Benefits of NEW-ISO-HV
Revision of IMO requirement
Easy full stroke check lifting
Visible P / V disc operating position
accumulation of vapor & liquid
deck pollution due to spill-over of
liquid & vapor
-Easy replaceable structure
Complies of IMO MSC/Circ. 677
Comply with ISO standard 15364
Meets vapor control system of USCG
Approved by the administrations
Approved by classification societies
The Marine Safety
Committee approved amendments to paragraph 1.2.4 of the Revised standards for
and locating of devices to prevent the passage of flame into cargo tanks in
Devices should be tested and located in accordance with these standards. In
standards, pressure/vacuum valves should comply with ISO standard 15364:2000 "
technology - Pressure/vacuum valves for cargo tanks".
The ISO standard
requires that valves are fitted with a device to indicate its position. And, the
agreed that this does not mean an indicator has to be fitted but that the
position of the
valve should be
visually understood in any way.
disc operating position
high velocity pressure / vacuum valve is designed to prevent the flame passage
into cargo tanks and to relieve excessive over pressure or under vacuum of
during cargo loading, discharging,
and thermal variations.
Also, our valve
could be used to device for gas freeing of cargo tanks and for preventing
penetration of sea water into water ballast tanks during valve and deck are
submerged under seawater level due to vessel's rolling, pitching and stranding
in case of installation on ballast tank.
¢º Optional arrangement 1.
for gas free cover of cargo tank
series high velocity
pressure/vacuum valves could be used with
gas free cover series valve at its outlet top.
So it is
beneficial to cut down extra weight and
of pipe spool for gas free cover.
Optional arrangement 2.
for water ballast tanks
could be installed on water ballast tanks when ballast tank is inserted.
In case of
valve's submerging under the sea water due to rolling, pitching and stranding,
this valve is designed to prevent penetration of sea water into ballast tanks.
Although the NEW-ISO-HV series high velocity valve is submerged under sea water,
sea water is not penetrated into water ballast tank due to closing of pressure
disc and tightness of float on vacuum side.
This arrangement could be reduced ship dead weight and complex piping system
without extension vent pipe near ship center.
Main Factors for Sizing
systems should be designed and operated so as to ensure that neither pressure
vacuum created in
the cargo tanks during or unloading exceeds tank design parameters. The main
factors to be
considered in the sizing of a tank venting system are as follows :
- design loading
and unloading rate ;
during loading : this should be taken account of by multipliying the
rate by a factor of at least 1.25 ;
density of the
cargo vapour mixture ;
in vent piping and across valves and fittings ;
vacuum settings of relief devices.
Reg. 184.108.40.206 (replaced)
arrangements are combined with other tanks, either stop valves or other
shall be provided
to isolate each cargo tank. Where stop valves are fitted, they shall be provided
arrangements which shall be under the control of the responsible ship's officer.
There shall be a
indication of the operational status of the valves or other acceptable means.
isolated, it shall be ensured that relevant isolating valves are opened before
cargo loading or
discharging of those tanks is commenced. Any isolation must continue to permit
caused by thermal
variations in a cargo tank in accordance with paragraph SOLAS Reg. 59. 1.2.1.
Reg. 220.127.116.11 (added)
If cargo loading
and ballasting or discharging of a cargo tank or cargo tank group is intended,
isolated from a
common venting system, that cargo tank or cargo tank group shall be fitted with
over-pressure or under-pressure protection as required in paragraph SOLAS Reg.
Reg. 59.1.11 (added)
before 1 July 1998 shall comply with the requirements of paragraphs 1.2.3 and by
the date of the
first scheduled dry-docking after 1 July 1998, but nor later than 1 July 2001.
MSC/Circ.929 & MEPC/Circ. 362
Safety Committee (MSC) and the Marine Environment Protection Committee (MEPC)
following interpretation for paragraph 8.1.5 of the IBC Code and part E of
BCH Code to cover
the application of cargo-tank venting requirements for combined chemical/oil
chemical tankers ;
provisions for controlled tank venting systems contained in chapter 8 of the IBC
of the BCH Code
should be applied to combined chemical/oil tankers and chemical
tankers in lieu of
the requirements of SOLAS regulation
¥±-2./59.1." Also, the MEPC
adopt the following revised rule requirements of IBC and BCH Code for a
secondary means of allowing
full flow relief of vapor, air or inert gas mixtures to prevent over-pressure or
under-pressure in the event of
failure of a primary means. The following revised rule will be forced from 1
oil/chemical tankers and chemical tankers constructed after 1 July 2002 shall
comply with the above
revised rule. Also, combined oil/chemical tankers and chemical tankers
constructed before 1 July 2002
shall comply with the above revised rule by the date of the first scheduled
dry-docking after 1 July 2002,
but nor later than 1 July 2005."
Examples of acceptable
Amendments to SOLAS introduce new requirements to cargo tank venting systems for
chemical tankers. In substance the new requirements call for double pressure
cargo tanks during loading, discharging and ballasting.
The primary as
well as secondary means for p/v protection may be fitted to each cargo tank or
system or divided, e.g. primary means in a common system and secondary means
to cash cargo tank
Examples of acceptable