Fittings, Flex, Dampers And Transitions
This batch adds practical field checks for joint ID, round duct parts, elbows, reducers, takeoffs, boots, flex, volume dampers, access for balancers, and control damper handoff.
Apprentice sees flanged duct and is unsure whether the joint is TDC/TDF/Ductmate, how the gasket should sit, and how to pull the duct faces into alignment without forcing the run crooked.
TDC, Ductmate, Flanges & GasketsSlip And Drive JointsGreen / Field Check · 1stApprentice sees a slip-and-drive/S-cleat joint and may not know which side gets the S, which side gets the drive, or why forcing it can rack the duct.
Spiral, Round Duct & CouplingsSpiral Vs Longitudinal-Seam RoundGreen / Field Check · 1stOrdering/cutting the wrong type; snaplock popping open
Spiral, Round Duct & CouplingsGored Vs Pleated ElbowsGreen / Field Check · 2ndWrong gore count/radius increases pressure drop or won't fit
Spiral, Round Duct & CouplingsConcentric Vs Eccentric Round ReducerGreen / Field Check · 2ndWrong type causes clearance or drainage/airflow issues
Spiral, Round Duct & CouplingsRound Couplings And Beaded SlipGreen / Field Check · 1stUnder-inserted joint, no screws, leaks or pulls apart
Spiral, Round Duct & CouplingsSupporting Round DuctYellow / Check First · 2ndSag, crushed pipe, band too loose or too tight
Spiral, Round Duct & CouplingsConical Vs Straight Taps On RoundGreen / Field Check · 2ndPoor airflow or leak if tap type/seal is wrong
Spiral, Round Duct & CouplingsCrimp End And Airflow DirectionGreen / Field Check · 1stAssembling against airflow so joints catch dust/leak
Spiral, Round Duct & CouplingsRound Volume DampersYellow / Check First · 2ndInstalled backward, no access, or blade not set for balancing
Cutting, Holes, Sleeves & PenetrationsTransition Slope LimitsYellow / Check First · 2ndToo-steep transition adds pressure drop/noise
Cutting, Holes, Sleeves & PenetrationsSquare Throat Elbows And Turning VanesYellow / Check First · 2ndMissing vanes, wrong single/double vane, noise/pressure
Cutting, Holes, Sleeves & PenetrationsRadius Elbows And R/W RatioGreen / Field Check · 2ndToo-tight radius increases loss; wrong for the space
Cutting, Holes, Sleeves & PenetrationsOffsets Around ObstaclesYellow / Check First · 2ndHitting steel/sprinkler; not enough clearance
Cutting, Holes, Sleeves & PenetrationsTees, Wyes, And CrossesGreen / Field Check · 2ndBullhead/backward branch, poor flow split
Cutting, Holes, Sleeves & PenetrationsRectangular Reducers And IncreasersGreen / Field Check · 2ndReducing on the wrong side hits equipment/coordination
Cutting, Holes, Sleeves & PenetrationsSpin-In Fittings To FlexGreen / Field Check · 1stLoose spin-in, unsealed, damper buried
Cutting, Holes, Sleeves & PenetrationsPlenum And Multiple TakeoffsYellow / Check First · 3rdHole layout wrong, weak plenum, leaks
Cutting, Holes, Sleeves & PenetrationsRound-To-Rectangular TransitionsGreen / Field Check · 2ndWrong orientation, poor fit, added loss
Cutting, Holes, Sleeves & PenetrationsTransitioning Around An ObstructionYellow / Check First · 3rdLosing area, over-restricting, or hitting structure anyway
Cutting, Holes, Sleeves & PenetrationsShop Fittings Vs Field FittingsGreen / Field Check · 1stField-making what should've been ordered; wasted time
Flex Duct, Boots, Collars & GrillesDiffuser Boots And Register BootsGreen / Field Check · 1stWrong size boot, no insulation, leaks at ceiling
Flex Duct, Boots, Collars & GrillesCollars And Starting CollarsGreen / Field Check · 1stUnsealed, loose, wrong diameter
Flex Duct, Boots, Collars & GrillesSaddle Tap Vs Cut-In TapYellow / Check First · 2ndOversized/rough hole, no seal, weakens trunk
Flex Duct, Boots, Collars & GrillesConical Branch TapsGreen / Field Check · 2ndStraight tap where conical was specced; more loss
Flex Duct, Boots, Collars & GrillesSupporting Boots And DropsYellow / Check First · 1stBoot resting on grid, cracked tile, sagging flex
Flex Duct, Boots, Collars & GrillesLaying Out Tap Holes On TrunkGreen / Field Check · 2ndHoles off-location, hitting seams/reinforcement
Flex Duct, Boots, Collars & GrillesBalancing Damper At TakeoffYellow / Check First · 2ndMissing damper so it can't be balanced; buried damper
Flex Duct, Boots, Collars & GrillesConnecting Flex To A CollarYellow / Check First · 1stInner liner not banded, insulation gap, kinked
Fire/Smoke Dampers, Rated Assemblies & AccessVolume Damper Blade And HandleGreen / Field Check · 1stHandle set opposite blade; balancer confused
Fire/Smoke Dampers, Rated Assemblies & AccessDamper Access For BalancersYellow / Check First · 2ndBalancer can't reach; access door missing
Fire/Smoke Dampers, Rated Assemblies & AccessLocking Quadrants And Set PointsGreen / Field Check · 2ndMoving a balanced damper and killing the air balance
Fire/Smoke Dampers, Rated Assemblies & AccessBackdraft And Gravity DampersGreen / Field Check · 2ndInstalled backward so it never opens/closes
Fire/Smoke Dampers, Rated Assemblies & AccessMotorized/Control Dampers HandoffYellow / Check First · 3rdActuator linkage wrong, wired by others, blade travel off
Flex Duct, Boots, Collars & GrillesFlex Length And Sag LimitsYellow / Check First · 1stToo-long/saggy flex kills airflow; excess used
Flex Duct, Boots, Collars & GrillesFlex Bend Radius And KinksYellow / Check First · 1stKinked flex chokes airflow; tight radius at boot
Flex Duct, Boots, Collars & GrillesSupporting Flex CorrectlyYellow / Check First · 1stNarrow strap pinches flex; sag between supports
Flex Duct, Boots, Collars & GrillesSealing Flex ConnectionsYellow / Check First · 1stUnsealed inner core leaks; insulation gap
Flex Duct, Boots, Collars & GrillesFlex Listing And Where It's AllowedRed / Stop And Verify · 2ndUsing non-listed/too-long flex where restricted
Flex Duct, Boots, Collars & GrillesWhen To Use Metal Instead Of FlexGreen / Field Check · 1stFlex where metal is required by spec/length
Flex Duct, Boots, Collars & GrillesFlex-To-Diffuser Neck FitGreen / Field Check · 1stMismatch causes leaks/restriction; forced connection