insulation for tanks

8/3/2019 Insulation for Tanks

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GULBERG CONSULTING LIMITED 27 March 2011 Version 1.0

Portlaoise, Ireland

www.gulberg.eu

[email protected] Page 1 of 8

INSULATION OF TANKS IN PROCESS AND POWER INDUSTRY


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INTRODUCTION TO THIS DOCUMENT:

These instructions shall be used for guidance and information only. The correct and righteous installation of

insulation in process tanks presents difficulties of varying degrees, some relatively minor and others of more critical

nature.

DISCLAIMER:

This publication is intended as guidance only. The project specific installation documents should always be followed.

Gulberg Consulting Limited bears no liability and accepts no responsibility for eventual damage caused by incorrect

information in this publication.


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1. Insulation of tanks

1.1 Before progressing to insulation

-The primary supports should be welded on tank surface before tank leakage testing.

- The surface should be sand blasted, cleaned & dried.

- The surface to be painted with primer.

1.2 Tanks to be insulated

This guideline applies to site fabricated day and buffer tanks in tropical ambient conditions. This guideline covers

tanks diameters from 4000 mm to 15000 mm.

Design considerations

The insulation system is designed to take care of following forces.

-Weight of insulation system.

- Wind loads.

- Thermal expansion of tank and materials used

- Movements due to hydraulic forces in tank.

- Climatic

1.3 Insulation thickness

- Insulation thickness has to be calculated based on material temperature, vessel area and ambient

temperature in project area.

1.4 Insulation materials

Following materials shall be used for insulation.

Insulation

o Wired mats density 80 kg/m3

o Recommended size 900 4000 mm long

o Width should not exceed 1800 mm.

o Standard:- SFS 3976 M3.1

o PAROC 80VM

Cladding

o min 0.6 mm thick Galv Steel PVC coated

o

Recommended size 1050 height as per drawing.o Minimum depth of trough will be 25 mm.

o Standard:- SFS 3976 P5.

o Rannila RAN-35A, t=0.6, Pural, Colour: silver.

Supports

o Flat 100 5 for support cleats.

o Flat 30 3 for spacer ring & vertical support bar.

o For both Material S235JRG 2.


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Fastening

o Pop rivets Dia 3.2 mm to fasten cladding sheets to each other.

o Pop rivets Dia 4.8 mm to fasten cladding sheets to structure.

o Wire dia 0.5 mm Stainless steel to hold insulation in place.

o

Wire to sew the mats to each other (by insulation contractor).

Sealing

o Water proof sealing glue to close openings in cladding.

o Sealing tape to close opening in cladding.

o Sealing requirement to be decided & supplied by insulation

o Contractor.

1.5 Insulation procedure

The support cleats are welded to the tank surface before hydro or pressure testing. The support cleats are cut to size

100*100*10 from flat of 100*10, this cutting is done at site. The support cleats are welded horizontally along the

circumference at a pitch of 500 mm. The first row of support cleats shall be 100 mm from bottom. The distancebetween two rows of these support cleats depends on the width of mat selected, as a standard it is 900 mm.

The spacer ring is then welded to these support cleats. The spacer ring should have a gap of 5 mm at every 3000 mm

to provide for expansion. The gap can be provided in middle of two support cleats so that the unsupported part

doesnt exceed 250 mm. A vertical bar is welded to the spacer ring at approximately 3 m pitch.

The insulation mat is securely fit between spacer rings. It is then held in place by stainless steel wire tied between

two spacer rings at a pitch of 250 mm. The stainless wire should be also be tied between two vertical support bar at

a pitch of 250 mm. Due to the tying between vertical supports it provides some compressive force on mats.

Any spaces left between adjacent mats should be filled with mineral wool, and the ends of all the adjacent mats shallbe sewn with wire.

The insulation is to be started from bottom, so the last piece of mat under the roof overlap is to be cut to the

required width at site. The insulation will be covered with galvanized steel PVC coated cladding. The cladding shall be

trapezoidal with min depth of groove as 25 mm. The cladding shall be fastened to the spacer ring by rivets. The

cladding shall be riveted at each groove. The pitch however should not exceed 200 mm. The fastening shall be at

every spacer ring. Expansion joint is to be provided if cladding length exceeds 12 m. In such case the top cladding will

have a min overlap of 100 mm to prevent water.

The sheets shall be fastened to each other at this joint.

Overlap of 1 trough is considered between two adjacent cladding. The adjacent cladding shall be fastened to eachother at a pitch of 200 mm vertically. The nozzle and anchor chair penetrations in cladding can be done as shown in

figure 6. For electrical cable boxes the width shall be more than 150 mm so that they project out of the cladding. The

cladding shall have cut exactly of the same size of box. And this shall be sealed with glue or tape.

Plates shall enclose the level switches in tank design stage itself.


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1.6 Installation drawing and materials

Figure: Typical insulation system on Fuel oil tanks (1)


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Figure: Detail A, detail arrangement at tank bottom and tank top (2)


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Figure: Detail C, detail arrangement of the support system (3)

Figure: Detail F, detail of support cleat (4)

Figure: Detail of welding support cleat (5)


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Figure: Detail of nozzle insulation (6)

Figure: Detail arrangement at anchor chair (7)

insulation for tanks

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