)
The direction of current flow through a welding circuit when the electrode lead is connected to the negative terminal and the work lead is connected to the positive terminal of a DC welding machine. Also called direct current, straight polarity (DCSP).
Direct Current Electrode Negative (DCEN)
The direction of current flow through a welding circuit when the electrode lead is connected to a positive terminal and the work lead is connected to a negative terminal to a DC welding machine. Also called direct current, reverse polarity (DCRP)
Direct Current Electrode Positive (DCEP)
The number of minutes out of a 10-minute time period an arc welding machine can be operated at maximum rated output
Duty Cycle
A type of welding that uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point
Electric Arc Welding
An arc welding process, which combines features of gas and shielded welding with those of electro-slag welding
Electro-Gas Welding
A welding process that is used for welding heavy structure components
Electro-Slag Welding
The process of joining two pieces of metal together that are perpendicular or at
an angle
Fillet welding
Automated electronically controlled welding system for simple, straight or circular welds
Fixed Automation
Automated, robotically controlled welding system for complex shapes and applications where welding paths require torch-angle manipulation
Flexible Automation
An arc welding process that produces coalescence of metals by means of tubular electrode. Shielding gas may or may not be used
Flux-Cored Arc Welding (FCAW)
A solid-state welding process, which produces coalescence of material by the heat obtained from a mechanically induced rotating motion between tightly butted surfaces. The work parts are held together under pressure
Friction Stir Welding
A solid welding process which produces coalescence of material by the heat obtained from a mechanically induced sliding motion between rubbing surfaces. The work parts are held together under pressure
Friction Welding
A process that uses gases and oxygen to weld and cut metals, respectively
Gas Cutting
An arc welding process where the arc is between a continuous filler metal electrode and the weld pool. Shielding from an externally supplied gas source is required
Gas Metal Arc Welding (GMAW)
An arc welding process where the arc is between a tungsten electrode (non-consumable) and the weld pool. The process is used with an externally supplied shielding gas
Gas Tungsten Arc Welding (GTAW)
Welding with the heat from an oxy-fuel flame, with or without the addition of filler metal or pressure
Gas Welding
Named for “globs” of weld metal transferring across the arc in a gravity feed. Droplets across the arc are usually larger than the electrode diameter. It does not produce a very smooth weld bead appearance, and some spatter can occur. Usually limited to the flat and horizontal welding positions, and not used on thin metals
Globular Transfer
A safety connection from a welding machine frame to the earth
Ground Connection
A unit of frequency that measures cycles per second
Hertz
Covers the entire frequency spectrum above 50,000 Hz. Used in TIG welding for arc ignition and stabilization
High Frequency
Used on some stick (SMAW) machines to make it easier to start difficult-to-start electrodes. Used for arc starting only
Hot Start
A combination of laser and arc welding which produces deep penetration welds with good tolerance to poor joint fit-up
Hybrid laser-arc welding
Power source that increases the frequency of the incoming primary power, thus providing for a smaller size machine and improved electrical characteristics for welding, such as faster response time and more control for pulse welding
Inverter
The total volts times amps divided by 1,000, demanded by a welding power source from the primary power furnished by the utility company
KVA (Kilovolt-amperes)
A measure of power, calculated as volts times amps divided by 1,000
KW (Kilowatts)
A joint between two overlapping members in parallel planes
Lap Joint
A process that severs material with the heat from a concentrated coherent beam impinging upon the work-piece
Laser Beam Cutting
A process that fuses material with the heat from a concentrated coherent beam impinging upon the members to be joined
Laser Beam Welding
A technology that is used for industrial manufacturing applications and uses a laser to cut materials
Laser Cutting
A welding process that offers low heat input and minimum distortion of welded plates and stiffeners
Laser Welding
This feature allows TIG arc starting without high frequency. Starts the arc at any amperage without contaminating the weld with tungsten
Lift-Arc
A device that provides a concentrated coherent light beam
Light Amplification by Stimulated Emission of Radiation (Laser)
A subtype of GMAW that uses an inert gas or gas mixture for shielding. Typically used on aluminum and other non-ferrous metals
MIG Welding
A gas that has been heated to at least partially ionized condition, enabling it to conduct an electric current
Plasma
An arc welding process that uses a constricted arc between a non-consumable electrode and the weld pool (transferred arc) or between the electrode and the constricting nozzle (non-transferred arc). Shielding is obtained from the ionized gas issuing from the torch
Plasma Arc Welding (PAW)
An arc cutting process using a constricted arc to remove the molten metal with a high-velocity jet of ionized gas from the constricting orifice
Plasma-Arc Cutting (PAC)
How well an electrical machine uses the incoming electrical power
Power Efficiency
Normally used on single-phase, constant current power sources to reduce the amount of primary amperage while welding
Power Factor Correction
The input line voltage and amperage available to the welding machine from the shop’s main power line, single-phase or three-phase AC power expressed in watts or kilowatts (KW)
Power Factor Correction Primary Power
A modified spray transfer process that produces no spatter, because the wire does not touch the weld puddle
Pulsed MIG (MIG-P)
A modified TIG process appropriate for welding thinner materials
Pulsed TIG (TIG-P)
For this variation of spray transfer, the welding machine “pulses” the output between high peak currents and low background currents. The weld pool gets to cool slightly during the background cycle, allowing for welding in all positions on either thin or thick metals
Pulsed-Spray Transfer
Sequencing and controlling the amount of current, the frequency and the duration of the welding arc
Pulsing
A process in which two pieces of metal are joined by passing current between electrodes positioned on opposite sides of the pieces to be welded. There is no arc with this process
Resistance Spot Welding (RSW)
Welding a lengthwise seam in sheet metal either by abutting or overlapping joints
Seam Welding
Welding where the equipment controls only the electrode wire feeding. The welding gun movement is controlled by hand
Semiautomatic Welding
Protective gas used to prevent atmospheric contamination of the weld pool. It is obtained from the electrode outer coating, often called flux. Filler metal is
primarily obtained from the electrode core
Shielding Gas
Named for welding wire touching the base metal many times per second, can be used in all welding positions and on all thicknesses of metal. Some spatter is produced
Short Circuit Transfer
Metal particles blown away from the welding arc. These particles do not become part of the completed weld
Spatter
Also known as “connecting”, joining materials by welding at a number of separate points, usually made on materials having some type of overlapping joint design
Spot Welding
Named for a “spray” of tiny molten droplets across the arc, usually smaller than the wire diameter. Uses relatively high voltage and amperage values, and the arc is “on” at all times after the arc is established. Very little if any spatter is produced. Usually used on thicker metals in the flat or horizontal welding positions
Spray Transfer
An arc welding process that melts and joins metals by heating them with an arc, between a covered metal electrode and the work
Stick Welding (SMAW or Shielded Metal Arc)
A process by which metals are joined by an arc or arcs between a bare metal electrode or electrodes and the work. Shielding is supplied by a granular, fusible material usually brought to the work from a flux hopper
Submerged Arc Welding (SAW)
A weld made to hold the parts of a weldment in proper alignment until the final welds are made
Tack welds
The maximum stress a material subjected to a stretching load can withstand without tearing
Tensile Strength
The degree to which a material conducts heat
Thermal Conductivity
A group of processes in which finely divided metallic or non-metallic
materials are deposited in a molten or semimolten condition to form a coating
Thermal Spraying
Stresses in metal resulting from non-uniform temperature distributions
Thermal Stresses
A fusion process, the required heat being evolved from a mixture of powdered aluminum and iron oxide
Thermite Welding
Also called gas tungsten arc welding (GTAW), this welding process joins metals by heating them with a tungsten electrode, which does not become part of the completed weld. Filler metal is sometimes used and argon inert gas or inert gas mixtures are used for shielding
TIG Welding
A device used in the TIG (GTAW) process to control the position of the electrode, to transfer current to the arc, and to direct the flow of the shielding gas
Torch
A low-voltage, low-amperage arc starting procedure for TIG (GTAW). The tungsten is touched to the workpiece; when the tungsten is lifted from the workpiece, an arc is established
Touch Start
Rare metallic element with extremely high melting point (3410° Celsius). Used in manufacturing TIG electrodes
Tungsten
The pressure or force that pushes the electrons through a conductor, causing current (amperage) to flow. Sometimes termed electromotive force (EMF), or difference in potential
Voltage
Feeder operates from arc voltage generated by welding power source
Voltage-Sensing Wire Feeder
Graph that shows the output characteristics (voltage and amperage capabilities) of a welding power source
Volt-Amp Curve
A tool for cutting a wide variety of materials using a very high-pressure jet of water, or a mixture of water and an abrasive substance
Water jet cutter
A discontinuity or discontinuities which, by nature or accumulated effect (for example, total crack length), render a part or product unable to meet the minimum applicable acceptance standards or specifications, designating rejectability
Weld Defect
The electrode and base metal that was melted while welding was taking place. This forms the welding bead
Weld Metal
Method by which metal is transferred from the wire to the molten puddle
Weld Transfer
The order in which weld beads are deposited in a weldment
Welding Sequence
A unit formed by welding together an assembly of pieces
Weldment
The speed and amount of filler metal fed into a weld, expressed in in/min or mm/s
Wire Feed Speed
A means to fasten the work lead (work cable) to the work (metal to be welded on)
Workpiece Connection
The conductor cable or electrical conductor between the arc welding machine and the work
Workpiece Lead
Substance with a low pH (<7) capable of burning or corroding by chemical action
Acid
Material consisting of two or more metals or a metal and a nonmetal
Alloy
(American Society of Mechanical Engineers) promotes the art, science and practice of multidisciplinary engineering around the globe
ASME
design code that governs vessels with pressures higher than 15 psi
ASME Code Section VIII
steel with 18% chromium and 8% nickel that is resistant to both rusting and corrosion
Austenitic (Stainless) Steels
plate for covering or closing the end of a pipe to gain a complete shutoff piping
Blind
Physical connection of two objects by a copper wire to prevent fire hazard loss
Bonding
Family of alloys of copper (60%-90%) and zinc (remaining portion)
Brass
Materials with hardness but little tensile strength, which break without significant deformation
Brittle
type of piping connection in which the parts to be joined are beveled and welded together
Butt-welded piping
constitutes most piping in process units because it is economical and has a wide temperature range. Mad from low carbon steel.
Carbon steel piping
a hard, relatively brittle alloy with a higher proportion of carbon than steel has, cast in a mold and used for conveying nonflammable fluids
Cast iron pipe
In a galvanic cell, the location of the positive pole to allow the circuit to be completed. In cathodic protection, this is the protected metal
Cathode
Technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell
Cathodic protection
substance with a high pH (>7) capable of burning or corroding by chemical action
Caustic
type of steel that has a certain quantity of chromium, which withstands corrosion very well
Chromium Steels
A measure of a materials change in length or volume with temperature
Coefficient of expansion
family of alloys that contains copper and zinc
Copper Alloys
electrochemical reaction between metal surfaces and fluids that results in the gradual wearing and tearing of metal
Corrosion
70% copper, 30% nickel
Cupronickel
the maximum pressure that the system can be exposed to and sets the system relief valve at the same pressure
Design pressure
two-valve system with vent to atmosphere to stop flow
Double block and bleed
Materials that can be easily molded or shaped without breaking or losing toughness (ex: copper, iron, or gold)
Ductile
a measure of a material’s ability to undergo permanent deformation before breaking (ex: stretching metal to a wire)
Ductility
inspection method to identify cracks or imperfections, which show up as a bright red line
Dye penetrant testing
short for the Latin phrase “exempli gratia” which means “for example”
e.g.
pipe fitting that looks like an “L” or partial “C” and used to route piping around bends
Elbow
Loss of ductility of a material, making it brittle
Embrittlement
A national pipe thread taper (NPT) subset, receives another tapered threaded connection
Female pipe thread
a permanent open spacer installed between two flanges connected to a thick plate of metal that can be rotated to stop piping flow
Figure eight (spectacle) blind a
specified using pounds rating - 150, 300, 600,900,1500 and 2500, which refers to the maximum allowable non-shock pressure (psig)
Fitting pressure ratings
disc, collar, or sing that attaches to pipe with the purpose of providing increased support for strength, blocking off a pipeline, or implementing he attachment of more items
Flange
pipe fitting used to mate against cast equipment using a gasket that covers the entire flange face
Flat face flange
A mechanical seal which fills the space between two “less than perfect” mating surfaces by filling irregularities, generally to prevent leakage from or into the joined objects, often made from rubber or plastic
Gasket
additional pressure in a system relative to atmospheric pressure. It is a convenient pressure measurement for most practical applications
Gauge pressure
procedure to connect an object to the earth using a copper wire and connected to a grounding rod or grounding device
Grounding
type of piping to keep the conveyed fluid hot in which the fluid is conveyed through the outer pipe and heating medium is conveyed through the inner pipe
Gutted piping
inspection method that uses tapping to determine metal thickness by sound and feel
Hammer testing
measure of how resistant a material is to permanent deformation. Test readings indicate strength and ductility
Hardness
A group of corrosion-resistant nickel alloys, characterized by high resistance to hydrochloric, sulfuric, phosphoric, acetic, and formic acids, to media containing ions of chlorine and fluorine, and to many organic media
Hastaloy
type of alloy steel that has larger quantities of secondary metals (10% or more) to produce a steel that is satisfactory for most services
High alloy steels
inside diameter
I.D.
type of piping to keep the conveyed fluid hot in which the fluid is conveyed through the inner pipe and a heating medium is conveyed through the jacket (the outer pipe)
Jacketed piping
an alloy with a relatively small amount of the secondary material (ex: carbon-,moly-, and chrome alloys)
Low alloy
type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel through the inclusion of small quantities of secondary metals (less than 10%)
Low alloy steels
relatively inexpensive material that is low in carbon, sulfur, and phosphorous and used for most plant applications
Low Carbon Steel
inspection method used to detect surface or near surface flaws by dusting iron powder over an induced magnetic field, and defects become outlined by the iron powder
Magnetic particle inspection
A National pipe thread taper subset, is inserted into a receiving tapered threaded connection
Male pipe thread
the opening to vessel, used as an access point for inspection or performing maintenance
Manway
A group of nickel alloys, primarily composed of nickel (up to 67%) and copper, with small amounts of iron, manganese, carbon, and silicon. Stronger than pure nickel and resistant to corrosion by many agents, including rapidly flowing seawater.
Monel
group of alloys that contains large amounts of nickel and is used around chemical plant where stainless steel is unsatisfactory
Nickel Alloys
means “in name only”
Nominal
North American set of standard sizes for pipes used for high or low pressures and temperatures.
Nominal Pipe Size (NPS)
metal that contains little or no iron (e.g., nickel alloys, copper alloys).
Nonferrous Alloys
A stub-pipe that is shop-welded to a vessel to facilitate welding a connecting pipe in the field.
Nozzle
outside diameter
O.D.
a physical object that has a self-reinforced end intended to be welded onto a hole in the wall of a pipe or a piping component. The other end is to be connected to another pipe or piping component
Olet
Device used for measuring flow rate, for reducing pressure
or for restricting flow (in the latter two cases it is often called a restriction plate)
Orifice Plate
Interaction between oxygen molecules and other substances (e.g., metal). With iron, this process causes rust
Oxidation
Thick piece of metal inserted between flanges to stop piping flow
Paddle blind
the area of the outside of the pipe, expressed in square feet per foot
of pipe.
Pipe external surface area
A joint or connector, as an elbow, union, or tee, used to connect two or more pipes in a pipe system
Pipe fitting
A bracket, clamp, clip, or loop used to suspend or support pipes by transferring the load of the pipe and conveyed material to a supporting structure
Pipe hanger
a fitting, consisting of a short piece of pipe of small diameter, usually provided with a male pipe thread at each end, for connecting two other fittings.
Pipe nipple
the approximate diameter of a pipe, specified using nominal size.
Pipe size
Prefabricated components of a piping system, including the pipes, flanges and fittings, fabricated before they are delivered to the construction area. Prefabrication allows more rapid field pipe assembly
Pipe spool
the thickness of the pipe wall, measured in inches, or similar unit, generally specified by pipe schedule
Pipe wall thickness
weight of water that could fit inside one foot of pipe, expressed in pounds per foot (or similar unit)
Pipe water weight
weight of pipe in pounds per foot (or similar unit)
Pipe Weight
system of pipes used to convey all kinds of fluid materials (liquids and gases).
Piping
A pictorial representation of a piping system in three dimensions. Drawing is not to Scale, does not show size of piping or components
Piping isometric drawing (iso)
A two-dimensional drawing of a three-dimensional object, using two or more additional drawings to show additional views of the object. Drawing is to scale, including representation of piping and components
Piping orthometric drawing (ortho)
inspection method used to find defects in plates and welds and determine pipe and tube wall thickness
Radiographic (x-ray) testing
pipe fitting used to join pipe to other flanged equipment, pipe, etc. and has a gasket that fits inside the bolted area
Raised face flange
pipe fitting used to join pipe to other flanged equipment, pipe, etc. that uses a metal ring as a gasket
Ring joint flange
Highly active metals used to prevent a less active material surface from corroding, created from a metal alloy with a more negative electrochemical potential than the other metal it will be used to protect (e.g., zinc, magnesium, or aluminum alloys)
Sacrificial anode
The exterior wall of a vessel
Shell
type of piping connection in which a pipe is inserted into a larger fitting
before being welded with a fillet weld
Socket-welded piping
a branch connection fitting, which utilizes the basic weldolet design configuration with a socket weld outlet
Sockolet
Storage vessel used for high-pressure fluids or compressed gases with a very strong structure and no weak points. Shaped like a large ball
Spherical tank
Storage vessel shaped like an ellipsoid, commonly seen in water towers
Spheroidal tank
Standard (pipe schedule)
STD
a measure of the maximum load that a material can take before it permanently deforms or breaks
Strength
mechanical-chemical type of deterioration
Stress-corrosion cracking
pipe fitting that looks like the letter “T”, used to make branch connections
Tee
the pressure to which pipelines, boilers, vessels, etc. are tested for strength and leaks before being placed into service
Test Pressure
a branch connection fitting, which utilizes the basic weldolet design configuration with a threaded outlet
Threadolet
ability of a material to absorb energy and permanently deform without breaking
Toughness
type of piping that keeps conveyed fluid hot by wrapping copper tubing around process pipe and covering with heat transfer cement or insulation and passing low-pressure steam or hot oil through the tubing
Traced Piping
A caliper equipped with an adjustable or removable leg to permit use of the caliper in narrow or confined spaces
Transfer caliper
inspection method used to measure metal thickness through a drilled hole
Trepanning
an opening that allows air, gas, or liquid to pass out of or into a confined space
Vent
sketches that include information necessary for selection, use, and need for periodic inspection of materials used to make vessels
Vessel design sheets
most common form of inspection, performed visually
Visual inspection
ability to be welded. Many metals and thermoplastics can be welded, but some are easier to weld than others
Weldability
an economical butt-weld branch connection, used when the branch is much smaller than the main pipe
Weldolet
Extra strong (pipe schedule)
XS
Double extra-strong (pipe schedule)
XXS
A treatment for the removal of rust and mill scale from steel by immersing it in an acid solution containing an inhibitor. Pickling should be followed by thorough washing and drying before painting.
Acid pickling
A process of atomizing paint by forcing it through an opening at high pressure. This effect is often aided by flashing (vaporization) of the solvents, especially if the paint has been previously heated
Airless spraying
(1) Having properties of an alkali. (2) Having a pH greater than 7
Alkaline
A coating consisting of a mixture of metallic aluminum pigment in powder or
paste form dispersed in a suitable vehicle
Aluminum paint
A film on a metal surface resulting from an electrolytic treatment at the anode
Anodic coating
A coating, composed wholly or partially of an anodic metal (in sufficient quantity to set off electrochemical reaction), which is electrically positive to the substrate to which it is applied
Anodic metallic coating
Forming a conversion coating on a metal surface by anodic oxidation; most frequently applied to aluminum
Anodizing
A coating used for preventing the corrosion of metals which has been specially formulated to prevent the rusting of iron and steel
Anticorrosion paint or composition
The nonvolatile portion of the liquid vehicle of a coating
Binder
Asphalt or tar compound used to provide a protective finish
Bituminous coating
Cleaning and roughening of a surface (particularly steel) by the use of a metallic or nonmetallic abrasive that is propelled against a surface by compressed air, centrifugal force, or water
Blast-cleaning
The formation of swellings on the surface of an unbroken paint film by moisture, gases or the development of corrosion products between the metal and the paint film
Blistering
Whitening and loss of gloss of a usually organic coating caused by moisture
Blushing
Application of a coating by means of a brush
Brushing
Paint supplied in dry powder form, based essentially on Portland cement, to which pigments are sometimes added for decorative purposes. This dry, powdered paint is mixed with water immediately before use
Cement paint
A coating developed on a metal surface by a high-temperature diffusion process (as carburization, calorizing, or chromizing)
Cementation coating
A protective or decorative coating that is produced deliberately on a metal surface by reaction of the surface with a chosen chemical environment
Chemical conversion coating
A coating in which the binder or vehicle is a combination of coal tar and epoxy resin
Coal-tar epoxy coating
A coating in which the binder or vehicle is a combination of coal tar with a polyurethane resin
Coal-tar urethane coating
A number of coats separately applied in a predetermined order at suitable intervals to allow for drying or curing
Coating system
A liquid, liquefiable, or mastic composition that has been converted to a solid protective, decorative, or functional adherent film after application in a thin layer. A coating is an electrical insulating covering applied to a metal surface as passive protection against external corrosion
Coating
Two or more paints or varnishes that can be mixed without producing any undesirable effects such as precipitation, coagulation, or gelling are said to be compatible. Different coats of paint that can be associated in a painting system or other coating systems without producing undesirable effects are also compatible
Compatible
A coating consisting of a compound of the surface metal, produced by chemical or electrochemical treatments of the metal
Conversion coating
The separation of metallic material from an attacking medium by paint or coating
Corrosion protection
The temperature at which moisture will condense
Dew point
DFT measurement instruments consist of magnetic gauges that measure the
thickness of a dry film of a nonmagnetic coating applied to a magnetic substrate
DFT measurement
A chromate conversion coating produced on magnesium alloys in a boiling solution of sodium dichromate
Dichromate treatment
The application of metallic coating, the chemical composition of which was modified by diffusing this at the melting temperature into the substrate
Diffusion coating
The time required for an applied film of coating to reach the desired stage of cure, hardness, or nontackiness
Drying time
Severe loss of ductility of a metal (or alloy)
Embrittlement
A substance composed of a specially processed coal-tar pitch or bitumen, combined with an inert mineral filler
Enamel
Destruction of metals by the abrasive action of moving fluids accelerated by the presence of solid particles in suspension
Erosion
Test the adhesion of the coatings after application
Field adhesion testing
The final coat in a painting system
Finish coat (topcoat)
The impingement of an intensely hot flame to the surface of structural steel, resulting in the removal of mill scale and the dehydration of any remaining rust, leaving the surface in a condition suitable for wire brushing, followed by the immediate application of paint
Flame cleaning
Thermal spraying in which coating material is fed into an oxyfuel gas flame, where it is melted
Flame spraying
Material used during welding, brazing, or braze welding to clean the surfaces of joints, prevent atmospheric oxidation, and to reduce impurities
Flux
The application of a coating of zinc to steel by a variety of methods
Galvanizing
To produce a zinc-iron alloy coating on iron or steel by keeping the coating molten after hot-dip galvanizing until the zinc alloys completely with the base metal
Galvanneal
A discontinuity in a coating (such as porosity, cracks, etc.) that allows areas of base metal to be exposed to any corrosive environment that contacts the coated surface
Holiday
The paint intended to be used between the primer and topcoat in a paint system
Intermediate coat (undercoat)
Leakage resistance of pipe or resistance of pipe radially to remote earth
Leakage or coating resistance
Includes hand cleaning and power tool cleaning
Manual cleaning
Application of a spray coat of metal (usually zinc or aluminum) onto a prepared surface
Metal spraying
One or more layer of metal on a steel base (base material)
Metallic coating
The term used for the surface oxides produced during hot rolling of steel. It breaks and flakes when the steel is flexed and paint applied over it may fail prematurely
Mill scale
Being or composed of hydrocarbons or their derivatives, or matter of plant or animal origin
Organic
Any pigmented liquid, liquifiable, or mastic composition designed for application to a substrate in a thin layer that is converted to an opaque solid film after application. Used for protection, decoration, or identification, or to serve some other function
Paint
A coating (usually green) that forms on the surface of metals, such as copper and copper alloys, exposed to the atmosphere
Patina
Forming an adherent phosphate coating on a metal by immersion in a suitable aqueous phosphate solution
Phosphating
A form of chemical and electrolytic removal or loosening of mill scale and corrosion products from the surface of a metal in a chemical solution (usually acidic). Electrolytic pickling can be anodic or cathodic, depending on the polarization of metal in the solution
Pickle / pickling
A solution, usually acid, used to remove mill scale or other corrosion products from a metal
Pickle
Deposition on critical areas of metal coatings resistant to wear and abrasion, by means of a high-velocity, high-temperature ionized inert gas jet
Plasma plating
A thermal spraying process in which the coating material is melted with heat from a plasma torch that generates a nontransferred arc: i.e., molten coating material is propelled against the base metal by hot, ionized gas issuing from the torch
Plasma spraying
Usually refers to the chemical treatment of unpainted metal surface before painting
Pretreatment
The first complete coat of paint of a painting system applied to a surface
Primer
The rapid cooling of metals (often steel) from a suitable elevated temperature. This generally is accomplished by immersion in water, oil, polymer solution, or salt, although forced air is sometimes used
Quenching
The component of either a liquid or solid solution that is present to a greater or major extent; the component that dissolves the solute
Solvent
A method of application in which the coating material is broken up into fine mist that is directed onto the surface to be coated
Spraying
Any method of treating a surface to get it ready for painting
Surface preparation
A primer containing solvent and whose base consists of resins and synthetic
plasticizers
Synthetic primer
A group of coating or welding processes in which finely divided metallic or nonmetallic materials are deposited in a molten or semimolten condition to form a coating. The coating material may be in the form of powder, ceramic rod, wire, or molten materials
Thermal spraying
An intermediate coat used to bond different types of paint coats; used to improve the adhesion of succeeding coatings
Tie coat
The process of coating metal with a very thin layer of molten solder or brazing filler metal
Tinning
Blast-cleaning of metal using high-velocity water with or without the addition of an abrasivebushing
an adapter threaded to permit joining of pipes with different diameters
Water-blasting
