# Oily Water Separator (OWS) - Sampling Line 15 ppm

**URL:** <https://www.queseas.com/t/oily-water-separator-ows-sampling-line-15-ppm/839>\
**Category:** Technical Management\
**Created:** [September 3, 2023, 4:34pm UTC](https://www.queseas.com/t/oily-water-separator-ows-sampling-line-15-ppm/839 "2023-09-03T16:34:57Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Spyros.P](https://avatars.discourse-cdn.com/v4/letter/s/90ced4/32.png) [@Spyros.P](https://www.queseas.com/u/Spyros.P)\
**Post date:** [September 3, 2023, 4:34pm UTC](https://www.queseas.com/t/oily-water-separator-ows-sampling-line-15-ppm/839/1 "2023-09-03T16:34:57Z")

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Dear Queseans,

in the last couple of months, two topics concerning the sampling line of the OWS emerged from PSC inspections which led to some interesting publications from Class societies:

**#Subject 1**  
**The OWS does not stop or does not re-direct the effluent via the 3-way valve from ovb’d to the bilge holding tank, when the sampling line is closed/blocked.**

There were some reports that the above scenario, concerned only some systems manufactured by JOWA, truth is we have seen a similar behavior also with systems from major Japanese vendors equipped with the Bilgemon488 but supplied without a pressure switch in the ppm unit.

_In case the sampling piping is equipped with a valve, it is suggested this valve to be removed or to be sealed in the open position (and same to be written in the oil record book)._

**#Subject 2**  
**The sampling point on the ovb’d line is not located in a vertical section of the piping and/or it is located far from the equipment outlet.**

_This one has to do with the assumption that the sample taken, may not be representative if the sample point is in a horizontal position, as due to the density difference of oil & water, the effluent stream driven to the ppm unit may consists only of water._

For more information please refer to the attached publications from ABS & DNV.  
Remember that for any modifications on the OWS piping, you should have the confirmation from Class first.

[ABS Regulatory News - Letter to Industry OWS Issues and Flow Switch.pdf](https://www.queseas.com/uploads/short-url/1sYLkQ6u5RpfP1yUSKiWydSdP1H.pdf) (440.0 KB)  
[DNV\_TecRegNews\_No\_15\_2023.pdf](https://www.queseas.com/uploads/short-url/uD4VEFQLTt48F2HvwKGznPi0QPb.pdf) (280.1 KB)

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**Author:** ![NikosPiperis](https://avatars.discourse-cdn.com/v4/letter/n/b2d939/32.png) [@NikosPiperis](https://www.queseas.com/u/NikosPiperis)\
**Post date:** [June 19, 2024, 9:47am UTC](https://www.queseas.com/t/oily-water-separator-ows-sampling-line-15-ppm/839/2 "2024-06-19T09:47:34Z")

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Dear @Spyros.P,

To contribute to this topic, a fairly recent marine notice by AMSA focused on the interpretation of Resolution MEPC.107(49) (installations after 2005) and inspection procedures to be followed by PSC officers, can be found attached.  
[Testing and inspection of oil filtering equipment - marine notice 2024-03.pdf](https://www.queseas.com/uploads/short-url/jOcXa6neCCsLAPlMUkV0Vz7Ryvc.pdf) (682.3 KB)