TYPE 2325 GFB GAS FREEING COVER - Pres-Vac Engineering Aps

INSTRUCTION MANUAL FOR
TYPE 2325
SYSTEM DESCRIPTION
AND OPERATING/MAINTENANCE
INSTRUCTIONS FOR
GFB
GAS FREEING COVER
REV. 1
CUSTOMER INFORMATION
OWNER: HULL NO.: PRES-VAC REF. NO.:
PRES-VAC ENGINEERING A/S PHONE: +45 4817 4055
SVANEVANG 3-5 TELEFAX: +45 4817 1788
DK-3450 ALLERØD E-mail: presvac@pres-vac.com
DENMARK

INSTRUCTION MANUAL
CONTENTS
GAS FREEING COVER
TYPE 2325
Page 2 of 6
Rev. 1 December 10, 2009
Page
1. Functional System Description ....................................................................................... 3
1.1. General ................................................................................................................... 3
1.2. Function .................................................................................................................. 3
1.3. Capacity .................................................................................................................. 3
2. Operating Instructions ................................................................................................... 3
2.1. Installation .............................................................................................................. 3
2.2. Operation ................................................................................................................ 3
3. Maintenance Instructions ............................................................................................... 4
3.1. General ................................................................................................................... 4
3.2 Safety Regulations for Maintenance Work .................................................................... 4
3.3 Directions for Disassembly / Assembly and Cleaning ..................................................... 4
4. Spares ............................................................................................................................ 5
DRAWING NO. 2325 .............................................................................................................. 6
5. Laboratory Report, Summary ......................................................................................... 7

INSTRUCTION MANUAL
GAS FREEING COVER
TYPE 2325
1. Functional System Description
1.1. General
Page 3 of 6
Rev. 1 December 10, 2009
The purpose of the gas-freeing cover is to prevent the passage of flames into the cargo tanks during the
gas-freeing procedure.
1.2. Function
Under normal conditions there is free venting throughout the gas-freeing cover. If an ignition occurs
outside the tank space, the flames will be quenched in the flame trap.
1.3. Capacity
The gas-freeing covers capacity is rated in standard air. For convention to maximum loading rates for
different cargoes, please refer to the MASTER’S LOADING CHART as per latest revision of IMO MSC/Circ.
731.
2. Operating Instructions
2.1. Installation
Remove all packing material
Installation is accomplished by bolting the gas-freeing cover flange to the vent pipe mating flange with
suitable gasket between.
As per SOLAS 1974, Reg 59 + 62, the cover shall be located 2 m above the cargo deck level, and the
discharge from the open cover shall be vertically upwards having an exit velocity of at least 20 m/sec.
2.2. Operation
During gas-freeing the cover is open. When the hydrocarbon vapour concentration in the tank is reduced
to less than 2% by volume, venting may also be at the cargo deck level. After gas-freeing, the cover is
closed and the wing nut tightened. Ref. SOLAS 1974 Regulation II-2/59.2.1.
CAUTION! If the gas-freeing cover has been exposed for an explosion, the cover must be
inspected for any damage.

INSTRUCTION MANUAL
3. Maintenance Instructions
GAS FREEING COVER
TYPE 2325
Page 4 of 6
Rev. 1 December 10, 2009
3.1. General
As per SOLAS-requirements, the following service intervals shall be followed as a minimum:
After 6 month of operation, the cover shall be inspected for proper function and, if necessary, be cleaned.
However, we recommend that the cover be inspected more often depending on the cargo type.
After further 6 months of operation, the cover shall be taken apart and cleaned.
NOTE! The need for inspection and cleaning may increase depending on operation conditions,
the loading frequency and the type of cargo.
3.2. Safety Regulations for Maintenance Work
The maintenance work can be carried out when the cover is mounted on the piping system or when the
cover is removed and blind flanges mounted on the corresponding flange joints. In both cases, the cargo
tank should be gas-freed and depressurised before maintenance work is commenced.
Spark free tools should be used if maintenance work is carried out while the cover is mounted on the
cargo tank.
WARNING! All maintenance work must be carried out with necessary precautions in regard to the
cargo’s flammability and toxicity.
3.3. Directions for Disassembly / Assembly and Cleaning
The following procedures refer to drawing no 2325.
1. Open the cover
2. Remove the retaining ring (item 6)
3. Pull out the filter elements (item 5)
Inspection and cleaning
4. The filter elements as well as the rim of the cover must be free from damages, and dust or deposit
must be removed. Do not clean the filter elements using tools - only a solvent should be used.
5. In case of damages filter elements or gaskets, the damaged parts shall be replaced by genuine
PRES-VAC spare parts
NOTE! For cleaning we recommend thin lubrication oil and a brush. If any damage on any
parts is observed, repair or replacement must take place.
Assembly after cleaning and inspection
6. Assembly is done in the opposite sequence.
General
Screws and bolts not protected from loosening should be secured by a suitable adhesive, such as PRES-
VAC part no.: 1323-8.

INSTRUCTION MANUAL
GAS FREEING COVER
TYPE 2325
Page 5 of 6
Rev. 1 December 10, 2009
4. Spares
There are no class requirements for carrying spares on board. If spares are required, please use the
following procedure:
1. Identify the components on the inserted drawing no. 2325
2. Advise builder of ship and new building number.
3. Advise Vessel name.
4. Advise serial number of the cover
When we have the above information, our files contain all further details.
When ordering spare parts, please call our office in DENMARK.
Our telefax and e-mail are open 24 hours a day
Telefax no. ....... +45 48 17 17 88
E-mail .............. presvac@pres-vac.com
Our telephone is open during normal office hours
Telephone no.: . +45 48 17 40 55
Our postal address:
PRES-VAC ENGINEERING ApS
Svanevang 3-5
DK-3450 Allerød
Denmark

INSTRUCTION MANUAL
GAS FREEING COVER
TYPE 2325
DRAWING NO.: 2325 – GAS-FREEING COVER Type GFB
Page 6 of 6
Rev. 1 December 10, 2009