Engineering Toolbox — RetubeCo Tools

Tube Weight

Weight of straight condenser / heat exchanger tubing from material, OD, wall, and length.

Measure OD across the tube; wall from the BWG gauge or a tube micrometer

Material Tube OD (in) Wall — BWG or inches Tube length Tube count

Tube ID & Gauge

Inside diameter and flow area from OD and BWG wall gauge.

Inside caliper jaws read bore directly; wall is half the OD−ID difference

Tube OD (in) BWG

Tube Rolling — Percent Wall Reduction

Apparent wall reduction from expanding a tube into a tubesheet. Measure the tube ID before rolling, the tubesheet hole ID, and the tube ID after rolling.

Roller expander thins the wall to lock the tube into the tubesheet

Tube OD (in) Tube wall (in) Tube ID before rolling (in) Tubesheet hole ID (in) Tube ID after rolling (in)

Typical rolled-joint specs call for roughly 4–8% apparent wall reduction depending on tube material and service — always follow the job specification or manufacturer's data sheet.

Tube-Side Velocity

Water velocity through the tubes from total flow, tube count, and passes.

Velocity rises with flow per tube and falls sharply with bore diameter

Total flow (GPM) Total tube count Passes Tube ID (in)

Common design guidance for condenser water is roughly 6–8 ft/s for steel and titanium, and 6–7 ft/s max for copper alloys to limit erosion — verify against the applicable spec.

Heat Transfer Surface Area

External tube surface area of a bundle.

External area of every tube between the tubesheets

Tube OD (in) Effective tube length Tube count

Log Mean Temperature Difference

LMTD for counterflow or parallel-flow exchangers.

LMTD averages the end temperature differences logarithmically

Flow arrangement Hot in (°F) Hot out (°F) Cold in (°F) Cold out (°F)

Heat Duty

Heat transferred to or from a flowing stream.

Duty is mass flow times specific heat times the temperature rise

Water (quick form)

Flow (GPM) Temperature rise ΔT (°F)

Any fluid

Mass flow (lb/hr) Specific heat c_p (BTU/lb·°F) ΔT (°F)

Thermal Expansion

Length change of tube, pipe, or structural members with temperature.

Growth scales with material coefficient, length, and temperature swing

Material Length Start temp (°F) End temp (°F)

Metal Weight

Weight of common stock shapes.

Cross-sectional area drives the weight for every stock shape

Shape Material Thickness (in) Width (in) Length Pieces

Cylinder & Tank Volume

Volume and water weight of a cylindrical shell or tank.

Bore area times length gives volume; water weighs 8.34 lb per gallon

Inside diameter (in) Length / height

Bolt Torque

Estimated tightening torque from the short-form torque equation T = K · D · F.

Torque converts to clamp load through the K factor — lubrication changes it sharply

Nominal bolt diameter (in) Target clamp load (lbf) Lubrication (K factor)

Estimate only — K varies widely with thread condition and lubricant. For pressure-boundary or critical joints, use the fastener manufacturer's or engineering-specified torque values.

BWG Tube Gauge Chart

Birmingham Wire Gauge wall thicknesses for condenser and heat exchanger tubing.

BWG	Wall (in)	Wall (mm)

Pipe Schedule Chart

Carbon steel pipe dimensions per ASME B36.10 (wall thickness in inches).

NPS	OD (in)	Sch 10	Sch 40	Sch 80

Fraction · Decimal · Millimeter

Every 64th from 1/64" to 1".

Fraction	Decimal (in)	mm

Material Properties

Typical values for common tube and fabrication materials.

Material	Density (lb/in³)	Density (lb/ft³)	Thermal exp. (μin/in·°F)

Typical room-temperature values for estimating; use certified material data for design work.

Unit Converters

Type in either field — the other updates.