Process Equipment

1. Fresh water carrying pipelines in chemical industries are coloured with _______ color.

a. sea green

b. brown

c. yellow

d. red

a. sea green

Which of the following material is seldom used for pressure vessel construction ?
a. Rimmed still

b. Mild steel

c. Killed steel

d. Semi-killed steel

a. Rimmed still

The ratio of shear stress to shear strain is called

a. bulk modulus
b. shear modulus

c. modulus of rigidity

d. modulus of elasticity

b. shear modulus

4. 25 per cent cut segmental baffle means that the baffle
a. height is 75% of the I.D. of the shell.

b. height is 25% of the I.D. of the shell.

c. spacing is 75% of its height.

d. width is 25% of its height.

a. height is 75% of the I.D. of the shell.

5. Liquid/petroleum fuel storage tanks are built underground (as in case of petrol pumps), when the storage capacity is less than ______ kilolitres.

a. 20

b. 30

c. 45

d. 85

c. 45

a. 10

b. 25

c. 75

d. 300

d. 300

Lug support is

a. the most suitable for thick vertical vessel.

b. same as bracket support.

c. provided usually for vessels of much smaller height than skirt supported vessels.

d. all (a), (b) and (c).

d. all (a), (b) and (c).

8. Pick out the wrong statement pertaining to the use of valve tray, seive tray and bubble cap trays in continuous distillation column.

a. Bubble cap trays though most expensive are the best in situations, where low vapour rates is to be handled and a positive liquid seal is essential at all flow rates.

b. Murphree efficiency of all the three trays are nearly equal, however the peak efficiency is generally higher for seive and valve trays than the bubble cap.

c. Maintenance cost for valve and seive trays are comparatively more than bubble cap tray due to their relatively complicated construction features.

d. Valve trays have the highest turn down ratio (i.e. the ratio of the highest to the lowest vapour flow rates) and thus provides the maximum flexible operating range.

c. Maintenance cost for valve and seive trays are comparatively more than bubble cap tray due to their relatively complicated construction features.

With increase in the number of shell passes, the value of FT

a. increases

b. decreases

c. remains same

d. remains same, only if the number of tube passes does not change.

a. increases

10. Holes of a sieve tray are arranged in triangular pitch of __________ times the hole diameter.

a. 1.5 to 2

b. 2.5 to 5

c. 5 to 10

d. 10 to 15

b. 2.5 to 5

The stress developed in a material without any permanent set is called the

a. ultimate stress

b. yield stress

c. elastic limit

d. breaking stress

c. elastic limit

In a shell and tube heat exchanger, the 'tube pitch' is defined as the

a. O.D. of the tube for square pitch.

b. shortest distance between two adj acent tube holes.

c. shortest centre to centre distance between adjacent tubes.

d. none of these.

c. shortest centre to centre distance between adjacent tubes.

Which of the following is not a valid assumption in continuous binary distillation for calculating the number of equilibrium stages by Mc-Cabe-Thiele's method ?

a. Sensible heat changes for vapour & liquid are negligibly small.

b. Reflux is not a saturated liquid.

c. Molar latent heat of the two components are equal.

d. Heat of mixing of normal liquid is assumed to be zero.

b. Reflux is not a saturated liquid.

15. Overall distillation column efficiency for most of the refinery columns can be given by (for μ = 0.07 - 1.4 cp and relative volatility < 4) (where η = overall column efficiency, % μ = molal average viscosity of feed at average column temperature and pressure, cp Δp = pressure drop per tray, psi)

a. η = 17 - 61.1 log μ

b. η = 24.6 dP/ μ

c. η = 1.66 - 0.25 log μ

d. η = 0.25 log μ - 1.67

a. η = 17 - 61.1 log μ

Tube side pressure drop in a 1-2 heat exchanger (for turbulent flow of fluids through the tubes) is about __________ times, that in a 1-1 heat exchanger having the same size & number of tubes and operated at the same liquid flow

rate.

a. 2

b. 1/2

c. 4

d. 8

d. 8

To keep the power input constant for a stirred vessel operating under fully developed turbulent flow conditions (constant power number), if the impeller diameter is increased by 20%, the impeller speed should be decreased by a factor of

a. (1.2)^3/2

b. (1.2)^3/5

c. (1.2)^2/3

d. (1.2)^5/3

d. (1.2)^5/3

11. In case of a shell and tube heat exchanger, the minimum shell thickness for carbon steel (inclusive of corrosion allowance) depends on shell diameter and is in the range of __________ mm.

a. 3-5

b. 5-11

c. 8-15

d. 12-18

b. 5-11

The value of fouling factor depends upon the

a. characteristic of process fluid.

b. velocity of process fluid containing suspended solids.

c. suspended solids in the fluid.

d. all (a), (b) and (c).

d. all (a), (b) and (c).

In case of bubble cap distillation column of diameter greater than 1.2 metres, the cap diameter is roughly about __________ cms.

a. 10

b. 20

c. 30

d. 35

a. 10

In a heat exchanger, shell side fluid velocity can be changed by changing

the tube

a. layout

b. pitch

c. both (a) & (b)

d. neither (a) nor (b)

c. both (a) & (b)

21. Where does the maximum tensile strength occur in a thick cylindrical vessel subjected to internal pressure ?
a. At the inner surface.

b. At the mid thickness of the cylindrical wall.

c. At the outer surface.

d. None of these.

a. At the inner surface.

22. It is not desirable to design a heat exchanger for LMTD correction factor, FT, of less than

a. 0.99

b. 0.95
c. 0.80

d. 0.55

c. 0.80

rivetted joint does not fail by __________ of rivets.

a. tearing

b. shearing

c. tearing of the plate across a row
d. none of these

d. none of these

Triangular pitch tube layout as compared to square pitch in a shell and tube heat exchanger

a. permits the use of less tubes in a given shell diameter.

b. facilitates comparatively easier external cleaning because of large clearance.
c. permits the use of more tubes in a given shell diameter.

d. both (b) and (c).

c. permits the use of more tubes in a given shell diameter.

Bracket supports are the most suitable for supporting __________ vessels.
a. thick walled vertical

b. horizontal

c. thin shperical (e.g. Horton sphere)

d. none of these

a. thick walled vertical

In a multipass shell and tube heat exchanger, the shell side cross flow area does not depend upon

a. baffle spacing

b. clearance

c. pitch
d. none of these

d. none of these

Two iron pipes of the same nominal diameter but different schedule numbers will have the same

a. inside diameter

b. outside diameter

c. wall thickness

d. none of these

a. inside diameter

Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about __________ kcal/hr.m2.°C.

a. 1250

b. 2500

c. 7500

d. 15000

c. 7500

Pick out the wrong statement

a. For all the cylindrical process vessels operating above atmospheric pressure, formed heads are used for closing the vessel.

b. Fouling factor of river water is less than that of sea water.

c. Risers provided in bubble cap trays in the distillation column facilitate the flow of both liquid and vapor.

d. both (b) and (c).

d. both (b) and (c).

Lessing ring is formed by the addition of a partition across the centre of a raschig ring, which results in an area increase of about __________ percent.

a. 5

b. 20

c. 35

d. 55

b. 20

In chemical process equipments, the conical bottom heads used, usually has an apex angle of

a. 20°

b. 40°

c. 60°

d. 80°

c. 60°

Smaller sized packings are generally dumped to the packed columns, and the large ones of size greater than __________ mm are stacked individually, which provides better control over bed porosity and offers lower gas pressure drop.

a. 25

b. 50

c. 75

d. 150

c. 75

Shell side heat transfer co-efficient in case of square pitch as compared to the triangular pitch under similar condition of fluid flow and tube size is

a. more

b. same

c. less

d. twice

c. less

Correct use of 'factor of safety' is very important in equipment design. It is defined as the ratio of the

a. ultimate stress to breaking stress.

b. ultimate stress to working stress.

c. working stress to ultimate stress.

d. none of these.

b. ultimate stress to working stress.

The operating velocity in the absorption tower is usually 40-50% of the flooding velocity. Packed absorption towers are normally designed for a pressure drop of about __________ mm of water column per metre height of packing.

a. 1-5

b. 20-40

c. 100-150

d. 1000-1500

b. 20-40

__________ tray arrangement is recommended for distillation column having diameter upto 4 ft.

a. Radial flow

b. Cross flow

c. Split flow

d. Cascade

b. Cross flow

What is the value of 'q' for saturated liquid feed to a distillation column ?

a. 0

b. <1

c. 1

d. >1

c. 1

In perforated plate towers, the

a. hole sizes may be around 1/8" or 3/16".

b. total hole area may be around 6 to 15% of tower cross-sectional area.

c. pressure drop is less compared is similar bubble cap towers.

d. all (a), (b) and (c).

d. all (a), (b) and (c).

The main purpose of providing stepping on the trays is to

a. increase the residence time.

b. decrease the pressure drop.

c. facilitate handling of large flow rate of liquid.

d. improve the flow condition.

c. facilitate handling of large flow rate of liquid.

The operating pressure drop range in a bag filter is about __________ mm water gauge.

a. 50-150

b. 5-10

c. 500-1500

d. 1500-2500

a. 50-150

The ends of a cylinderical vessel can be closed by a head, which can be one of the four shapes. For the same thickness, choose the one which can withstand the highest pressure.

a. Flat plate

b. Hemispherical

c. Torispherical

d. Ellipsoidal

d. Ellipsoidal

For laminar flow (NRe < 2100) in steel pipe, the optimum inside pipe diameter is given by

a. Di, opt = 3 Q^0.36 x ρ^0.18

b. Di, opt = 3.9 Q^0.45 x ρ^0.23

c. Di, opt = 7.6 Q^0.36 x ρ0.9

d. Di, opt = 3 Q^0.36 x ρ^1.86 x μ^0.08

a. Di, opt = 3 Q^0.36 x ρ^0.18

Pick out the correct statement.

a. When highly corrosive fluids are to be handled, the plate towers prove to be cheaper and easier to construct than packed tower.

b. Packed towers are generally preferred over plate towers, if the liquids have a foaming tendency.

c. The pressure drop through the packed towers is generally more than the pressure drop through plate towers designed for same duty.

d. none of these.

b. Packed towers are generally preferred over plate towers, if the liquids have a foaming tendency.

Wall thickness of schedule 40 pipe as compared to that of schedule 80 pipe is

a. more

b. less

c. same

d. cither (a) or (b); depends upon the I.D. of the pipe

b. less

Pick out the wrong statement pertaining to the design of a basket type evaporator.

a. It is used for high viscosity liquor having large rate of scaling.

b. The tube bundle is suspended on bracket.

c. There is no central downtake.

d. Downtake is formed by the annular space between the bundle and the shell.

a. It is used for high viscosity liquor having large rate of scaling.

Pick out the wrong statement pertaining to the design of the bubble cap tray of a distillation column to give stable operation and even vapour distribution.

a. The pressure drop due to the caps & slots and the static submergence should be as high as practicable for reasonable operation.

b. Tendency towards stable operation is increased by increasing the skirt clearance of the caps, lowering the rate of liquid flow per unit plate width or increasing the spacing between the caps.

c. The dimensionless ratio of liquid gradient to pressure drop head caused by the bubble cap assembly should be less than 0.4.

d. none of these.

d. none of these.

Speed of the drum of the rotary vacuum filter normally ranges from __________ rpm.

a. 0.1 to 2

b. 5 to 7

c. 3 to 8

d. 8 to 15

a. 0.1 to 2

stuffing box is used for

a. absorbing the contraction/expansion of pipeline due to temperature changes.

b. prevention of fluid leakage around moving parts.

c. facilitating smooth opening and closing of a valve.

d. reducing the resistance of fluid flow.

b. prevention of fluid leakage around moving parts.

Pressure drop (Δp) and the superficial gas mass velocity (G) in case of packed absorption tower operating in the preloading range are related as

a. Δp = G

b. Δp = G^0.5

c. Δp = G^2

d. Δp = 1/G^0.6

c. Δp = G^2

Pick out the wrong statement. In an agitated vertical cylinderical reaction vessel, the

a. ratio of liquid depth to tank diameter (i.e. the filling ratio) recommended for most purposes is 1.

b. filling ratio for dispersing gas in a liquid is 2 for sufficiently long contact period.

c. flat bottom and conical bottom vessels have low agitation efficiency for agitation of heavy solids in liquids.

d. dished bottom vessel has very high power consumption.

d. dished bottom vessel has very high power consumption.

Needle valves are generally not used for

a. very large diameter pipes.

b. high pressure throttling service.

c. very accurate flow control.

d. smaller sizes of pipe.

a. very large diameter pipes.

Height equivalent to a theoretical plate (HETP) is the height of packing that will give the same separation as one theoretical plate in gas-liquid mass transfer operations like distillation, absorption/stripping and humidification/dehumidification. HETP which is experimentally determined, depends upon the

a. flow rates of each fluid.

b. type and size of packing.

c. concentration of each fluid.

d. all a, b & c.

d. all a, b & c.

Pick out the wrong statement.

a. Safety valves are provided in heat exchangers for removal of non conden-sables.

b. Liquid metals and dowtherm are used for very high temperature heating.

c. In a shell and tube heat exchanger, high pressure fluid is generally routed through the tube.

d. A loop seal or U-seal is provided in a vertical condenser sub-cooler to prevent quick draining of the condensate.

a. Safety valves are provided in heat exchangers for removal of non conden-sables.

With increase in gas flow rate to fabric surface area ratio (Nm3/hr/m2 fabric surface area), the size & the cost of a bag filter

a. increases

b. decreases

c. remain unaffected

d. none of these

b. decreases

. A head comprises of straight flange section, corner torus, section and central dished section. Crown radius and knuckle radius in a head is related respectively to the

a. central dished section and corner torus section.

b. corner torus section and central dished section.

c. central dished section and straight flange section.

d. straight flange section and corner torus section.

a. central dished section and corner torus section.

Number of evaporators which can be used in service in a multiple effect evaporation system is limited by the

a. practical limit reached, due to low heat transfer rate because of inadequate temperature difference.

b. economic limit reached, when the plant cost exceeds the saving of steam.

c. both (a) & (b).

d. neither (a) nor (b).

c. both (a) & (b).

Which of the following is used to set the diameter of the distillation column?

a. Number of theorectical plates.

b. Static submergence.

c. Allowable vapour velocity.

d. Length of straight rectangular weir on cross-flow tray.

c. Allowable vapour velocity.

Ponchon Savarit method is based on the use of enthalpy concentration diagram, which contains the bubble point curve (saturated liquid curve), dew point curve (saturated vapour curve) and equilibrium tie lines. As compared to McCabe-Thiele's method, this method

a. is more accurate in finding the number of equilibrium stages.

b. accounts for the enthalpy changes in the process.

c. facilitates direct calculation of heat load on reboiler & condenser from, the diagram used in this method.

d. all 'a', 'b' & 'c'.

d. all 'a', 'b' & 'c'.

The optimum size ratio for two mixed reactors in series depends on the kinetics of the reaction and the conversion level. For reaction orders more than one, the

a. equal sized reactors are the best.

b. smaller reactor should come first.

c. larger reactor should come first.

d. none of these.

b. smaller reactor should come first.

In a shell and tube heat exchanger, tube side __________ of the mass velocity.

a. heat transfer co-efficient is proportional to 0.8th power

b. pressure drop is proportional to the square

c. both 'a' & 'b'

d. neither 'a' nor 'b'

c. both 'a' & 'b'

Which of the following is not a graphical method (but is an analytical method) for the calculation of theoretical number of stages in case of continuous binary distillation?

a. Sorel-Lewis method.

b. McCabe-Thiele's method.

c. Ponchon-Savarit method.

d. none of these.

a. Sorel-Lewis method.

Saddle supports are used for supporting __________ vessels.

a. horizontal cylinderical

b. tall vertical

c. thick walled vertical

d. thick spherical

a. horizontal cylinderical

The diameter of a propeller agitator used in agitation tank ranges from __________ percent of the tank diameter and its peripherial speed is normally 300 to 500 metres/minute.

a. 5 to 10

b. 15 to 30

c. 40 to 50

d. 55 to 75

b. 15 to 30

In packed towers provided with saddle packing, liquid redistributors are positioned at every __________ times column diameter or 6 metres whichever is less.

a. 2-3

b. 5-8

c. 10-15

d. 20-25

b. 5-8

Optimum reflux ratio in a continuous distillation column is determined by the

a. maximum permissible vapour velocity.

b. flooding limit of the column.

c. total cost consideration (fixed cost of the column plus the cooling water & steam cost).

d. none of these

c. total cost consideration (fixed cost of the column plus the cooling

water & steam cost).

Cooling water fouling factors vary in the range of 0.001 to 0.003

a. (BTU/hr.ft2 . °F)^-1

b. (kcal/hr.m2 .°C)^-1

c. (W/m2.°K)^-1

d. (kcal/hr. m. °C)^-1

a. (BTU/hr.ft2 . °F)^-1

Minimum recommended baffle spacing in a shell and tube heat exchanger is about (where, D = shell diameter )

a. 0.2 D

b. 0.5 D

c. 0.66 D

d. 0.80 D

a. 0.2 D

The maximum liquid gradient over a tray must not exceed

a. 0.5" -1.25".

b. 2"-3.5".

c. 5".

d. half the tray spacing.

a. 0.5" -1.25".

An underdesigned steam trap will

a. waste steam.

b. destroy itself of acceleration wear due to rapid recycling.

c. back up condensate and cause water hammer in steam line.

d. none of these.

c. back up condensate and cause water hammer in steam line.

The slope of the feed line in distillation opeartion is given by (where, q =

fraction of the feed stream that is liquid.)

a. -q

b. -q/(1-q)

c. -q/(q-1)

d. none of these

b. -q/(1-q)

Speed of industrial paddle agitator ranges from __________ rpm.

a. 1 to 5

b. 20 to 100

c. 500 to 750

d. 1000 to 2000

b. 20 to 100

__________ strain is measured using a 'strain rosetter'.

a. Volumetric

b. Shear

c. Linear

d. none of these

c. Linear -should be shear strain

Thin spherical shells subjected to internal pressure, develop __________ stresses.

a. radial

b. circumferential

c. both (a) & (b)

d. neither (a) nor (b)

a. radial

With increase in the reflux ratio for a fixed production from a continuous

binary distillation column, the __________ decreases.

a. fixed charges initially

b. running cost of cooling water for condenser

c. vapour & liquid load both

d. running cost of steam for reboiler

a. fixed charges initially

The slope of operating line in the rectifying section of a distillation column is unity, if the reflux ratio is

a. 0

b. ∞

c. 1

d. minimum

b. ∞

Vertical vessels are not supported by

a. brackets

b. skirts

c. columns

d. saddles

d. saddles

With increase in pressure drop (for a given particle size), the dust collection efficiency of a cyclone separator will

a. increase

b. decrease

c. remain unaffected

d. increase or decrease depending on the nature of the dust.

a. increase

. Spherical shaped pressure vessel is considered to be the most ideal, because it can

a. withstand higher pressure for a given metallic shell thickness.

b. be fabricated very easily.

c. be designed without wind load considerations.

d. be supported very easily.

a. withstand higher pressure for a given metallic shell thickness.

An adequate clearance between the tray and the shell wall of a distillation column is provided to

a. drain the liquid from the tray when the unit is not in operation.

b. allow for thermal expansion and facilitate installation.

c. avoid back-trapping.

d. none of these.

b. allow for thermal expansion and facilitate installation.

Overall tray efficiency of a distillation column is the ratio of the number of

a. overall gas transfer units to the number of ideal trays required.

b. ideal trays required to the number of real trays required.

c. real trays required to the number of ideal trays required.

d. none of these.

b. ideal trays required to the number of real trays required.

Pick out the wrong statement about the design of a sieve plate column.

a. An increased weir height improves the tray efficiency at the cost of high plate pressure drop; optimum wear height being 40-90 mm for column pressure above atmospheric and 6-12 mm for vacuum columns.

b. For segmental downcomers, the chord length is 60-80% of the column diameter. An initial value of downcomer area of 12% is taken in the design.

c. Width of the calming section provided at the inlet and outlet sides of the plate is 75 mm for column diameter below 1.5 metres and 100 mm for larger diameter columns.

d. Minimum recommended downcomer residence time for the disengagement of entrained vapour is the same for both foaming and non-foaming liquids, which is about 20 seconds.

d. Minimum recommended downcomer residence time for the disengagement of entrained vapour is the same for both foaming and non-foaming liquids, which is about 20 seconds.

Generally, no corrosion allowance in wall thickness of a part is required, if

the thickness is more than __________ mm.

a. 10

b. 20

c. 30

d. 5

c. 30

Multiple blade paddle agitator is used for mixing high viscosity liquids/paste in which the paddle diameter is commonly 0.8 times the tank diameter. However, the width of the blade is in the range of __________ times the paddle diameter.

a. 0.1 to 0.25

b. 0.3 to 0.5

c. 0.5 to 0.6

d. 0.65 to 0.80

a. 0.1 to 0.25

In a __________ rivetted joint, the rivets in the various rows are opposite to each other.

a. zig-zag

b. chain

c. diamond

d. none of these

b. chain

Pick out the wrong statement:

a. The tensile strength of a brittle material is less than its compressive strength.

b. The compressive strength of a ductile materia] is less than its tensile strength.

c. In a thick cylindrical shell, the hoop stress is maximum at the inner radius.

d. The value of crushing load is more than that of buckling load for long colmns.

d. The value of crushing load is more than that of buckling load for long colmns.

Generally, elliptical dished heads

a. are manufactured on 2:1 ratio of major to minor axis and is recommended to be used for pressure vessels operating above a pressure of 1.5 MN/m2 .

b. resist half the pressure rating compared to hemi spherical head provided on the cylindrical shell of the same thickness and diameter.

c. are approximately as strong as seamless cylindrical shell having the corresponding I.D and O.D.

d. all (a), (b) and (c)

d. all (a), (b) and (c)

Pick out the wrong statement pertaining to the comparative evaluation of performance of the packed tower and the plate tower.

a. Plate tower is perferred, if interstage cooling is required to remove heats of reaction or solution.

b. Plate tower is preferred over packed tower, if the operation involves liquids containing dispersed solids.

c. The total weight of a dry plate tower is usually much more than that of a dry packed tower designed for the same duty.

d. In operations involving large temperature changes. (e.g. distillation), plate towers are preferred over packed towers as

c. The total weight of a dry plate tower is usually much more than that of a dry packed tower designed for the same duty.

The circumferential (hoop) stress in a thin walled cylinderical vessel under internal pressure is

a. pd/2t

b. pd/4t

c. pd/t

d. pd/3t

a. pd/2t

a. much more than that for fully open globe valves.

b. much less (say 2% than that for fully open globe valves).

c. around 7.

d. both (b) and (c).

d. both (b) and (c).

. LMTD correction factor is used in heat exchanger design for

a. double pipe heat exchanger.

b. multipass shell and tube heat exchanger.

c. fouling fluids.

d. counter flow of hot and cold fluids.

b. multipass shell and tube heat exchange

. Floating head heat exchangers are used for the

a. heat transfer between corrosive fluids.

b. cases where temperature difference between the shell and the tubes is more (>50°C).

c. co-current heat transfer systems.

d. counter-current heat transfer systems.

b. cases where temperature difference between the shell and the tubes is more (>50°C).

The most common standard size of bubble caps used in industrial operation

is

a. 1" dia cap with 0.5" dia riser.

b. 6" dia cap with 4" dia riser.

c. 8" dia cap with 1" dia riser.

d. 4" dia cap with 8" dia riser.

b. 6" dia cap with 4" dia riser.

Compensation against openings in process vessels for giving inlet and outlet connections, for providing sight glasses and manholes etc. is provided for strength and rigidity. The most efficient type of compensation is of __________

type.

a. nozzle or rim

b. flared out

c. fluid in

d. ring plate

a. nozzle or rim

In case of a continuous distillation column, increase in reflux ratio may result in the

a. lower fixed charges for the column.

b. greater cost for the reboiler heat supply.

c. greater cost for the condenser coolant.

d. all (a), (b) and (c).

d. all (a), (b) and (c).

In a distillation column, the minimum residence time for liquid in the downspout is about __________ seconds.

a. 1

b. 8

c. 80

d. 180

b. 8

Thickness of the frame of a plate and frame filter as compared to that of plates is

a. less

b. same

c. more

d. either (a) or (b)

c. more

Which of the following factors affect the pressure drop in a co-current gas liquid absorption packed tower ?

a. Size, shape, orientation and surface of the packing particles.

b. Density and viscosity of fluids.

c. Fluid flow rates.

d. All (a), (b) and (c).

d. All (a), (b) and (c).

The thickness of heat transfer plates used in the plate type heat exchanger ranges from __________ mm, pressed in a single piece provided with grooves & corrugations.

a. 0.3 to 0.8

b. 1.25 to 3.125

c. 3.5 to 7.0

d. 8-12

b. 1.25 to 3.125

. Rivets are generally specified by the

a. head diameter

b. shank diameter

c. overall length

d. none of these

b. shank diameter

Length to diameter ratio of most rotary driers is in the range of

a. 1 to 2

b. 4 to 10

c. 10 to 20

d. 20 to 30

b. 4 to 10