VAF instruments OILCON MARK 6M, Technical Manual

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12
2.2.6 Sample probe valve assembly
Reference drawings

Dimensional drawing sample valve Mark 6
0806-1077

Part list sampling probe pipe connection Ø15 mm Ballast Monitor Mark 6M
0806-1265

Part list isolating valve Ø15 Ballast Monitor Mark 6
0806-1268
For taking a representative sample of the ballast water to measure the oil level content, a sample
probe valve assembly is provided. It comprises:

a probe, for penetration in the selected discharge line;

a gate valve, for manual closure upon completion of monitoring;

a pneumatic valve, for remote selection of the discharge line, so the line can be changed
whilst the monitor is in operation.
2.3 SAMPLING SYSTEM ARRANGEMENTS
Reference drawings

Dimensional drawing and parts list ballast skid Mark 6M
0806-1288

Schematic installation diagram Oilcon Monitor System with 1x dP/I
transmitter Mark 6
0806-8035
A suggested installation configuration of the Oilcon
®
Oil Discharge Monitoring and Control System is
given in drawing
0806-8035
. Up to 6 sampling points can be catered for, although most ships will
have much less than this. The total number of valves that are contained in the system is depending
on the particular configuration on the ship.
The sample point is selected from the MCU in the ship’s cargo control room (CCR). This causes the
selected valve to open. When the system is in operation, water is drawn from the sample point by
the sample pump, passed through the detector cell and then discharged to the slop tank or
discharged overboard, depending on the installation.
The accuracy of the monitor is improved by the use of a flushing sequence before sampling
commences, at intervals during sampling and when the system is shut down after use. All the
flushing sequences are carried out automatically by the system.
The flushing sequence serves 3 purposes:

to clean the pipework

to keep the detector cell windows clean, which keeps the optical path un-obscured

to perform a zero check every time a flush sequence is activated
The flushing sequences can be operated manually from the MCU, if required.
The skid assembly, see drawing
0806-1288
, contains a pneumatically operated shuttle valve, which
facilitates the forward flush and backward flush. During the automatic flushing sequences on start
up, and on shut down, the valve activates to flush all the pipework using the fresh water supply and
sequentially selects between backward and forward flush. When the manual flush is operated,
valves are activated to allow fresh water into the system and an additional zero check is performed.
During sampling every 3 minutes, an automatic cleaning of the windows in the detector cell is
carried out. A pneumatic pump mounted in the skid assembly supplies high pressure fresh water
which is sprayed across each window. It will be noticed that the window wash sequence is indicated
on the MCU in the top left corner by “window wash”.