2. DESPLAZAMIENTO INTERNO POR DESASTRES NATURALES EN EL
2.1 Una mirada a los desastres naturales en el desplazamiento interno a nivel mundial
2.3.1. Amenazas por inundaciones
MLM Vessel Repeater Window
b) Load Histograms
The mooring line loads are displayed graphically as histograms. The histograms are grouped by dolphin and are individually labelled. Histogram Colour Coding
The histograms change colour according to the status of the hook loads. The colour scheme is:
Green Line tension is acceptable.
Red Line tension is beyond High or Low alarm point Grey Shore side MLMS has flagged illegal data.
These loads are also crossed out with red
Navy Old data is indicated, after a loss of two data packets, by navy-blue histograms
Numerical Load Display
The line tension can be viewed numerically on the pedestal. The readout in a pedestal, below the histograms, can be toggled on and off by left-clicking the pedestal with the mouse.
Histograms with numerical load readout on and off c) Mooring Patterns
A graphical representation of the preferred mooring pattern may be created, saved edited, recalled or deleted for each jetty. Dragging a line from a hook to a fairlead position draws a mooring line. Right-clicking on the fairlead allows a choice of which line to remove. Continue drawing or deleting lines for each active hook until the mooring pattern is completed. Once complete the pattern can be saved for this jetty
Creating and Saving a Mooring Pattern
8) Communications Status
Communication between the Shore Data Monitoring System and the Mooring Line monitoring system is via the serial port.
Communication Status
The communications status indicator will change from a Red “Not Connected” to a Green “Connected” when a valid data packet is received from the shore-based system. If the connection to shore is lost the status will return to a red “Not Connected”. Data will be marked as bad (grey) or old (navy) depending on the condition of the last packet received.
4 - 99 Part 4 Cargo System
Illustration 4.13.1a Cargo Tank Relief Valves Specification
No. of sets: 8
Tag No. : CR106, 206, 306, 406,108, 208, 308, 408
Design Type: Pilot Operated
Set pressure: 25 kPa
Closing pressure: 22 kPa
Required capacity: - Nm3/h
Relieving capacity: 27,030 Nm3/h
For manual lifting device connection RC1/2 OFF S ET 20 OFF S ET 20 Exhaust Tube Pilot Valve For Test Connection
RC 1/2 Supply Pipe Set Plate Diaphragm Retainer Nozzle Test Gag Adjust Screw Diaphragm Check Plate
Illustration 4.13.2a IBS & IS Relief Valves Specification
No. of sets: 16
Tag No. IBS Type : CR102, 202, 302, 402, 103, 203, 303, 403
IS Type : CR101201, 301, 401, 104, 204, 304, 404
Type: Pilot Operated
Set pressure: 3 kPa (For IBS), 3.5 kPa (For IS)
Closing pressure: 1.8 kPa (For IBS), 2.1 kPa (For IS)
Required capacity: 228 Nm3/h (For IBS), 228 Nm3/h (For IS)
Relieving capacity: 420 Nm3/h (For IBS), 481 Nm3/h (For IS)
For Test Connection Rc 1/2
Supply Pipe Field Test Valve
Pilot Valve Main Valve Exhaust Tube Vent Tube Offset 20 Test Gag Adjust Screw Check Plate Diaphragm
4 - 100 Part 4 Cargo System
4.13 Relief Systems
General Description
Each cargo tank is fitted with two pressure/vacuum relief valves as required by the IGC code. The IBS and IS are each protected by two pressure relief valves per cargo tank. The valves are manufactured by Fukui Seisakusho Co., Ltd. and are designed specifically to work on marine based LNG systems.
4.13.1 Cargo Tank Relief Valves (See Illustration 4.13.1a)
Specification
Manufacturer: Fukui Seisakusho Co., Ltd.
Design Type: Pilot Operated
Type & Size: PSL-MD13-131-LS1(B), 10”x12”
Number of sets: 8
Number per tank: 2
Setting Value
Set Pressure: 25 kPa
Reseating Press: 22 kPa
Required Capacity: - Nm3/h
Relieving Capacity: 27,030 Nm3/h
Relieving Pressure: 131.3 kPa
Vacuum Relievin: -1.0 kPa
The cargo tank relief valves are fitted at the vapour domes of each tank and vent to their associated vent mast riser. A cargo tank pressure sensing line relays the pressure directly to the pilot operating valve. In this manner, accurate operation at the low pressures prevailing inside the tank is assured.
The cargo relief valves are set up initially by the manufacturers for the requirements on the ship. If overhaul of the valves by ship’s staff is carried out, the valves must be checked and reset to the original settings (See manufacturer’s instructions for details).
It is extremely important that the vent mast is checked on a regular basis and drained of any accumulation of water. This is to ensure that the relief valves operate at their correct settings, which would otherwise be altered if water were to accumulate in the vent mast and flow into the valve assembly.
4.13.2 IBS & IS Relief Valves (See Illustration 4.13.2a)
Specification
Manufacturer: Fukui Seisakusho Co., Ltd.
Design Type: Pilot Operated
Type & Size: PSL-MD13-131-S1(B), 2” X 3”
Number of units: 16
Number per tank: Inter Barrier Space: 8
Insulation Space: 8 Setting Value
Set Pressure: 3 kPa (I.B.S), 3.5 kPa (I.S)
Reseating Press: 1.8 kPa (I.B.S), 2.1 kPa (I.S)
Required Capacity: 220 Nm3/h (I.B.S), 83 Nm3/h (I.S)
Relieving Capacity: 502 Nm3/h (I.B.S), 544 Nm3/h (I.S)
Relieving Pressure: 104.9 kPa (I.B.S)
105.5 kPa (I.S)
Vacuum Relieving: -80 kPa
The IBS and IS are protected by 4 relief valves per cargo tank.
A gas detection line is lead out from below the valves, (one point for the I.B.S and one point for the I.S per cargo tank) to the gas monitoring system, to give a constant indication of the atmosphere inside the I.B.S and I.S.
The I.B.S relief valve vapour outlet is led to a separate vent line, which runs up alongside the associated vent mast. This is to prevent any counter pressure or back flow from the main vent mast should the cargo tank relief valves lift, or from the nitrogen snuffing system.
It is extremely important that the vent line is checked on a regular basis and drained of any accumulation of water. This is to ensure that the relief valves operate at their correct settings, which would otherwise be altered if water were to accumulate in the vent mast and flow into the valve assembly.
The I.S relief valves vent directly to deck, via a downward facing tail pipe. It is not necessary for these to be led to a vent mast as the likelihood of LNG vapour in the insulation space is very remote.
The I.B.S and I.S valves are set up initially by the manufacturer for the requirements on the ship. If overhaul of the valves by ship’s staff is carried out, the valves must be checked and reset to the original settings (See manufacturer’s instructions for details).
4.13.3 Pipe Relief Valves
Each section of the cargo pipe work, except the vapour line that can be isolated by two valves, has an overpressure relief valve fitted. The cargo manifold relief lines, the cargo machinery space relief lines and No.3 & 4 cargo tanks relief lines are led to No.3 & 4 vapour domes. No.1 & 2 cargo tank relief lines are led to No.1 & 2 vapour domes.
Specification
Manufacturer: Fukui Seisakusho Co., Ltd.
Design Type: Conventional
Type & Number of units: REC131-S1(E), 12EA
Type & Number of units : REC131-S1(N), 27EA
Setting Value)
Set Pressure: 1 MPa
Reseating Press: 0.9 MPa
4 - 101 Part 4 Cargo System