Process Equipment and Plant Design Practice Flashcards

A set of vocabulary flashcards based on typical process equipment and plant design exam questions, covering heat exchangers, distillation columns, pressure vessels, and piping components.

Fresh Water Pipeline Color

The color used to identify fresh water carrying pipelines in chemical industries is sea green.

Shear Modulus

The ratio of shear stress to shear strain.

25 Percent Cut Segmental Baffle

A baffle whose height is $75\%$ of the I.D. of the shell.

Lug Support

A support same as bracket support, provided usually for vessels of much smaller height than skirt supported vessels, and is most suitable for thick vertical vessels.

Elastic Limit

The stress developed in a material without any permanent set.

Tube Pitch

The shortest centre to centre distance between adjacent tubes in a heat exchanger.

Fouling Factor

A value that depends upon the characteristic of process fluid, suspended solids in the fluid, and the velocity of process fluid containing suspended solids.

Triangular Pitch Tube Layout

A tube layout in a shell and tube heat exchanger that permits the use of more tubes in a given shell diameter as compared to square pitch.

Conical Bottom Head Apex Angle

The typical apex angle for conical bottom heads used in chemical process equipments is $60^\circ$.

Factor of Safety

The ratio of the ultimate stress to the working stress.

HETP

Height Equivalent to a Theoretical Plate; the height of packing that will give the same separation as one theoretical plate in gas-liquid mass transfer operations.

Saturated Liquid Feed (q)

For a saturated liquid feed to a distillation column, the value of $q$ is 1.

Stuffing Box

A component used for the prevention of fluid leakage around moving parts.

Bubble Point Curve

The saturated liquid curve used in the Ponchon Savarit method enthalpy-concentration diagram.

Saddle Support

A type of support used for horizontal cylindrical vessels.

Skirt Support

The most suitable support for tall vertical vessels.

Nominal Size (Pipe)

An indication of the approximate diameter of a pipe.

Overall Tray Efficiency

The ratio of the number of ideal trays required to the number of real trays required in a distillation column.

Hoop Stress (Thin Cylindrical Vessel)

The circumferential stress induced in a thin walled cylindrical vessel under internal pressure, calculated as $\frac{pd}{2t}$.

Longitudinal Stress (Thin Cylindrical Vessel)

The stress induced in a thin walled cylindrical vessel under internal pressure equal to $\frac{pd}{4t}$, which is half the hoop stress.

Birmingham Wire Gauge (B.W.G.)

A number varying from 8 to 18 used to specify tube wall thickness.

Peclet Number (Plug Flow)

A Peclet number equal to $\infty$ is representative of plug flow.

Peclet Number (Complete Back Mixing)

A Peclet number equal to 0 is representative of complete back mixing.

Absorption Factor

The ratio of the slope of the operating line ($S_2$) to the slope of the equilibrium curve ($S_1$).

Poisson's Ratio

The ratio of unit lateral strain to the unit axial elongation within the elastic limit of a material.

Expansion Joint

A component provided in a pipeline to absorb contraction or expansion due to temperature changes.

Weep Holes

Holes provided in the plates of a distillation column to facilitate draining out liquid from a tray when the unit is not in operation.

Joint Efficiency (Seamless Pipe)

The joint efficiency ($J$) for a seamless pipe is 1.

LMTD Correction Factor ($F_T$)

The ratio of true temperature difference to the Logarithmic Mean Temperature Difference (LMTD) used in multi-pass shell and tube heat exchanger design.

Ligament

The clearance between two tubes in a shell and tube heat exchanger, with a minimum value of one fourth the outside diameter of the tube or 4.5 mm.