Jacketed Piping

TCE CONSULTING ENGINEERS LIMITED

SECTION: TITLE

DESIGN GUIDE FOR JACKETED PIPING

SHEET i OF iii

TCE.M6-ME-590-422


REV. NO.

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PPD. BY

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Sd/-

RUN

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Sd/-

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CHD. BY

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R3

DATE

11.09.1990

31.03.1997

02.05.2000

02.06.2003 TCE FORM NO. 020R2


SECTION: TITLE


SHEET i OF iii

TCE.M6-ME-590-422

FILE NAMES: M6ME422R3.DOC AND M6ME422R3.DWG

REV. NO.

R0

R1

R2

R3 ISSUE

INITIALS

SIGN.

INITIALS

SIGN.

INITIALS

SIGN.

INITIALS

PPD. BY

SVR

Sd/-

RUN

Sd/-

CSS

Sd/-

GC

CHD. BY

AMM

Sd/-

RVR

Sd/-

RVR

Sd/-

CSS

APD. BY

RVR

Sd/-

RL/MSK

Sd/-/Sd/-

RL

Sd/-

RL

SIGN.

R3

DATE

11.09.1990

31.03.1997

02.05.2000

02.06.2003 TCE FORM NO. 020R2


SECTION: CONTENTS

TCE.M6-ME-590-422


SHEET ii OF iii

CONTENTS

SL. NO.

TITLE

SH. NO.

1.0

SCOPE

1

2.0

JACKETED PIPING

1

3.0

JACKETED VALVES

2

4.0

LENGTHS OF HEATING SECTIONS

2

5.0

FLOW DIRECTIONS

3

6.0

BRANCHES

3

7.0

VENTS AND DRAINS

4

8.0

GENERAL

4

1.

JACKET AND CORE DIMENSIONS

5

2.

JACKET BLANK DIMENSIONS

5

3.

JUMPER LOCATION

6

4.


6

1.

SPACERS

7

2.

WELDING OF CORE AND JACKET PIPES

7

3.

JACKET BLANKS

7

FLANGE TYPES

8

5.

REDUCING FLANGE

8

6.

JUMPER

9

7.

INSTRUMENT STUB

9

8.

BRANCH INSTALLATION SEQUENCE

TABLES

FIGURES

4A, 4B & 4C

10 & 11

ISSUE R3 TCE FORM NO. 120 R1


SECTION: REV. STATUS

TCE.M6-ME-590-422


SHEET iii OF iii

REVISION STATUS

REV. NO.

DATE

DESCRIPTION

R0

11.09.1990

R1

31.03.1997

-Generally revised.

R2

02.05.2000

Generally revised.

R3

02.06.2003

Paras 2.0 and 6.1.9 revised, para 8.3 added and whole document reformatted.



SECTION: WRITE-UP

TCE.M6-ME-590-422

DESIGN GUIDE FOR JACKETED PIPING 1.0

SHEET 1 OF 11

SCOPE This design guide gives general recommendations to be followed for jacketed piping in chemical and industrial plants. Where process collaborator has furnished specific requirements, such specific requirements shall supersede requirements given in this guide. The guidelines given in the guide are based on pipe dimensions as per ASME B36.10.

2.0

JACKETED PIPING

2.1

Jacketed pipe constitutes a core pipe, which conveys the fluid, which needs to be heated or cooled by a heating or cooling medium flowing in the jacket pipe. Fluids flowing in the jacket may be steam, hot water, thermic fluid, chilled water and chilled brine etc.

2.2

Piping is required to be jacketed where a more efficient heat transfer than, what can be provided by tracing, or tracing with heat transfer cement, is required. Jacketed piping also provides uniform heat input around the circumference of the core pipe thus eliminating hot or cold spots that may cause degradation of fluid in the core pipe or localised freezing. Jacketed piping also provides closer and better temperature control. Requirements of jacketing are decided by the process or system engineer and are indicated in P and I Diagrams (P&I Ds).

2.3

Depending on the process requirement, the core and jacket materials can be the same or different. Also jacketing can be partial or full as dictated by the process requirements. Full jacketing may require jacketing of pipes, fittings and valves and specialities. Partial jacketing may require jacketing of only straight pipe with other items not jacketed or, in some cases, pipes and fittings fully jacketed but valves and specialities partially jacketed.

2.4

Jackets are broken into heating sections using flanged joints or jacket blanks. Adjacent jacket sections are connected by "jumper" pipes. Sizes of jumper pipes shall be as shown in P&I Ds, but generally are of 15 mm (1/2") for steam and 20 mm (3/4") for hot water or thermic fluids.

2.5

The jacket-core pipe size combinations shall be as stipulated by the process engineer. If there is no specific requirement, the combinations given in Table 1 can be considered.

2.6

Core pipe shall be supported and centered within the jacket pipe by spacers located at 120 degrees around the circumference and at intervals given in Table 1. Spacers are to be welded to core pipe. Spacer material shall be same as that of the core pipe. Refer Figure 1, for details. Grinding of spacer shall be done if necessary during fabrication of jacketed piping, to facilitate assembly. ISSUE R3 TCE FORM NO. 120 R1


SECTION: WRITE-UP

TCE.M6-ME-590-422


SHEET 2 OF 11

2.7

At locations of welds on core pipe, jackets shall be broken to permit examination of the welds. After successful examination of core pipe welds and completion of leak tests, the jacket shall be closed. Refer Figure 2. Degree of examination shall depend on the nature of fluid, pressure and temperature. This is to be decided in consultation with process engineer and as per the applicable code.

2.8

Fittings for core and jacket pipes shall be of butt welding type. Core elbows shall be of long radius type (R = 1.5D) and jacket elbows of short radius type (R = 1.0D). The jacket elbow may be split, if necessary, to facilitate assembly on core elbow. In some cases there may be interference between the elbows and it may be necessary to draw to scale and check for interference.

2.9

Blanks for jacketed piping shall be as shown in Figure 3. For dimensions, refer Table 2. Material of blanks shall be the same as that of the core pipe. Blanks are used to split the piping into various heated sections.

2.10

FLANGES

2.10.1

Unless the process demands otherwise, flange size for jacketed piping shall correspond to core pipe and the jacket connection at the flange shall be as shown in Figure 4.

2.10.2

When process demands that jacket be extended right up to the back of the flange, the jacket connection at the flange shall be as shown in Figure 5. Flanges shall be of reducing type i.e. jacket size X core size.

2.10.3

For sizes < 50 mm, where stainless steel core pipe is involved, stainless steel flanges may be used. For sizes > 80 mm, use either stainless steel stub ends with carbon steel lap joint flanges or carbon steel slip on flanges with SS liner. Refer Figures 4 and 5.

2.10.4

Where stub ends are used with reducing type flanges, lap diameter of stub end shall correspond to the jacket size.

2.11

At all flanged joints, jumpers shall also to be provided with flanged joints to facilitate disassembly. These shall be dimensioned as per Figure 6 and Table 3. Connections to jackets shall generally be radial. Tangential connections may be required in the case of Dowtherm heating to avoid formation of pockets.

3.0

JACKETED VALVES Unless process demands otherwise, jacketed valves shall be of core size and shall have partial jackets. If process requires full jackets, then valves shall be of core size and have flanges corresponding to jacket size. Heating or cooling medium connections shall be provided on the jacket. ISSUE R3 TCE FORM NO. 120 R1


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TCE.M6-ME-590-422


SHEET 3 OF 11

4.0


4.1

Lengths of heating sections shall generally limited to the values given in Table 4. When lengths beyond the values are involved, additional heating or cooling medium supply and return points shall be provided.

4.2

In the case of water, the above length is from the point of supply on the supply header to the point of return to the return header.

4.3

Wherever P&I D indicates requirements different from the above, follow the P&I D in consultation with the process engineer.

5.0

FLOW DIRECTIONS Steam or other heating vapour supply shall always be at the top of a heating section and condensate drained from the lower end of the section. In the case of liquid media, liquid shall enter at the bottom of a jacketed section and exit at the top for proper venting.

6.0

BRANCHES

6.1

INSTALLATION PROCEDURE

6.1.1

Install core pipe.

6.1.2

Move jacket section over core pipe.

6.1.3

Make cut in core pipe.

6.1.4

Weld branch to core pipe.

6.1.5

Move jacket branch over core branch pipe.

6.1.6

Check weld of core pipe. Leak test core pipe as per specified procedure.

6.1.7

Bring pipe section into alignment using spacers and weld to jacket. If necessary, use split jacket.

6.1.8

Weld branch jacket.

6.1.9

Check weld of jacket pipe. Leak test jacket pipe as per specified procedure. Refer Figure 8. ISSUE R3 TCE FORM NO. 120 R1


SECTION: WRITE-UP

TCE.M6-ME-590-422


6.2

SHEET 4 OF 11

INSTRUMENT CONNECTIONS Connections for pressure, temperature or flow measurement, made in core pipe shall be installed as per Figure 7. The jacket shall be locally swaged and welded to core pipe.

7.0

VENTS AND DRAINS

7.1

All high points on jacket shall be provided with threaded half coupling and plug for hydro test-purpose. Jumper connections can also be used for the purpose.

7.2

All low points on steam jacket shall be connected to a steam trap.

7.3

Core vents and drains shall be provided only if required by the process engineer.

8.0

GENERAL The following points shall be borne in mind while designing jacketed pipes if specifications are not available from the process collaborator.

8.1

Core pipe may be subject to external pressure due to fluid pressure acting in the jacket. The core pipe shall have adequate thickness to withstand the external pressure. Design shall be as per ASME Section VIII, Division 1.

8.2

If core and jacket pipes are of different materials (for example, stainless and carbon steels respectively) having different coefficients of thermal expansion, the assembly may give rise to column effect on the core pipe. This is to be checked.

8.3

It is not necessary that the core pipe and the jacket pipe be supported at the same location. Piping engineer shall consider this aspect while showing it clearly in the piping drawing, carrying out piping flexibility analysis and giving support data to civil engineer.

8.4

Flexibility analysis of jacketed piping may be carried out using programmes such as CAEPIPE or CAESAR II. If such a programme is not available, the following steps are suggested: (a)

First convert the jacket-core combination into an equivalent pipe having the combined moments of inertia of jacket and core pipes and an outside diameter same as the jacket pipe. Take the difference in modulii of elasticity between core and jacket materials into account.

(b)

Carry out flexibility analysis by conventional methods based on the equivalent pipe. ISSUE R3 TCE FORM NO. 120 R1


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TCE.M6-ME-590-422


SHEET 5 OF 11



SECTION: TABLE


SHEET 5 OF 11

TCE.M6-ME-590-422

TABLE 1 JACKET AND CORE DIMENSIONS (REFER FIGURE 1) CORE SIZE (in)

mm

JACKET SIZE mm (in)

SPACER INTERVALS

m

h

mm

25 (1)

40 (1.5)

2.0

3

40 (1.5)

50 (2)

-

-

50 (2)

80 (3)

3.0

8

80 (3)

100 (4)

4.0

6

100 (4)

150 (6)

4.5

19

150 (6)

200 (8)

5.0

17

200 (8)

250 (10)

5.5

20

TABLE 2 JACKET BLANK DIMENSIONS (REFER FIGURE 3) CORE SIZE mm (in)

JACKET SIZE mm (in)

BLANK INSIDE DIAMETER mm

BLANK OUTSIDE DIAMETER mm

25 (1)

40 (1.5)

36

Jacket OD+20

40 (1.5)

50 (2)

51

Jacket OD+20

50 (2)

80 (3)

63

Jacket OD+20

80 (3)

100 (4)

91

Jacket OD+20

100 (4)

150 (6)

117

Jacket OD+20

150 (6)

200 (8)

171

Jacket OD+20

200 (8)

250 (10)

222

Jacket OD+20



SECTION: TABLE


SHEET 6 OF 11

TCE.M6-ME-590-422

TABLE 3 JUMPER LOCATION (REFER FIGURE 6) JACKET DIAMETER mm (in)

DIMENSION L1 FOR JACKET FLANGE 150# mm

DIMENSION L1 FOR JACKET FLANGE 300# mm

40 (1.5)

185

220

50 (2)

200

230

80 (3)

215

250

100 (4)

240

270

150 (6)

275

310

200 (8)

295

335

250 (10)

325

365

TABLE 4 LENGTHS OF HEATING SECTIONS

HEATING OR COOLING MEDIUM

MAXIMUM RECOMMENDED LENGTH OF EACH HEATED OR COOLED SECTION, m

Steam

25 Core size ≤ 100 mm - 15

Thermic fluid (such as Dowtherm)

150 mm - 12 200 mm - 8

Hot or chilled water

30


Jacketed Piping

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