VAF instruments OILCON MARK 6M - Skid; Sampling Probes

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6.3.5 Skid
The skid is normally located in the pump room and is mounted on the pump room/engine room
bulkhead. The unit should be positioned above the sample pump, but should be kept below the level
of the sampling probe points wherever possible. This is to ensure full pipework and provision of
adequate suction pressure for the pump.
The skid is provided with four mounting points, drilled to accept 12 mm bolts.
A sample point should be fitted between the pump discharge and the skid to facilitate the taking of
grab samples for analysis.
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
 Bulkhead penetration and piping diagram Mark 6M 0806-8038
6.3.6 Sampling probes
WARNING:
IN THE CASE OF AN INSTALLATION AT SEA SAFETY PRECAUTIONS MUST BE
OBSERVED WHILE DRILLING OPERATIONS TAKE PLACE. IN THE CASE WHERE
WELDING IS NOT PERMITTED A SADDLE CLAMP ARRANGEMENT CAN BE
UTILISED. THIS TYPE OF PROBE ARRANGEMENT SHOULD ONLY BE VIEWED AS
TEMPORARY AND ARRANGEMENTS SHOULD BE MADE TO WELD THE PROBE IN
PLACE AT THE NEXT OPPORTUNITY.
Sample point(s) are supplied with the monitor, for location at the selected points on the relevant
overboard discharge lines and contains the following:
 A pneumatic operated valve for selection of the sample point;
 A sample probe to take the sample from the discharge line.
Each probe is supplied with a hand valve and a compression fitting which can be welded to the
pipeline. Positioning of the sample probe within the pipeline is most important. To prevent excessive
quantities of air being drawn into the sample pump, the probe should ideally be mounted in a rising
vertical pipe section. This will ensure that, provide water is being pumped, the main pipe is always
filled. Where it is not possible to mount into a vertical pipe then a horizontal section may be used
and the probe located as shown in drawing 0806-1265. VAF Instruments recommend that whenever
possible the sample probe should be installed on the upstream side of the orifice plate.
In any case the probe should be located upstream of any diverting line to the slop tank.
The important points to note are as follows:
 The probe enters from the bottomside of the pipe.
 The probe is mounted a small distance into the pipe. This ensures a representative sample
and reduces the possibility of picking up “sludge” deposited in the pipe.
 The probe end is located in the lower section of the pipe, partly to increase the possibility of
obtaining an air-free sample and partly to reduce the obstruction in the pipe.
 The sample valve is mounted in the correct orientation. (Air inlet port uppermost)
 The sample valve inlet and outlet ports are correctly mounted.
Reference drawings
 Dimensional drawing sample valve Mark 6 0806-1077
 Part list sampling probe pipe connection Ø15 mm Ballast Monitor Mark 6M 0806-1265
 Schematic installation diagram Oilcon Monitor System with 1x dP/I
transmitter Mark 6 0806-8035