Insulation Thickness calculation of pipeINPUT Output

INPUT REQUIRED

30 303.15

40 313.15

120 393.15

802

k Thermal Conductivity of insulation at Mean Temp in W/m-C 0.038

L Length of pipe in mm 50000

D Actual OD of Pipe in mm 114.3 mm

90

For Horizontal Pipe use below formula

h 9.8

For Vertical Pipe use below formula

Surface ε A B

Aluminum, Bright Rolled 0.05 0.25 0.27

Aluminum, Oxidized 0.13 0.31 0.33

Steel 0.15 0.32 0.34

Galvanised Sheet Metal, Dusty Pipe Surface 0.44 0.53 0.55

Non Metalic Surfaces 0.95 0.85 0.87

For Carbon Steel Pipe Consider "A" 0.53

0C 0K

Ta Ambient Temperature in 0C

Ts Actual/Desire Insulation Surface Temperature Required in 0C

Th Bare Pipe Wall Temperature in 0C

Tm Mean Temperature in 0C(Th + Ts)

Refer Caltalouge of Insulation Material

ΔT Temp. difference between Bare pipe & Ambient (Th-Ta) in 0C

Calculate Surface Heat Transfer Coefficient in W/m 2-C

IF ΔT is less than 150 0C use below formula

W/m2-C

Refer Below Table for value of A & B

Note:

V Average Velocity of Air in m/s 2.77

h 22.28

Surface Thermal Resistance = 1/h 0.102

Use below given formula

0.816

Calculate Thickness of Insulation in mm

= 31 mm

Calculate Equivalent Thickness of Insulation for Pipe

Use below given formula

IF ΔT is more than 150 0C use below formula

The temperature must be enter in 0K 0K = 273.15 + 0C

Heat Transfer Coefficient in W/m2-0K

Calculate Surface Thermal Resistance in m 2- 0C/W

Rs m2-0C/W

Calculate Thermal Resistance of Insulation in m 2- 0C/W

Ri Thermal Resistance of Insulation in m2-0C/W m2-0C/W

tk Ri X k X1000

Where

= Radius of Pipe 57 mm

Equivalent Thickness of Insulation for Pipe 39 mm

Selected Insulation THK 40 mm

Calculate Heat Loss after insulation

First Calculate Surface Heat Transfer Coefficient after insulation

With Aluminum Cladding A = 0.31

3.6

A 30.48

Then use below formula to calculate Heat Loss in watts

H 1097.28 Watts

Note:

r1

Etk

hi W/m2-C

Surface Area of insulated Pipe in m2 m2

For Cold surface, Ts is to be substituted with Dew Point temperature Tdp

Type of Insulation MaterialInsulation Type Manufacturing Process Temp. Range Application Recommendations

Polystyrene

Polyurethane

Fiberglass Same as above

Calcium Silicate

An organic form made by polymerizing styrene -167 0C to 82 0C

Mainly used in cool rooms, refrigeration piping and concrete retaining structure.

Advantages: Rigid & Light weight.Disadvantages: Combustible, has low melting point, is UV degradable & susceptible to attacks by solvent

Made by reacting isocyanayes and alcohols. Made in continuous slab or foamed in situ.

-178 0C to 4 0C

Mainly used in cold room, refrigerated transports, deep freezing cabinates, refrigeration piping & floor and foundation insulation.

Advantages: Closed cell structure, low density and high mechanical strength.Disadvantages: Combustible, produces toxic vapours and has a tendecy to smoulder.

Rockwool (Mineral Fibre)

Manufactured by melting basalt and coke in a cupola at about 1500 0C. Phenolic binders used

Up to 820 0CMainly used to insulate industrial ovens, Heat Exchangers, Driers, Boiler & High Temperature Piping

Has wide density range& available in matts, blankets, loose form or preformed for pipe insulation. It is chemically inert, non-corrosive and maintains mechanical strength during handling

Formed by bonding glass fibres with thermo-setting resin. up to 540 0C

Will not settle or disintegrate with ageing Slightly alkaline PH9. Should not promote or accelerate the corrosion of steel, provided it is protected from external contamination.

Made from anhydrous calcium silicate material reinforced with a non-asbesros binder. Available in slab form of various sizes.

up to 1050 0CMainly used to insulate furnace walls, fire boxes, back-up refractory, flue lining and boilers

Has a minute air cell structure, low thermal conductivity and will retained in size & shape in its useable temp. range. Lightweight but good structural strength, it can withstand mechanical abrasion. It will not burn or rot, is moisture resistance & non-corrosive.

Ceramic Fibre

Made from high purity alumina & silica grains, melted in an electric furnace & blasted by high velocity gases inro light fluffy fibres. Made in a veriety of forms.

up to 1430 0C

Mainly used to insulate furnace & kiln back-up refractory, fire boxes, glass feeder bowls, induction coil insulation, high temperature gasket and wrapping material.

Suitable for many applications becouse of the varity of forms. These include cloth, felt, tape, coating cements and variform castable (fire brick)