Framo Cargo Pumps No. 1000-0121-401 Rev.C 14Oct10/AGAa Operation manual SD100 SD125 SD150 SD200 SD250 SD300 SD350 F
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Framo Cargo Pumps
No. 1000-0121-401 Rev.C 14Oct10/AGAa
Operation manual
SD100 SD125 SD150 SD200 SD250 SD300 SD350
Framo Cargo Pumps OPERATION MANUAL
No. Date/Sign.: Page: Rev. C:
1000-0121-401 08Jun98/AGAa 2 of 20 14Oct10/AGAa
CONTENTS 1 GENERAL DESCRIPTION ....................................................................................................... 2 1.1 Top plate ........................................................................................................................ 2 1.2 Pipe stack ...................................................................................................................... 2 1.3 Pump head .................................................................................................................... 2 2 OPERATING INFORMATION .................................................................................................. 4 2.1 Discharging .................................................................................................................... 4 2.2 Running of pumps in parallel ......................................................................................... 6 2.3 Stripping ........................................................................................................................ 8 2.4 Purging of cofferdam ................................................................................................... 11 2.5 Precautions to be taken when handling special types of cargoes ............................... 14 2.6 Tank cleaning / cleaning of pump ................................................................................ 15 2.7 Precautions if using cargo pumps in sea water ........................................................... 16 2.8 Loading of cargo tank .................................................................................................. 17 3 MAINTENANCE INFORMATION ........................................................................................... 18 4 TROUBLE SHOOTING........................................................................................................... 18
Reference to associated instructions 1000-0109-4: Interchange of pump control valve 1375-0027-4: Service manual for Pump control valve (STC)
1 GENERAL DESCRIPTION The Framo cargo pump is a hydraulically driven single stage centrifugal pump – with parts exposed to cargo in stainless steel as standard material. The pump is installed in the cargo tank with suction inlet at the bottom of the tank.
1.1 Top plate The cargo pump is supported by a deck trunk welded to the deck. All the connections are at the top cover plate, to which the pump control valve STC (Speed Torque Controller) is also mounted. This control valve for remote and local operation of the cargo pump regulates the inlet pressure to the hydraulic motor. Thereby the pump speed can be regulated step less from 0 – to max. speed.
1.2 Pipe stack The pipe stack connects the pump head to the top plate by a cargo pipe and a hydraulic section. In addition the stripping pipe, the check pipe and eventually temp. sensor pocket and vacuum drain pipe are integrated in the pipe stack.
1.3 Pump head The pump head is welded or flanged to the pipe stack/casing and supported by the bottom support. The hydr. motor is located inside the pump head and surrounded by low pressure hydraulic oil. The short shaft, supported by bearings lubricated by hydraulic oil, is connected to a single-stage impeller. The hydraulic section is surrounded by a cofferdam that completely segregates the hydraulic oil from the cargo. Leakages to the cofferdam chamber will be purged through the cofferdam check pipe and collected in the exhaust trap when cofferdam is purged. The seal arrangement consists of a mechanical oil seal, single cofferdam lip seal and a cargo seal. The cargo seal is only exposed to static head from the cargo. The backstop unit installed on the shaft enables the pump to be used as a drop line. Wear rings are fitted between the impeller and the volute casing.
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL
Local control valve
Cargo purging valve
Manometer Pump control valve (STC) Cargo Discharge valve Cofferdam purging connection
Stripping valve Top plate Deck trunk
Exhaust trap
Flexible suspension
Cofferdam check pipe Cargo stripping pipe Hydraulic Pipestack Cargo pipe
Cofferdam pipe Hydraulic pressure pipe Hydraulic return pipe
Cofferdam surrounding hydraulic section
Bearings
Hydraulic motor
Mechanical oil seal Back stop unit Cargo seal set Volute casing Wear rings Impeller
Fig. 1
1000-0121-401 08Jun98/AGAa 3 of 20 14Oct10/AGAa
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL
1000-0121-401 08Jun98/AGAa 4 of 20 14Oct10/AGAa
2 OPERATING INFORMATION This procedure describes the normal operation of the cargo pumps. Certain cargoes require special handling procedures for safe handling. In addition to this operation procedure charters instruction, Material Safety Data sheet and any ATC instructions shall be taken into consideration during cargo operation and handling.
2.1 Discharging To get maximum lifetime of the pumps, operate the pumps within the operation range. 125%
Head H
100% 75%
OPERATION RANGE
50%
100% dp
OPTIMUM OPERATION RANGE
80% dp
60% dp
25% 20% dp
0 0
25%
50%
40% dp
75%
5) Increase hydraulic motor pressure until required discharge pressure or capacity is achieved. 300
Manifold pressure
Discharge pressure
1P
225
125%
100%
Note! Avoid running pumps against closed cargo valve with high discharge pressure for a longer period.
150
Flow Q
Check that the hydraulic system is started and enough hydraulic power is available. Operation of pump from cargo control panel: 1) Local control valve and cargo discharge valve must be in closed position. Cargo discharge valve, CLOSED
0 BAR
ON
Note! Check that the system pressure is about 20 bar above the motor pressure of the highest consumer. 6) End of discharging When the tank is close to empty reduce pumping capacity to avoid loss of suction. Reduced capacity This is indicated by a hunting hydraulic pressure, and should be avoided. Empty the cargo tank at reduced hydraulic motor pressure.
Cargo purging valve CLOSED (Purging hose disconnected)
Local control valve, CLOSED
75
HP service valve, OPEN Only to be closed when carrying out service work on the pump.
1P
300
Stripping valve, CLOSED
225 150
2) Start the pump and let it run with hydraulic motor pressure at approx 50 bar for 1 minute.
3) Increase hydraulic motor pressure until the cargo discharge pressure is above cargo manifold pressure.
Manifold pressure
1P
75
300
0
225
BAR
ON
150 75 0 BAR
ON
Start
Discharge pressure
7) When the cargo tank is empty the hydraulic motor pressure will drop. Reduced capacity Close cargo discharge valve and stop the pump (handle in minimum position). 1P
300 225 150
1P
75
300
0
225
BAR
ON
150 75
8) If the pump is to be restarted, relieve the vacuum in pump cargo pipe as described in chapter 2.3, Stripping (page 9).
0 BAR
4) Open cargo discharge valve.
ON
OPEN
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL
1000-0121-401 08Jun98/AGAa 5 of 20 14Oct10/AGAa
Operation of pump from local control valve: 1) Open local control valve (by turning counter clockwise). Cargo discharge valve must be in closed position. Cargo discharge valve, CLOSED Cargo purging valve CLOSED (Purging hose disconnected)
HP service valve, OPEN
Local control valve, OPENED
Only to be closed when carrying out service work on the pump.
6) Increase hydraulic motor pressure until required discharge pressure or capacity is achieved. 7) End of discharging When the tank is close to empty reduce pumping capacity to avoid loss of suction. This is indicated by a hunting hydraulic pressure, and should be avoided. Empty the cargo tank at reduced hydraulic motor pressure. Reduced capacity
Stripping valve, CLOSED
2) Set the remote control handle in maximum position. (Remote control closed)
200 100
300
0
3) Start the pump by closing the local control valve (turn clockwise) and let it run with hydraulic motor pressure 50 bar for approx. 1 minute.
300
0
bar
400
4) Increase hydraulic motor pressure (turn the local control valve clockwise) until the cargo discharge pressure is above cargo manifold pressure. Manifold pressure
400
8) When the cargo tank is empty the hydraulic motor pressure will drop. Close cargo discharge valve and stop the pump by opening the local control valve (by turning counter clockwise).
200
100
bar
Open local control valve CLOSE
Discharge pressure
9) Reset for remote control operation: Set the remote control handle in minimum position (remote control open) and close the local control valve. 5) Open cargo discharge valve
OPEN
1P 300 225 150 75 0 BAR
ON
10) If the pump is to be restarted, relieve the vacuum in pump cargo pipe as described in chapter 2.3, Stripping (page 9).
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL
1000-0121-401 08Jun98/AGAa 6 of 20 14Oct10/AGAa
2.2 Running of pumps in parallel This is a general description for running pumps in parallel.
5) Open cargo discharge valve. (Ref. fig 31, pos. A-B)
OPEN
1) Local control valve and cargo discharge valve must be in closed position. Cargo discharge valve, CLOSED Cargo purging valve CLOSED (Purging hose disconnected)
HP service valve, OPEN
Local control valve, CLOSED
6) Start offloading and raise the hydraulic motor pressure command to maximum (fig.31, pos C).
Only to be closed when carrying out service work on the pump.
Manifold pressure Discharge pressure
Note! Handle in maximum position.
Stripping valve, CLOSED 1P 300
225 150
2) Start the hydraulic system and set the system pressure to about 100-150 bar. (Depending on piping system, cargo sp.gr., visc. etc.)
75
SYSTEM PRESSURE
100
PRESSURE SET
0
400
bar
3) Start the first pump and let it run with hydraulic motor pressure at approx. 50 bar for 1 minute.
7) Start the second cargo pump against closed cargo discharge valve as described in step 3.
2P 300 225 150 75 0 BAR
ON
Start
1P 300 225 150 75 0 BAR
ON
Start
Manifold pressure
ON
200 300
Also see performance diagram for actual pump.
4) Increase hydraulic motor pressure until the cargo discharge pressure is above cargo manifold pressure. (Ref. fig. 31 pos. A)
0 BAR
8) Check that pump discharge pressure is higher than manifold pressure. If necessary adjust the motor pressure until the cargo discharge pressure is just above cargo manifold pressure and then open cargo discharge valve. Manifold pressure
Discharge pressure
Discharge pressure
Note! Handle in maximum position. 1P
2P
300 300
225
225
150
150 75
75
0 BAR
0 BAR
ON
ON
9) Start offloading and raise the hydraulic motor pressure command to maximum (the handle in maximum position). Verify that the ullage in the tank is increasing.
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL 10) Start the next pumps, one by one, following the same procedure, ref. fig. 31 pos. E-F. Ensure that enough hydraulic power is available for the pumps to be run in parallel.
1000-0121-401 08Jun98/AGAa 7 of 20 14Oct10/AGAa
13) When a cargo tank becomes empty, close the cargo discharge valve and stop the pump (handle in minimum position).
11) Increase the hydraulic system pressure until required discharge pressure or capacity is achieved, ref. fig. 31 pos G-H-I. 12) During parallel pumping with differences in tank ullage and pressure losses in deck piping – it is sometimes required to readjust the hydraulic motor pressure on some of the cargo pumps to adjust individual capacities.
1P 300 225 150 75 0 BAR
ON
Stop
Discharge pressure
Manifold pressure
14) If the pump is to be restarted, relieve the vacuum in pump cargo pipe as described in chapter 2.3, Stripping (page 9). SYSTEM PRESSURE
100
200 300
0
400
bar
4P
3P
2P
1P
300
300
300
300
225
225
225
225
150
150
150
150
75
75
75
0
0
BAR
BAR
ON
75
0 BAR
ON
0 BAR
ON
ON
A) 125%
A-B) Open cargo discharge valve.
100%
Head H
Increase hydraulic motor pressure. Cargo discharge valve closed.
75%
100% dp
C) Increase hydraulic motor pressure.
80% dp
A
50%
B
60% dp
C
Pressure loss discharge system
40% dp
25%
D) Open cargo discharge valve - 2 pumps. E)
Open cargo discharge valve - 3 pumps.
F)
Open cargo discharge valve - 4 pumps.
20% dp
0 0
50%
25%
75%
100%
125%
Flow Q
Typical capacity/head diagram for one cargo pump running
G-I) Increase hydraulic system pressure (4 pumps running).
125%
Pressure loss discharge system
I 100%
H
Head H
75%
G
A 50%
B
C
D
F
E
25%
0 0
25%
50%
75%
100%
Typical capacity/head diagram for four cargo pumps running
Fig. 31
125%
Flow Q
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL
1000-0121-401 08Jun98/AGAa 8 of 20 14Oct10/AGAa
2.3 Stripping
The pump impeller acts as a non-return valve, preventing cargo from returning to tank. If the pump speed (hydraulic motor pressure) is too low, cargo will flow through the impeller back to the tank.
8 Purging medium pressure in cargo pipe (bar g)
Stripping is to remove remaining cargo in pump cargo pipe upon completion of the discharge operation. The stripping is done by running the pump locally at reduced hydraulic motor pressure against closed discharge valve while purging the pump cargo pipe. The remaining cargo is then purged into the deck line through the stripping valve.
Minimum required hydraulic pressure to prevent backflow through impeller
6 4 2 0 60
80 100 Hydr. motor pressure (bar)
Fig. 32
The arrangement of deck piping must be taken into consideration when stripping. Optimal procedure for tank stripping to be based on experience on board. The best stripping result is obtained when stripping against lowest possible backpressure. At increased back pressure cargo flow is reduced, and stripping time is increased. High cargo viscosity will also increase stripping time.
120
Cargo deck line back pressure Cargo purging valve/ connection (B)
Cargo discharge valve (D)
Purging medium supply (A)
Examples: Stripping valve (C)
Purging press. - Static head - Back press. = Available purging pressure
I 7 bar II 7 bar 8
-
2 bar 2 bar
-
0 bar 3 bar
= =
5 bar 2 bar
Pressure (bar)
7
Available purging pressure
6 5 4
Purging medium pressure
Local control valve Static head
Purging medium pressure Pump cargo pipe
Available purging pressure
Back pressure
3 2
Static head
1
Static head Flow
0
Reduced stripping flow at increased back pressure
Stripping flow at min. back pressure
Stripping pipe
Fig. 33 Estimated time to empty the pump cargo pipe (Backpressure 0 bar(g), 1cSt, spgr. 1.0) *
SD100 / SD125 / SD150
2 – 4 min.
SD200 / SD300
4 – 7 min
SD350
8 – 9 min
Fig. 34
* Time will be influenced by pump length, back pressure, piping system, type of suction well, cargo, purging medium pressure etc.
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL
1000-0121-401 08Jun98/AGAa 9 of 20 14Oct10/AGAa
Stripping procedure Preparations Purging of cargo deck line
Relieving vacuum in pump cargo pipe A Purging medium supply
B
D CLOSED
1) When the tank is empty, close cargo discharge valve(D) and stop the pump.
CLOSED
OPEN
Purging medium supply
Relieving deck line pressure A
OPEN
CLOSED
2) Connect purging hose to the purging medium supply (A) and cargo purging valve (B).
CLOSED
4) Close the cargo purging valve (B).
CLOSED
C OPEN/CLOSE
5) Purge the cargo deck line either to terminal line, slop tank or other cargo tank in accordance with ships procedure. Close the manifold valve.
3) Relieve vacuum in pump cargo pipe by opening valves at purging medium supply (valve A and B).
Pump stopped
CLOSED
B CLOSED
6) Relieve the deck line pressure into the tank by open and close stripping valve (C).
Note! Purging medium pressure in the hose must always be higher than the pressure in the cargo pipe.
Stripping CLOSED Purging medium supply
7) Start the pump by using the local control valve, and increase hydraulic pump pressure to 90-120 bar.
A B
CLOSED
CLOSED
C OPEN
Note! Optimum hydraulic pressure depends on cargo specific gravity and viscosity, purging medium pressure, static head etc., and must be based on experience on board.
8) Open stripping valve (C) 9) Open cargo purging valve (B) to start the stripping. 10) Continue stripping until pump cargo pipe is empty, identified by frequent speed variations of pump. Note! Do not run the pump unnecessary during stripping. 11) Close stripping valve (C) and valve at cargo purging connection (B). 12) Stop the cargo pump. 13) If necessary, purge the cargo deck line and repeat the stripping sequence. 14) Close valve (A) and disconnect purging medium hose.
Pump running
Alternatively the pump can be stripped into a slop tank through a dedicated deck line. It is also possible to strip to a cargo deck line at low manifold pressure, however stripping time will increase with increased cargo pressure.
Fig. 35
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL
1000-0121-401 08Jun98/AGAa 10 of 20 14Oct10/AGAa
Water test procedure according to Marpol Annex II Test hose Min. Ø75mm
Ensure that the cargo tank to be tested and its associated piping have been cleaned and that the cargo tank is safe for entry.
Manifold valve
Provide 100kPa (1 atmosphere) back pressure at the cargo tank’s unloading manifold, see fig. 36.
10m
Cargo piping
Fig. 36 Suggested back pressure manifold arrangement
- Fill the cargo tank with water to a depth necessary to carry out normal end of discharge operation. Water test with sea water must be followed by a thoroughly rinse with fresh water to remove chlorides. - Purge and relieve pressure in cargo piping according to “Stripping procedure” step 1 to 6. - Follow the normal stripping procedure. Start timing when cargo purging valve is opened, ref. step 9. Stop timing when stripping valve is closed, ref. step 11. - The time taken to be recorded. - Residues to be collected and measured. Note! Residues in cargo deck line to be measured separately. Log the results Tank no
Residues (liter) In suction well On tank top
Duration (sec) Water residues in tank after water test.
Fig. 37
Framo Cargo Pumps OPERATION MANUAL
No. Date/Sign.: Page: Rev. C:
1000-0121-401 08Jun98/AGAa 11 of 20 14Oct10/AGAa
2.4 Purging of cofferdam This procedure describes purging of submerged cargo pumps with «dry» cofferdam. (For submerged cargo pumps with liquid filled cofferdam, refer to instruction 1000-0102-4.)
CLOSED Vent. line CLOSED CLOSED CLOSED Drain valve
The cargo pump cofferdam is essential for segregation of the pump hydraulic section from the cargo – and for seal monitoring. Purging to be carried out at regular intervals for the purpose of: - Leakage rate detection - Condition monitoring of the shaft seal system - Avoid that leakages are blocking the cofferdam
Flexible hose with snap-on coupling
Cofferdam purging connection Purging medium supply Relief valve Exhaust trap
Purging medium
How to purge the cofferdam CAUTION: Exhaust gas and liquid may be hazardous. Wear safety gear and avoid contact with drain from exhaust trap and venting line.
Preparation: 1) Place a suitable container underneath the exhaust trap to collect the leakage.
Exhaust gas
2) Check that drain valve at bottom of exhaust trap is not blocked.
Container to collect the leakage
3) Drain the purging medium supply line for condensed water. 4) Connect purging hose (max. supply pressure 7 bar).
Purging:
Cofferdam check pipe
5) Start the purging by opening the valve at purging medium supply line. Note! A relief valve is fitted at cofferdam purging connection. This is set at 3-3,5 bar to limit the purging pressure for protection of the pump seals. A small leakage from the relief valve is normal when liquid is purged from cofferdam. The valve will also open if the cofferdam is blocked. 6) Check that exhaust gas is coming out of the exhaust trap vent line (to verify that cofferdam is open). CAUTION! Exhaust gas and liquid – watch out ! 7) Purge cofferdam in several sequences if required. Drain exhaust trap between each sequence. 8) Disconnect purging hose. Fig. 38
9) Close exhaust trap drain valve. 10) Log the amount of leakage, -evaluate the result. Note! For handling special cargoes, ref. chapter 2.5.
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL
1000-0121-401 08Jun98/AGAa 12 of 20 14Oct10/AGAa
Purging intervals, - logging of purging result LOADING 1.
VOYAGE
Shortly before loading.
DISCHARGE
1.
1-2 days after loading.
1.
Shortly before discharging.
2.
If no leakage at step 1, purge every fortnight.
2.
Shortly after discharging.
3.
If leakage is detected at step 1, or at a later stage during the voyage, purge this pump every day.
4.
If pumps are used for cargo circulation during the voyage, the cofferdam must be purged before start and after stop.
Note! Neglecting of purging can result in a blocked cofferdam and lack of leakage control. The purging form should be filled in with the results from every purging operation. Each horizontal line in the form represents one cargo in one tank from loading till discharging. If a ship loads and discharges some tanks more frequently than other, an extra form should be filled in for those tanks.
Tank no.
Type of cargo
Date of purging
RESULT: If no leakage, write OK. If leakage, write amount of leakage in litres and type of leakage. (Example: 1H= 1 litre hydraulic oil, 1C= 1 litre cargo, 1 H/C= 1 litre mixture of hydraulic oil and cargo).
Open cofferdam: Yes= air or liquid coming through No = blocked cofferdam
Note action taken new parts installed etc.
PURGING ROUTINE FOR FRAMO SUBMERGED CARGO PUMPS SHIP NAME:__________________________________
VOYAGE NO.: __________________________________
NOTE:
Elec tronic c opy: [email protected] If paper copy: Frank Mohn Servic es AS Ship owner: Elec tronic/ Paper copy
In "Result" column: H = hydr. oil C = cargo W= water condensate
A
In "Open cofferdam" column: Yes = air or liquid coming through No = Blocked cofferdam
Tank No.
Signed by:
Cargo
Shortly before loading Date
Chief Offic er
Result
Open Date cofferdam
B 1-2 days after loading Result
If no leakage at A go to C. If leakage at A purge this pump every day Open Date Result Open Average coffercofferresult dam dam
Chief Engineer
C
D
Shortly before unloading
Shortly after unloading
Date
Result
Open Date cofferdam
Result
Open cofferdam
For long voyages with "no leakage at A" purge at least every fortnight. State action taken, new parts installed, etc.
Pumpman
Fig. 39 Example of FRAMO purging form
Filled in purging form to be sent to Ship owner and to Framo ([email protected]). (Green copy for the ship, red copy for the Ship owner and white copy for Framo.) Ship’s crew to evaluate the purging results and to take necessary action – however in case the ship’s crew needs advice, contact a Framo Service Station.
Framo Cargo Pumps OPERATION MANUAL
No. Date/Sign.: Page: Rev. C:
1000-0121-401 08Jun98/AGAa 13 of 20 14Oct10/AGAa
Evaluation of the purging result Cargo leakage
Hydraulic oil leakage
A small leakage rate of up to about 0.5 l/day (and higher with light cargoes) during pump operation is normal.
Hydraulic oil in the cofferdam normally indicates shaft seal leakage, but might come from flange face seals in pipe stack/ pump head or damage in the pipe stack/pump head.
Acceptable leakage rate depends on the type of cargo and possible consequences in case of leakage. - Risk for clogging of pump cofferdam Cargoes like naphtha, condensate etc. penetrates the shaft seals more easily than lubricating oils, vegetable oils and other viscous cargoes. It is therefore recommended to carefully monitor the leakage rate over a period of time, preferable with different type of cargoes. For critical cargoes, when the leakage rate is about 2 litres/day or higher, the pump must be purged a couple of times daily and service (pressure test-repair) carried out at first opportunity. Intensify the purging if the leakage rate is exceeding acceptable limits. If this is not sufficient to keep the leakage under control it must, depending on the nature of the cargo, be considered to discharge the tank using the portable pump.
A small leakage rate into the cofferdam up to about 10 ml/h (0.25 l/day) from the mechanical oil seal or lip seal during pump operation is normal. For short periods of time, higher leakage peaks can occur. If the leakage rate is increasing above acceptable level, the pump must be purged a couple of times daily and inspected as soon as possible to find the reason for the leakage. Intensify the purging if the leakage rate is increasing above the acceptable level. If this is not keeping the leakage under control, close the hydraulic service valve. Depending of the nature of the cargo consider to use the portable pump to discharge the cargo.
Blocked cofferdam In general we do not recommend operating the cargo pump with blocked cofferdam. For advice, depending of type of cargo etc., contact a Framo Service Station.
Cargo leakage to cofferdam normally indicates shaft seal leakage. But the leakage might come from flange connections or damage (cracks/pin holes) in pump/pipe stack (ref. chapter 4, Trouble shooting). The development of a cargo leakage can be monitored if purging is done according to instructions. Thereby maintenance work can be planned, and unexpected shut down due to leakage can be avoided.
Note!
Always remember to pressure test the cofferdam with 3 bar to locate the leakage prior to any dismantling of the cargo pump.
Framo Cargo Pumps OPERATION MANUAL
No. Date/Sign.: Page: Rev. C:
1000-0121-401 08Jun98/AGAa 14 of 20 14Oct10/AGAa
2.5 Precautions to be taken when handling special types of cargoes The main rule is to have the cofferdam clean, dry and vented to atmosphere through the exhaust trap vent line, in order to detect leakages easily. However, when handling certain groups of cargoes it may be an advantage to fill the cofferdam with liquid to improve the seal lifetime and to avoid solidifying cargo blocking the cofferdam. Recommended type of liquid to be filled into the cofferdam for some groups of cargoes is given below. This is a general advice, only experience can define which liquid gives the best result for the great number of different types of cargoes. Acid cargoes After discharging and purging is finished, it may be an advantage to circulate fresh water through the cofferdam to remove all residues after a leakage.
Phenol, caustic soda etc. A circulation of hot water through the cofferdam can avoid clogging. Note! Remember that some of these types of cargoes are very hazardous.
Polymerising cargoes. (TDI, MDI) Fill cofferdam with dioctyl phthalate(DOP) to limit the risk of blocking the cofferdam.
Heated oil products (fuel oil, crude oil) Fill cofferdam with diesel oil/white spirit to keep any leakage into cofferdam in liquid form. (This is especially important after stripping and during tank cleaning.)
Crystallizing cargoes (molasses, etc.) Fill cofferdam with fresh water. The cofferdam may also be arranged with a small water circulation. CLOSED
Filling
Vent. line
To fill liquid in the cofferdam, disconnect the exhaust trap piping from the pump top plate. Using a suitable adapter, fill the liquid through the cofferdam check pipe. Open the purging connection to ventilate the cofferdam during filling. (Connect an open female coupling or similar).
CLOSED
CLOSED
Open purging connection
Fig. 40
A circulation of liquid through the cofferdam can be arranged in the following way: - Connect liquid supply to the purging connection. The supply line must also be equipped with a valve to regulate the liquid flow. - Open drain valve on the exhaust trap, and collect the return liquid here.
CLOSED
OPEN CLOSED
CLOSED
Liquid return
Liquid supply
Flexible hose with snap-on coupling
Circulation
Valve for regulation of flow
Fig. 41
Note! When filling or circulating liquid in the cofferdam, it is important that the hydraulic oil return pressure always is higher than the pressure in the cofferdam. This is especially important on hydraulic systems with non-pressurised return line.
Solidifying cargoes (in cargo tanks with heating coils) To prevent the cargo to get solid (freeze) inside the suction well, circulate the cargo at intervals by starting the cargo pump.
No. Date/Sign.: Page: Rev. C:
Framo Cargo Pumps OPERATION MANUAL
1000-0121-401 08Jun98/AGAa 15 of 20 14Oct10/AGAa
2.6 Tank cleaning / cleaning of pump For viscous/solidifying cargoes During tank cleaning the pump should be run at approximately the same flow rate as cleaning water / liquid supply. Halfway the tank cleaning time close the cargo discharge valve, open the stripping valve and operate pump for a short period in order to get a good cleaning of wear rings, seal rings, pumps parts and stripping pipe. Then open the cargo discharge valve and run the pump to complete the tank cleaning operation. Cleaning water left in pump's cargo pipe is to be stripped as described in chapter 2.3.
Note! Remains of cleaning water in suction well to be removed to avoid galvanic corrosion.
Suction well empty
Galvanic cell
For corrosive cargoes Tanks to be cleaned should be filled with a large amount of cleaning water to dilute the corrosive cargo. After tank flushing the same cleaning procedure as for viscous / solidifying cargoes should be followed.
Fig. 42
Note! If steam is used to clean the pump, the steaming out period must not exceed 10 minutes, to avoid damage of seals or hydraulic motor. Always purge the cofferdam before tank washing with steam. Note! If using sea water or brackish water for tank cleaning, see chapter 2.7.
Framo Cargo Pumps OPERATION MANUAL
No. Date/Sign.: Page: Rev. C:
1000-0121-401 08Jun98/AGAa 16 of 20 14Oct10/AGAa
2.7 Precautions if using cargo pumps in sea water Seawater tank cleaning (Continuous circulation) Seawater temp. oC
The nominal corrosion rate for stainless steel in sea water is low. However, under certain circumstances, local corrosive attack can take place and the corrosion rate might be severe. High chloride concentrations and low pH increase the probability of pitting and crevice corrosion as do high temperatures and stagnant solutions. Tank cleaning using sea water must therefore be carried out according to qualified procedure.
Tank cleaning
80 70 60 50 40
2 Max. exposure time, hours
4
Fig. 43
- In general the tank cleaning should be carried out within limited time frame at temperature below 60C. Higher temperature up to 80C can be used for a shorter period. (Fig. 43, for guidance only.) - Avoid pH values below 6,5. Check carefully if the ship has been carrying acids. - If hot seawater is used, cool immediately with cold seawater until surface temp. is below 40C before fresh water rinse. This to avoid concentration of chlorides from evaporation on hot steel surfaces. - Tank cleaning with seawater must be followed by a thoroughly rinse with fresh water to remove chlorides.
Seawater temp. oC
Sea water for heavy ballast 40
- When possible, take clean seawater in open sea and avoid contaminated harbour water.
Ballast
30
- Empty the tanks as soon as possible when the ballast is no longer required or when the testing is finished.
20 10
2
4 6 8 10 Max. exposure time, days
Fig. 44
12
- Carefully clean the tank and the pump to ensure no chlorides remain on surfaces.
Framo Cargo Pumps OPERATION MANUAL
No. Date/Sign.: Page: Rev. C:
1000-0121-401 08Jun98/AGAa 17 of 20 14Oct10/AGAa
2.8 Loading of cargo tank In general it is recommended to start the loading slowly to avoid pressure surges in the cargo pipe line and the pump. Correct operation of valves is important. Open / close valves slowly ! If a separate drop line is installed, it is recommended to load through the drop line only.
Cargo discharge valve CLOSED Cargo line Loading pressure Max. 8 bar
OPEN valve Drop line
If required to load through the pump, use following procedure: Note! For sampling procedures, ref. charterer's requirements. - Keep manifold valve closed until the cargo reach the manifold. - Open manifold valve partly to fill cargo line on deck. - Open cargo pump discharge valve and drop line valve slowly. - Open manifold valve slowly until required pressure/capacity is reached.
Fig. 45 Arrangement with separate drop line
Note! Maximum acceptable loading pressure when loading through the pump is 8 bar at the pump top plate.
Framo Cargo Pumps OPERATION MANUAL
No. Date/Sign.: Page: Rev. C:
1000-0121-401 08Jun98/AGAa 18 of 20 14Oct10/AGAa
3 MAINTENANCE INFORMATION Prior to entering a cargo tank for doing service it is essential to become familiar with the ship's safety rules and requirements regarding cargo-handling equipment. Do not enter a cargo tank before the tank is confirmed gas free and safe. Before doing service on pump, always close and lock the hydraulic pressure inlet valve and purge the cofferdam. Purge cofferdam according to chapt.2.4.
Caution: Venting gas and liquid may be hazardous. To prevent skidding and minimize the risk of fire it is important to remove oil spill during maintenance and servicing work. The operator should be confident that all flange connections are in satisfactory condition so as to prevent hydraulic oil and cargo spills.
Close the cargo discharge valve. Ensure that the valve is in closed position until the work/service is finished (info sign to be placed at the control panel/computer).
4 TROUBLE SHOOTING Warning: To prevent damage from hazardous cargoes, take necessary precautions, wear safety gear and avoid contact with spray/gases. Symptom:
Possible reason:
Remedy: *)
COP operational problem (First it is necessary to verify if the problem is in the pump control system or in the pump unit itself).
General
Ref. system service manual - Trouble shooting section
The pump will not start
a) Cargo pump remote control system failure
a) Ref. instruction for Pump remote control
b) Pump control valve failure
b) Ref. Instruction for Pump control valve (STC)
c) Pump impeller stuck.
Pump is vibrating heavily
Too low pumping capacity
c1)Frozen /solidified cargo
c1) Heat the cargo in the pump suction well.
c2)Foreign objects stuck in pump or other mechanical problem
c2) Pump unit to be inspected.
a) Control system problem
a) Ref. instr. for Pump control system.
b) Rotating parts out of balance.
b) Impurities stuck in impeller or other mechanical problem.
a) Control system problem
a) Ref. instr. for Pump control system and instr. for Pump control valve. (If required interchange pump control valve as described in instr. 1000-0109-4)
b) Worn wear rings. Impurities stuck in impeller, or other mechanical problem
b) Pump unit to be inspected
*) Ref. instruction for maintenance and repair for actual pump.
Framo Cargo Pumps OPERATION MANUAL
Symptom:
Possible reason:
No. Date/Sign.: Page: Rev. C:
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Remedy: *) Check hydraulic motor inlet pressure – pressure above 15-20 bar indicates malfunctioning back stop unit.
Noise(non return valve) and vibration when loading through the pump. Damaged back stop unit
Change back stop unit. Contact a Framo Service Station.
Not possible to purge the cofferdam (no air, inert gas or liquid coming out of the check pipe when purging) (See also chapter 2.4)
a) No or insufficient purging medium supply b) Blocked cofferdam system
Note! In case steam is used in attempt to clear a blockage in pump cofferdam system pay special attention not to over pressurize the pump/pipe stack
a) Check valves, hose connections and purging medium relief valve (open at approx. 3 bar). b) Check the exhaust trap and the piping on deck for blockage. Open if possible.
b1) Disconnect check pipe from pump unit (lower seal house) – watch out for possible pressurized liquid in cofferdam!! By carefully purging check if the blockage is located in the check pipe or in the pump/ pipe stack cofferdam. Depending on the nature of the medium blocking the cofferdam system use steam or solvent to dissolve the blockage. Dismantling of pump might be required.
Note! Pressure test pump after assembly. Cargo leakage to pump cofferdam. (See also chapter 2.4)
General Note! Always pressure test pump prior to and after dismantling. This is required to locate possible leakage and to confirm no leakage upon completion of repair.
Pressure test pump cofferdam system at approx. 3 bar. Check for leakage – if required spray with soapy water to locate the leakage.
a) Worn cargo seal a) Replace cargo seal set. Note; If no leakage is Also, carefully check ceramic sleeve for detected by pressure test possible damage-wear. it is likely that the cargo leakage to cofferdam is caused by worn cargo seal. (the upper seal lip is sealing when pressurizing cofferdam). b) Leaking seal element in flange connection
b) Check for loose bolts and for pitting corrosion in seal faces – in case of corrosion repair is required. When assemble, renew damaged seal element.
c) Crack/pinhole in piping c) Contact a Framo Service Station. *) Ref. instruction for maintenance and repair for actual pump.
Framo Cargo Pumps OPERATION MANUAL
Symptom: Hydraulic oil leakage to pump cofferdam.
Possible reason:
No. Date/Sign.: Page: Rev. C:
1000-0121-401 08Jun98/AGAa 20 of 20 14Oct10/AGAa
Remedy: *)
General
Drain the pump return side prior to dismantling. Disconnect pump head/unit from pipe stack/casing. Pressurize pump unit return side at approx 4 bar and check for leakage to cofferdam side. Pressure test pump pipe stack / casing at max 7 bar on cofferdam side and check for leakage to return side.
a) Leaking shaft seal
a)Replace shaft seal (replaced seal to be reconditioned if feasible)
b) Leaking seal element in flange connection.
b) Check sealing surface for possible damage – repair if damaged. When assemble, renew damaged seal element.
(See also chapter 2.4)
c)Crack/pinhole in piping c) Contact a Framo Service Station. *) Ref. instruction for maintenance and repair for actual pump.
Note! Evaluate if changed parts as sleeves, mechanical seals etc. are possible to recondition. Send these parts to a Framo Service Station and ask for an evaluation.