Energy Plant Piping and Valves

Flashcards covering introductory plant valves, piping materials, connection methods, expansion devices, drainage systems, steam traps, and insulation.

Fluid Friction Loss

The loss of pressure or 'head' that occurs in a pipe due to the effect of the fluid's viscosity near the internal pipe surface.

Pressure Drop

The reduction in fluid pressure that occurs when fluid passes through a restriction or constriction within a valve or fitting.

Valve Trim

The internal components of a valve, which typically include the disc, seat, stem, guide bushings, and packing.

Valve Bonnet

The removable upper housing of a valve body that provides access to the internal trim, attached via welded, bolted, or threaded connections.

Gate Valve

A bi-directional valve designed for isolation and on/off service that offers minimal pressure drop across the fully opened flow path.

Wire Drawing

The erosion of a valve's disc and seat caused by velocity effects when using a gate valve for throttling service, preventing complete shutoff when closed.

Rising Stem Gate Valve

A gate valve design where the stem is attached to the disc and moves vertically when operated, providing visual indication of valve position.

Non-Rising Stem Gate Valve

A gate valve design where the stem rotates internally without moving axially, making it ideal for locations with restricted headroom.

Globe Valve

A valve that changes fluid flow direction twice across a disc and seat parallel to the flow path, designed for throttling service but causing the largest pressure drop among common valves.

Z-Body Globe Valve

The most common globe valve construction style used for standard throttling applications.

Y-Body Globe Valve

A globe valve design with the seat and stem positioned at a 45^\bar{\text{o}} angle to reduce fluid friction loss, suitable for high-pressure and severe service.

Angle Globe Valve

A single-ported globe valve featuring a single 90^\bar{\text{o}} turn, functioning as both a valve and an elbow for moderate operating conditions.

Needle Valve

A flow control valve featuring a sharp, pointed disc and fine stem threads used for precise flow metering applications like continuous blowdown or chemical injection.

Continuous Blowdown (CBD)

The continuous removal of dissolved solids from boiler water to control conductivity.

Butterfly Valve

A lightweight, low-torque final control element with a circular disc that rotates 90^\bar{\text{o}} to control flow, offering negligible pressure drop and self-cleaning operation.

Electrically Driven Worm & Gear Actuator

A motorized valve operating mechanism utilizing spur gears, a worm gear drive, torque switches, and limit switches to provide remote operation, visible position indication, and controlled operating speed.

Wafer Butterfly Valve

A butterfly valve body style clamped directly between two pipe flanges using long studs that pass around the outer edge of the valve.

Lug Butterfly Valve

A butterfly valve body design featuring threaded bolt holes (lugs) around its perimeter, allowing pipe flanges from either side to bolt directly to it.

Ball Valve

A quarter-turn valve containing a spherical plug with a port through its center, providing tight shutoff without requiring internal lubrication.

Plug Valve

A quick-opening quarter-turn valve consisting of a tapered vertical cylinder or plug fitted into the valve body housing.

Check Valve

A valve that automatically permits fluid flow in one direction only while preventing reverse backflow.

Non-Return Steam Stop Valve (NRV)

A specialized boiler valve that acts as both an isolation stop valve and a check valve, preventing steam backflow into an offline or damaged boiler connected to a common header.

Pressure Reducing Valve (PRV)

An automatic regulating valve designed to reduce higher upstream fluid pressure to a constant lower downstream pressure.

Internal Diaphragm PRV

A pressure reducing valve where downstream pressure acts under an integral internal diaphragm opposed by an adjustable control spring.

External Diaphragm PRV

A pressure reducing valve where the sensing diaphragm is isolated from the main body fluid temperature by an external sensing line or condensate leg.

Power Piping (ASME B31.1)

Piping systems installed in electric power generating stations, industrial and institutional plants, geothermal utility plants, and central heating/cooling systems.

Process Piping (ASME B31.3)

Piping systems installed in petroleum refineries, chemical, pharmaceutical, textile, paper, semiconductor, and cryogenic processing plants.

Cast Iron Pipe

A brittle pipe material with high resistance to corrosion and abrasion, restricted to low-pressure and low-temperature applications up to 232^\bar{\text{o}}\text{C}.

Malleable and Ductile Iron

Durable cast iron variants featuring high mechanical strength and corrosion resistance, commonly used for screwed pipe fittings and potable water service.

Nominal Pipe Size (NPS)

The standard North American sizing system for pipe, where sizes up to $12\text{ in}$ represent nominal inside diameter and sizes above $12\text{ in}$ equal actual outside diameter.

Threaded Pipe Fittings

Commercial pipe joinery components (such as couplings, tees, elbows, nipples, and unions) used for joining pipe runs generally under $2\text{ in}$ ($50\text{ mm}$) in diameter.

Pipe Dope

A liquid thread joint compound applied to male pipe threads to lubricate assembly and seal small imperfections against leakage.

Bushing

A threaded fitting with male threads on the outside and smaller female threads on the inside used to join two pipes of different sizes.

Union

A three-piece screwed pipe fitting that enables disassembly of a pipe line without cutting pipe or unthreading adjacent connections.

Swage

A male-ended pipe reducer commonly used in process industries to connect pipe fittings to threaded connections.

Flange Types

Standard pipe collar attachment designs including screwed flanges, loose lap-joint (Van Stone) flanges, welded slip-on flanges, and butt-welded weld-neck flanges.

Van Stone Flange

A loose lapped flange that slides over a pipe stub end, providing easy bolt alignment and reduced material cost in alloy piping systems.

Full Face Gasket

A gasket covering the entire flange face, complete with punched holes to accommodate the flange studs, used primarily in low-pressure service.

Flat Ring Gasket

A gasket designed to fit entirely within the circle of flange studs, covering only the raised contact face of the flange.

Ring Joint Gasket (RTJ)

A metallic ring gasket (oval or octagonal) designed to fit into a matching groove machined into high-pressure flange faces.

Gasket Identification Marking

Standardized stamp markings on a gasket specifying manufacturer name, nominal pipe size, pressure rating, winding metal, filler material, and applicable ASME specification.

Flange Identification Marking

Standardized rim stampings on a pipe flange indicating logo, nominal pipe size, face type, pressure rating, material grade, and heat number.

Expansion Bend Types

Fabricated piping configurations—including L-bends, Z-bends, U-bends, symmetric loops, and guided loops—designed to absorb thermal expansion stresses without mechanical joints.

Slip Expansion Joint

A telescoping piping joint consisting of a inner slip pipe sliding within an outer sleeve sealed with packed glands or O-rings.

Corrugated Expansion Joint

A flexible, bellows-type expansion joint suitable for lower pressure piping systems up to $2000\text{ kPa}$.

Variable Spring Hanger

A pipe support incorporating a helical spring to handle piping subject to thermal expansion and load variations.

Constant Support Hanger

A pipe hanger utilizing a spring and cam/rocker assembly to supply constant supporting force across large vertical movements.

Pipe Anchor

A rigid support fixing a pipe solidly at a specific point, forcing thermal growth to move in designated directions away from the anchor.

Pipe Guide

A restraint framing a pipe to permit axial sliding while preventing movement in lateral or unwanted directions.

Pipe Shoe

A structural saddle attached beneath insulated or uninsulated pipe that elevates it to slide along supporting steel beam base plates.

Water Hammer

A destructive hydraulic shock caused by rapid stopping of liquid flow, collapsing steam voids, or high-velocity condensate slugs colliding with pipe fittings or closed valves.

Condensate Induced Water Hammer

Overpressurization and high-impact shock generated when steam pockets in a pipe condense rapidly, creating a vacuum void into which water surges and collides.

Steam Separator

An inline vessel that removes entrained moisture droplets from wet steam using internal baffle plates or cyclone centrifugal action.

Float and Thermostatic Trap (F&T)

A mechanical and thermostatic steam trap featuring a ball float for continuous condensate discharge and a thermostatic element for automatic air venting.

Inverted Bucket Steam Trap

A mechanical steam trap operating on the buoyancy of an submerged inverted bucket, discharging condensate intermittently when steam inside the bucket condenses.

Thermostatic Bellows Trap

A steam trap containing a liquid-filled flexible bellows element that expands to close the valve near steam temperature and contracts to discharge cooler condensate.

Bi-Metallic Steam Trap

A thermostatic trap that operates using a strip composed of two dissimilar metals bonded together, which flexes under temperature changes to control valve opening.

Impulse Steam Trap

A thermodynamic steam trap operating on pressure variations across a moving piston disc valve and control cylinder as flashing condensate passes through.

Thermodynamic Disc Trap

A compact steam trap utilizing dynamic enthalpy and pressure differences between steam and condensate acting on a simple flat floating disc.

Calcium Silicate Insulation

A rigid, non-combustible insulation material made of lime and silica, suitable for hot piping applications operating between 38^\bar{\text{o}}\text{C} and 650^\bar{\text{o}}\text{C}.

Glass Fibre Insulation

A non-combustible, sound-absorbing insulation material formed from processed glass fibers, rated for temperatures up to 454^\bar{\text{o}}\text{C}.

Mineral Fibre Insulation

A non-combustible insulation made from rock and slag fibers bonded with heat-resistant binder, rated for high-temperature service up to 1040^\bar{\text{o}}\text{C}.

Refractory Fibre Insulation

High-temperature ceramic and mineral fiber insulation containing alumina and silica, rated for extreme heat applications up to 1650^\bar{\text{o}}\text{C}.

Reflective Metal Insulation

Insulation constructed from highly polished stainless steel sheets with intermediate air gaps, used for extreme temperature service above 1040^\bar{\text{o}}\text{C}.