MAN B&W
7.07
Page 6 of 9
MAN Diesel
MAN B&W ME-GI TII engines
198 86 37-7.2
Inner pipe
The inner pipe in double-wall gas piping for deliv-
ery of high-pressure gas to the ME-GI main en-
gine has the following specification:
Design pressure: .........................................320 bar
Temperature range: ......................÷55 ºC to +60 ºC
Total pressure loss (max) *): ............................5 bar
LHV: .......................................................... 50 MJ/kg
*) This refers to pressure loss from FGS flange to
engine flange and only due to piping.
Design calculations for the pipe are performed
using the above design assumptions, using the
formula specified in chapters 5.2 and 5.3 of the
IGC code for calculation of pipe thickness. Pipe
strength for different pipe sizes is selected based
on manufacturers information according to ASME
B31.3.
For projects using gas with a specific LHV, the
maximum total pressure loss requirement is un-
changed, so a larger diameter pipe will be required
to maintain pressure loss with a higher flow.
Total pressure loss
The total pressure loss from gas supply system to
ME-GI main engine should be as low as possible,
and calculated by the shipyard, where by:
P
Total
= P
Piping
+ P
GVT
+ P
Filter
+ P
Flowmeter
According to FGS design a maximum of 15 bar is
allowed at 100 % SMCR. However, this requires
additional energy from the FGS system so it is
more desirable to improve the installation to re-
duce pressure loss to a minimum.
Material
The recommended material is Duplex EN 1.4462
up 1½” pipe dimension and Super Duplex EN
1.4410 up to 2½” pipe dimension.
Selection of this material is based on corrosion
resistance, required strength, resistance to cold
exposure, resistance to stress corrosion chloride
cracking. Therefore long maintenance intervals
can be offered with this material.
Piping should be cold-worked in order to reduce
internal surface roughness.
Maximum surface roughness: ..................... 15 μm
Sizing of inner pipe
In order to dimension the piping, the guidelines
provided in the table below can be used.
The pressure loss is calculated based on a length
(stated in metres in the tables below) of piping
from Fuel Gas Supply to the main engine inlet
flange, including 20 bends.
Design using welded bends is recommended,
with minimum radius as per DIN 13480-3, Chapter
6.2 and 6.3.
Dimension guidelines based on standard pipe sizes for EN 1.4410
Power
range
Max
flow
Pipe
OD
t
SCH
NPS
DN
Test
pressure
Pressure loss
50m
100m
200m
MW
Kg/h
mm
mm
inch
bar
bar
45-80
11,800
60.33
5.54
80
2
50
480
1.4
2.6
5.0
t
80
19,000
73.03
7.01
80
2½
65
480
1.5
2.7
5.0
Dimension guidelines based on standard pipe sizes for EN 1.4462
Power
range
Max
flow
Pipe
OD
Thick-
ness, t
SCH
NPS
DN
Test
pressure
Pressure loss
50m
100m
200m
MW
Kg/h
mm
mm
inch
bar
bar
0-15
2,100
33.40
3.88
40
1
25
480
1.5
2.5
4.7
15-30
4,000
42.16
4.85
80
1¼
32
480
1.4
2.6
5.0
30-45
6,000
48.26
5.08
80
1½
40
480
1.4
2.5
4.9
Summary of Contents for S65ME-C8.2-GI-TII
Page 4: ......
Page 10: ......
Page 11: ...MAN B W MAN Diesel Engine Design 1...
Page 12: ......
Page 29: ...MAN B W MAN Diesel Engine Layout and Load Diagrams SFOC 2...
Page 30: ......
Page 53: ...MAN B W MAN Diesel Turbocharger Selection Exhaust Gas By pass 3...
Page 54: ......
Page 58: ......
Page 59: ...MAN B W MAN Diesel Electricity Production 4...
Page 60: ......
Page 100: ......
Page 101: ...MAN B W MAN Diesel Installation Aspects 5...
Page 102: ......
Page 136: ......
Page 145: ...MAN B W MAN Diesel List of Capacities Pumps Coolers Exhaust Gas 6...
Page 146: ......
Page 164: ......
Page 165: ...MAN B W MAN Diesel Fuel 7...
Page 166: ......
Page 186: ......
Page 207: ...MAN B W MAN Diesel Lubricating Oil 8...
Page 208: ......
Page 228: ......
Page 229: ...MAN B W MAN Diesel Cylinder Lubrication 9...
Page 230: ......
Page 239: ...MAN B W MAN Diesel Piston Rod Stuf ng Box Drain Oil 10...
Page 240: ......
Page 242: ......
Page 243: ...MAN B W MAN Diesel Central Cooling Water System 11...
Page 244: ......
Page 249: ...MAN B W MAN Diesel Seawater Cooling System 12...
Page 250: ......
Page 262: ......
Page 263: ...MAN B W MAN Diesel Starting and Control Air 13...
Page 264: ......
Page 269: ...MAN B W MAN Diesel Scavenge Air 14...
Page 270: ......
Page 281: ...MAN B W MAN Diesel Exhaust Gas 15...
Page 282: ......
Page 295: ...MAN B W MAN Diesel Engine Control System 16...
Page 296: ......
Page 316: ......
Page 317: ...MAN B W MAN Diesel Vibration Aspects 17...
Page 318: ......
Page 332: ......
Page 333: ...MAN B W MAN Diesel Monitoring Systems and Instrumentation 18...
Page 334: ......
Page 354: ......
Page 360: ......
Page 361: ...MAN B W MAN Diesel Dispatch Pattern Testing Spares and Tools 19...
Page 362: ......
Page 368: ......
Page 380: ......
Page 381: ...MAN B W MAN Diesel Project Support and Documentation 20...
Page 382: ......
Page 391: ...MAN B W MAN Diesel Appendix A...
Page 392: ......