Which of the following is the most widely used heat insulating material for pipelines carrying steam?

Which of the following is the most widely used insulating material for steam carray-ing pipelines?

A

Ceramic fibre blanket

B

Glass wool and 85% magnesia

C

Vermiculite

D

Slag wool

A steam carraying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will

A

Increase

B

Decrease

C

Remain unaffected

D

May increase or decrease; depends on the thickness of each layer

Pipelines carrying various utilities in chemical industries are identified by their colour codes. The color of pipeline carrying steam is

A

Black

B

Silver grey

C

Green

D

Yellow

Steam traps are provided in steam carrying pipelines to

A

Condense steam

B

Release excess steam pressure by bleeding steam

C

Remove condensate and inert gases

D

None of these

Pressure difference between two points in vessels, pipelines or in two different pipelines can be measured by a differential manometer. The pressure difference measured as the mm of water coloumn in case of mercury-water, differential manometer is equal to (where, H = difference in height of mercury column in mm).

A

H

B

12.6 H

C

13.6 H

D

14.6 H

Water hammer is caused in steam carrying pipelines, because of

A

Partial condensation of steam

B

Vibration of the pipeline

C

High degree of superheat of steam

D

Its exposure to torrential rain

An insulating refractory brick should have high porosity and low thermal conductivity. Which of the following is not used for inducing porosity in the insulating refractory bricks during its manufacture?

A

Cork

B

Saw dust

C

Sand

D

Chemically prepared foam

A steam pipe is to be lined with two layers of insulating materials of different thermal conductivities. For the minimum heat transfer,

A

The better insulation must be put inside

B

The better insulation must be put outside

C

One could place either insulation on either side

D

One should take into account the steam temperature before deciding as to which insulation is put where

A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place

A

The better insulation material should be put just next to pipe (i.e., inside)

B

The better insulating material should be put outside

C

Either of the insulating material could be put on either side

D

Steam temperature is considered before deciding as to which insulating material is to be put inside (i.e., just next to the pipe)

Gas carrying pipelines are best joined by

A

Nuts & bolts

B

Rivetting

C

Welding

D

None of these

Which of the following is the most widely used heat insulating material for pipelines carrying steam?

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