Valve & Control Valve Masterclass: Design Selection & Sizing

Identify valve parts—body, bonnet, stem, actuator, packing, seat, disc—and describe four basic flow control elements used in valve design and stem leakage control.

Explore how a valve controls flow and pressure by stopping, starting, varying, and regulating within a system, while introducing designs and the basic parts: body, bonnet, trim, actuator, packing.

Evaluate the valve body, or shell, as the primary pressure boundary and framework that resists fluid pressure and connects inlet and outlet piping via bolted flanges.

Explains the valve bonnet as the cover and second pressure boundary, connected by bolted or welded joints, with designs ranging from simple covers to supporting internals such as stem.

Explore valve trim, including disc, seat, stem, and sleeve, and compare rotational and linear trim designs through a 3D animation showing how disc position to the seat controls flow.

Explore how the disc acts as a pressure boundary that permits or blocks flow. Understand seating surface quality, wear resistance via hard facing, and the role of seal rings.

Stem connects the actuator to the disc, positions it, and uses threaded or welded joints with a seal surface to prevent leakage; stems are rising or non rising.

Learn the basic principles and operation of valve actuators—manual handwheel, motor, solenoid, pneumatic, and hydraulic operators—driving the stem and disk assembly, with bonnet or yoke support, outside the pressure boundary.

Explore valve packing concepts, including how packing glands seal the bonnet using Teflon or BTF, and learn the critical balance between packing compression, leakage prevention, and stem movement.

Explore diverse valve types—globe, gate, ball, plug, butterfly, diaphragm, check, pinch, and safety valves—and four flow-control methods for throttling or stopping flow across applications.

Identify and describe valve types, their main applications and functions, to ensure correct design selection and safe operation across diverse environments, fluids, and flow conditions.

Explore gate valves, a linear motion valve used to start or stop flow, with a disc sealed 360 degrees when closed and minimal resistance when open, not suitable for throttling.

Watch a 2D dismantling of a gate valve, detailing steps from unscrewing the gland to removing the bonnet, including gland cover, backing, bonnet nuts, body, stem, wedge, and handwheel.

Learn to dismantle a rising stem gate valve in a 3d view, unscrewing the gland, bonnet nut, and handwheel, then removing the stem, wedge, gland, thrust collar, and bonnet.

Explore gate valve disk designs, including solid wedge, flexible wedge, split wedge, and parallel disk, with emphasis on replaceable seats, erosion resistance, and avoidance of binding from thermal transients.

Gate valves have rising stem and non rising stem designs. Non rising stems thread into gate and stay stationary as the handwheel turns; rising stems lift the gate when opened.

Explore gate valve seat design, including integral seats versus seat rings, with threaded, pressed, or welded installations, and note how hard facings and temperature demands drive material and replacement options.

Explore globe valves as linear motion valves used to start, stop, and regulate flow; learn about their perpendicular disc-seat action, throttling capability, and tradeoffs like head loss and noise.

Explore 3d dismantling of a globe valve, step by step removing gland knots, gland cover, packing, bonnet knots, body, disc, stem ring, handwheel, stem, gland, and finally the valve bonnet.

Learn how to dismantle a globe valve in 2d, following a step-by-step sequence: unscrew the gland, remove the bonnet, rotate the disk, slide the stem, and detach the bonnet.

Explore the Z-body globe valve, the simplest, most common water design, featuring a Z-shaped diaphragm that houses the seat and a bonnet-secured stem.

Reduce high pressure drop with Y-body globe valves, featuring a white body globe valve and a 45 degree seat and stem for a straighter flow and a pressure resistant envelope.

Explore globe valve angle design, featuring a right-angled body that enables a single 90-degree turn and downward, symmetric discharge, with three-dimensional animation showing its valve and piping elbow function.

Explore globe valves and their disk designs: bowl, composition, and plug disks. Identify how each design affects throttling, sealing, erosion resistance, and use in steam or hot water applications.

Globe valves use two disc-to-stem connections: T-slot and disc-nut construction. In the T-slot design, the disc slips over the stem; the other method screws the disc to the stem.

The globe valve seat design may be integral or screwed. Back seats seal between the stem and bonnet; the disc seats there when open to prevent pressure.

Globe and angle valves direct flow with pressure under the disc for low temperatures, protecting backing and reducing erosion; for high temperature steam, place pressure above the disc.

Ball valves are rotational motion valves that use a spherical ball to rotate and align a flow hole with the valve body to start or stop fluid flow.

Explore the internals of a flange and ball valve—the body, ball, seats, and spindle. Compare venturi, full port, and reduced port patterns and how a quarter-turn closes the flow.

Dismantle a 3d ball valve model by removing the handle, unscrewing the spindle nut, seal ring, and flange nuts, then slide out the ball and spindle to reveal valve body.

Demonstrates dismantling a ball valve with a 2d model by unscrewing the spindle nut, removing seal ring, detaching flanged ends, sliding out the ball, removing the spindle and valve body.

Ball valve actuators vary from quick acting 90-degree turn to planetary gear systems; the latter enables a small handwheel and reduced operating force for large valves.

Explore ball valves' advantages and disadvantages: low cost, low maintenance, compact design, no lubrication, tight sealing, and quick quarter-turn operation; note throttling limits and erosion from high-velocity flow.

Explore ball valves in reduced port and full port patterns, noting that the full port design uses a bore equal to the pipe's inside diameter.

Explore the exploded view of a ball valve to see metallic balls and elastomeric seeds, including plastics, with materials like Teflon PTF and nylon neoprene, noting elevated-temperature limits and compatibility.

Illustrates a ball valve in open position, with the hole aligned to inlet/outlet, and shows a stem that fits a rectangular end into a ball slot to rotate the ball.

Explore how ball valves open and close with 90-degree rotation, while some allow 360-degree rotation. Learn to read handle position and groove or marking flow paths, including multi-port valves.

Identify plug valves as rotational motion devices that stop or start fluid flow using a solid plug with a bored passage aligned to ports in the open position.

Explore the internal components of a plug valve, from the lubricant screw and gland to the plug and body, through a detailed 3d model.

Dismantle a 3D model of a typical plug valve by removing the handle, unscrewing the gland, and removing the packing, cover, and body, leaving the plug.

Dismantle a plug valve using a 2D A2D model by unscrewing gland, removing gland cover and packing, then removing cover nut, cover, stem plug assembly, and valve body.

Explore plug valves in lubricated and non-lubricated designs, and examine the variety of port openings and plug designs that influence performance.

Examine the plug valve cut section to understand plug shapes and port options. Identify rectangular, round, and diamond ports, and note full port, standard round port, and throttling venturi types.

Learn about multiport plug valves for transfer lines, including three-way and four-way configurations, port arrangements, and the limits of shut-off, guiding proper design choices.

Explore lubricated plug valve design, where lubricant sealed channels create a positive seal, hydraulic jacking eases turning, prevents solids lodging, and protects wear surfaces under high differential pressure.

Explore non-lubricated plug valve designs, including lift type and elastomer sleeve variants, with external lever or cam lifting, PTFE sleeves creating a durable, self-lubricating primary seal.

Explore plug valve internals, including single, screwed, and bolted glands, and learn how proper gland tightness seats the plug without causing metal-to-metal contact or unseating.

Explore diaphragm valves as linear motion devices that start, regulate, and stop flow, delivering leak-tight performance for low-pressure service with smooth passages and fluid isolation.

Disassemble a diaphragm valve 3D model by unscrewing the bonnet nut, removing the body, detaching the diaphragm from the stem, and removing the handwheel, compressor stem, lock pin, nut, and bonnet.

Dismantle a diaphragm valve using an A2D model. Unscrew bonnet nuts, remove the body, detach the diaphragm from the stem, and disassemble the compressor stem, handwheel, lock pin, and bonnet.

Explore two diaphragm valve types—wear type and straight through—and how the diaphragm seals the body. Open, throttled, and closed positions are shown; diaphragm valves suit corrosive fluids and slurries.

Diaphragm valves isolate the mechanism from the process and resist clogging, with diverse diaphragms; select by temperature, chemical exposure, and concentration, noting elastomer limits.

Explore diaphragm valve bonnet designs, including quick-opening bonnets with lever operators, interchangeable standard bonnets, and multiple actuators (chainwheel, extended stem, bevel gear, nomadic, hydraulic) for vacuum or sealed service.

Explore pinch valves, a simple externally operated design that isolates the fluid. They offer throttling from 10% to 95% and excel with slurries and solids, including corrosion-prone fluids.

Analyze pinch valve body design, featuring fabric-reinforced molded bodies, 250°F temperature rating, and size-dependent pressures, with exposed or metal-enclosed sleeves and hydraulic or pneumatic actuation to shut flow.

Operate a butterfly valve, a rotary motion valve that starts, stops, and throttles flow with a 90-degree disc rotation; the wafer design locks via a locating pin, lever, and spring.

Learn how to dismantle a butterfly valve with a 3d model, removing the handle pin, lever assembly, locating plate, oil seal, plug, stem, disc, and valve body.

Examine butterfly valve seat designs, including wafer valves, from elastomeric seats sealing against the inside diameter periphery. Learn how clamp ring solutions prevent o-ring extrusion and compare to metal seats.

Understand butterfly valve disk and stem assembly, where the disk is bored to fit and rotate with the stem, secured by bolts or pins, with stuffing box or o-ring seals.

Explore how needle valves enable fine flow control with a long tapered needle acting as the throttling disk. Review their basic components and how the stem and handle regulate flow.

Dismantle a 3d needle valve model by unscrewing the nut and gland, removing the handle, and rotating the stem and bonnet anti-clockwise. Then slide bonnet off to reveal the stem.

Apply needle valves to minimize fluctuations in pump discharge pressure within constant pressure pump governors, and use them in automatic combustion control systems for precise flow regulation.

Analyze bar stock body needle valves and globe types, featuring a ball swiveling stem for damage-free seating, and metering valves with a thin orifice for linear flow.

Explore needle valves and their stem packing, featuring two styles, no backing rings or backing cylinders, and replaceable seats for easy maintenance.

Understand how check valves prevent reverse flow in piping systems, opening with fluid pressure and closing by weight, back pressure, or spring, including swing, tilting, disc, piston, butterfly, and stop.

Explore swing check valves that allow full flow, automatically close to prevent backflow, and feature cap, disc, hinge, seat ring, and body in straight or y-pattern designs.

Dismantle a swing check valve with a 3D model, starting with unscrewing the nuts and removing the cup. Then extract the disc hinge pin, hinge disk assembly, and seat.

Explore a 2D dismantling of a swing check valve, removing nuts, cup, the disc hinge pin and assembly, the seat, and finally the valve body.

Discover tilting disc check valves, delivering low flow resistance with a straight-through design. See how airfoil disc floats with flow, seals before reverse flow, and fits horizontal or vertical installations.

Lift check valves provide reliable flow control in piping with globe valves, suited for horizontal or vertical lines with upward flow, including steam, air, gas, water, and vapor lines.

Dismantle a lift check valve using a 3d model, unscrewing the knots. Then remove the cup guide assembly, the disk, and the body with the seat ring.

Dismantle lift check valve with a 2D A2D model, unscrew cup nuts, remove cap guide assembly, slide and remove disk, expose valve body with seat ring.

Analyze a piston check valve’s dashpot cushion, its flow characteristics similar to a lift check valve, and its under-seat installation for angle valves in water, steam, and air systems.

Explore the butterfly check valve with a flexible sealing member, clamp plate, hinge clamp, and hinge post that allow unobstructed disc movement from open to closed, horizontally or vertically.

Explore stop check valves, a hybrid of lift check and globe valves, where a stem seals the seat and, when opened, acts as a lift check while limiting disc travel.

Explore how pressure relief valves protect pressurized systems during overpressure by opening at set pressure to provide rated capacity and closing when the system returns to safe level.

Explore the two categories of pressure relief devices—reclosing and non reclosing—and review pressure relief valves, safety valves, relief valves, safety relief valves, ruptured disk devices, and breaking pin devices.

Discover essential safety valve terminology, including opening pressure, set pressure, closing pressure, receding pressure, blow down, overpressure, and back pressure types.

Differentiate relief valves from safety valves by opening behavior: relief valves open gradually above set point; safety valves pop and reset below it, illustrating blowdown for incompressible versus compressible fluids.

Examine the safety valve’s rapid pop action, its internal components, and how the spring, blowdown rings, and nozzle control overpressure and blowdown for compressible fluids such as steam and air.

Identify the three safety valve pressures—set pressure, overpressure, and reset pressure—and explain how blowdown and lift determine maximum discharge for compressible and incompressible fluids.

Demonstrate dismantling a safety valve with a 3D model, removing the wire, cap, spring, bonnet, spindle, disk assembly, bellows, blow down rings, and locking pin.

This lecture demonstrates dismantling a 2D model of a safety valve, guiding step-by-step removal of seal wire, cap, spring, bonnet, spindle, blowdown rings, bellows, disc, nozzle, and valve body.

Relief valves gradually lift in proportion to the increase in pressure over the opening pressure to relieve overpressure, while safety valves snap open and stay open until reset pressure.

Observe a relief valve in a 2d cross-sectional view: the disk lifts above the set pressure to relieve excess pressure and spill excess capacity back to the oil reservoir.

Dismantle a relief valve in a 3D model by removing the seal wire, rotating the cap anticlockwise, and stepwise disassembly of the disk, stem, spring, and valve body.

Dismantle a relief valve using a 2d model by removing components in sequence: seal wire, cap, spring adjuster, steel wire, locking pin, inlet connection, disc, stem, spring, and valve body.

examine spring loaded pressure relief valves, detailing the disc, nozzle, and adjustable spring that set opening pressure, and how a huddling chamber boosts lift and controls blow down.

Explore advanced spring loaded valve design through a 3d animation, reinforcing design selection and sizing concepts.

Select materials of construction for process-fluid compatibility, strength for pressure and temperature, chemical resistance, guiding-surface bearing properties, precise seating finishes for tight shut-off, and account for thermal expansion.

Explore back pressure effects on pressure relief valves in open and closed systems, including superimposed back pressure and changing set pressure, and learn balanced bellows design to stabilize set pressure.

examine dynamic back pressure after valve opening, caused by downstream flow; it may affect lift and flow, not opening pressure. balanced designs when built-up pressure exceeds 10% of cold differential.

Design pressure relief valves for tight shut off with precise port alignment and optically flat seating to prevent seat leakage and premature opening, and operate below 90% of set pressure.

Learn to test safety relief valves with nitrogen or air on the SVM 2200 bench, set pressure, adjust spring load, and perform a C6 leak test with a bubble counter.

Steam traps discharge condensate without letting live steam escape, protecting efficiency and preventing water hammer. Four common types—float, thermostatic, thermodynamic, inverted bucket—operate via density, temperature, and kinetic energy.

Explore how a float steam trap, a density-operated, flow-type trap, uses a condensate level and a rising float to open a discharge valve and steadily discharge condensate.

The lecture explains thermostatic steam traps with a bellows fluid that expands and contracts to open or close the discharge valve as condensate and steam interact.

Describe how thermodynamic steam traps operate as kinetic energy operated traps that distinguish steam from condensate by velocity and flash steam, cycling the disc between seat and discharge.

Discover the inverted bucket steam trap, a density-operated, two-part mechanism using a bucket and a lever to intermittently open a discharge valve for condensate while venting air to prevent binding.

Master valve and control valve design selection and sizing. Ensure you complete the current section before proceeding to the next.

Explore how strainers protect equipment and pumps from dirt and debris during startup, with an overview of common strainer types and preview of detailed examinations in upcoming videos.

A WAI strainer upstream of traps, control valves, and instruments filters debris as fluid flows left to right, with a removable cap for servicing, protecting downstream equipment.

Duplex designs with diverting valves allow servicing one basket while the other handles flow, ensuring uninterrupted service. The caption shows internal components, service access via the cover, and debris filtration.

Review valve and control valve design, selection, and sizing principles before proceeding to the next section to reinforce critical fundamentals for masterclass success.

Learn how a pneumatic control valve uses signal pressure and spring force to throttle flow, detailing its actuator, plug seating, trim, and stroke in regulating process variables.

Compare single port trim and double port trim in valves; single port creates unbalanced force on the plug, while double port reduces force but increases wear and sealing risk.

Understand the direction of action in control valves—air to close or air to open—and direct versus reverse acting, with instrument air failure prompting safe isolation of hydrocarbon lines.

Demonstrates dismantling a pneumatic control plug valve using a 3D model, detailing steps from unscrewing the packing adjuster to removing the plug valve body.

Dismantle a control valve using a 2d model, following the sequence from packing adjuster to valve body. Identify steps for removing packing, diaphragm, stem, spring, bonnet, yoke, and plug.

Master the design, selection, and sizing of valves and control valves, and ensure readiness before proceeding to the next section.

Explore process control valves used in steam and industrial fluids. Compare two-port and three-port configurations and review linear globe and gate valves, plus rotary ball, butterfly, and plug valves.

Globe valves enable throttling with a characteristic, featuring a body, bonnet, seat, disc, and stem. Compare single seat and double seat two-port valves, and examine differential pressure and actuator force.

Explore how control valve leakage is classified by closing state, with double-seat valves up to 0.1% (class three) and single-seat valves to 0.01% (class four).

Explore why single seat valves prevent leakage with tight shut-off, how closing forces grow with size, and how a piston balancing mechanism uses a balancing chamber to reduce actuation effort.

Explore slide valve designs—wedge gate and parallel slide—for isolating fluid with tight shut-off and low pressure drop; parallel slide enables automatic actuation for isolation or control.

Explore rotary type valves, including ball, butterfly, and plug valves, and how 90-degree operation, actuation, and flow characteristics support control, isolation, and full bore flow with minimal pressure drop.

Explore globe valve control options, including stem packing materials and configurations, friction, actuator force, and guidance methods like double guided and perforated plugs.

Explore the globe valve as the common two-port control valve for steam and liquids, highlighting easy activation and how two-port systems balance flows, with three-port valves for diverting or mixing.

three-port valves mix or divert by plug and seat arrangement; mixing uses two inlets and one outlet with a constant-volume AB port, while diverting uses one inlet and two outlets.

Three-port valves function as mixing or diverting valves in closed circuits, directing boiler water through or around the heat exchanger via ports A and B.

Master design selection and sizing for valve and control valve systems to prepare for the next section.

Learn how control valves adjust processes by changing flow rate and differential pressure, and how flow coefficients such as kv, kvs, kvr, Cv, and Ave relate to valve performance.

Explore the flow coefficient Cv and its Kv metric to express valve capacity and performance. Learn to convert Cv to Kv and calculate pressure drop for water and other fluids.

Apply the flow coefficient CV to assess the hydraulic performance of valves, fittings, and piping components, calculating an equivalent CV from known flow rate and differential pressure.

Solidify valve and control valve design selection and sizing concepts before advancing to the next section.

Explore how control valve trim shapes define flow characteristics, linking valve opening to orifice pass area and comparing fast opening, linear, and equal percentage types.

Explore fast opening valve characteristics, where a small lift triggers large flow changes, often yielding an on-off control that is electrically or pneumatically actuated.

Explore how linear characteristic valves tie valve lift to flow through a linear lift-pass area relation under constant differential pressure, as shown by a globe valve at 50% lift.

Explore equal percentage valves, where each lift increment increases flow by fixed percentage of the previous value, logarithmic relation described by an equation with V, E, theta, h, and VMAX.

Examine flow through an equal percentage control valve (range 50) at 40%, 50%, and 60% lifts with a 10 m3/h max under constant differential pressure.

Match the valve characteristic to the process by relating valve opening to flow, noting that linear valves suit water systems while equal percentage valves better fit steam systems.

Analyze a water circulating heating system with a three-port valve to maintain a constant flow rate and stable pressure loss, favoring a linear-characteristic valve.

Analyze a boiler water level control with a two-port feedwater valve, accounting for pump pressure drop and friction losses to size kv and kvr from the installation curve.

Construct the installation curve by plotting flow rate against the percentage of open pass area, note CVS 8.06 at full load, and select a valve larger than installation CVS.

Compare linear and equal percentage valves, using CVS, lift, and the installation curve to show how equal percentage valves offer better low-flow control and oversizing tolerance.

Modulate steam flow with a two-port control valve to regulate heat transfer in a steam-heated heat exchanger. Compute maximum load, steam flow, heat transfer area, and steam conditions across loads.

Assess the effects of oversized control valves on steam load control, contrasting linear and equal percentage valves with CVS 160 and differing curve shifts.

Master the design selection and sizing of valve and control valve components, and ensure you are prepared before proceeding to the next section of the masterclass.