PETRO-PLUG Hydrocarbon filter for drainage of pipelines


Hydrocarbons filter stopper, to build-in, medium life

The PETRO-PLUG® is a rainwater filter cartridge contaminated with dielectric oils, fixed vertically in a pipe, for transformers’ retention tanks and pits on small and medium-sized. Its self-locking system traps harmful hydrocarbons, preventing soil pollution. Its oleophilic and hydrophobic polymer component permanently traps hydrocarbons.




The PETRO-PLUG is a cartridge specially invented by SPI® for easy adaptation to all types of retention tanks and pits. It provides continuous filtration of drainage water, while trapping harmful hydrocarbons: it therefore prevents soil pollution in compliance with standard EN 858-1 and the Water Act, with a discharge rate of less than 5ppm. It also complies with paragraph 471 of NF C13-200 (“All precautions must be taken to ensure that the recovery tank does not fill with water or that water is evacuated“). Our filters are regularly tested in independent laboratories, when new, in half-life conditions and after their recommended period of use (see Additional Information tab).


This patented system is ideal for pipes and manholes, and is easy to use, allowing it to be adapted to any pipe for vertical use in the direction of flow.

In the event of a major hydrocarbon spill, the component reacts and forms a plug, preventing any fluid from spilling into the environment. It is a self-locking system, operating without any mechanical parts or electrical connections.


Description of the PETRO PLUG® :

  • Made from rigid PVC with UV protection for extra strength and durability.
  • Hydrophobic, oleophilic polymer component: permanently locks in hydrocarbons.
  • Supplied with a fixing ring, O-ring and a lifting ring for mounting.

For over 30 years, SPI filters have been recognized for their high reliability, extreme robustness and longevity, even under the most difficult conditions: resistance to hot transformer oils (>100°C), water emulsified with dielectric oil, high resistance to ultra-violet rays and thermal amplitudes, etc. SPI has ISO 9001 quality certification for its production process, and has integrated an eco-design approach aimed at reducing the amount of material and CO2 used during the manufacturing process.

Accessories and options

The PETRO-PLUG® range includes several references depending on the use and type of pollutant (hydrocarbons, esters or oil). Contact us for more information.

  • The THPP pre-filter cage is essential to limit the risk of clogging the P-PLUG-PP408 cartridge due to dust in the water. The innovation of the THPP pre-filter, developed by SPI in the 90s, means that only the active cartridge needs to be changed without having to change the whole system: only the filter cartridge needs to be changed.
  • The pre-filter foams can also be refilled on site. Thanks to these two refillable innovations, you can reduce the amount of waste generated by more than 50% for the same maintenance scope.

Technical data

Additional information


Rigid PVC

Conditions of use

indoor, outside


Dielectric oils, Hydrocarbons, mineral oils, natural esters, synthetic esters

Use and maintenance

All industrial equipment or storage units containing hydrocarbons must be fitted with retention tanks.


Before installation:

  • Remove the drain cover and clean the inside of the drain hole to remove any dirt and rust that may be present. The surface must be clean to ensure good watertightness.
  • Make sure that the PETRO PLUG is well adapted to the site configuration. If it is too long, an elevating mounting ring (supplied) may be necessary.



  • Apply a bead of watertight glue to the area in the drain where the mounting ring will be fixed and to the bottom of the mounting ring.
  • Install the PETRO-PLUG® in the drain. The filter must be installed vertically in the direction of flow.
  • A THPP pre-filter for PETRO-PLUG® can be installed (as an option) upstream of the filter to remove impurities from the water and prevent the filter from clogging up too quickly. Alternatively, you can install a pre-filtration disc: place the black felt cloth on top of the PETRO PLUG and fill the drain box with the white silk material.



  • SPI filters are sensitive to sludge and impurities carried by the water, which can considerably reduce the flow rate or even block the filter. Good pre-filtration is therefore essential to protect the filter inlet, and should be checked regularly. The pre-filter should be washed with clean water as often as required by the place of use, the frequency of rinsing depending on the quantity of impurities carried to each drainage point.
  • To keep track of your filters and replacement schedules, SPI products have a batch serial number corresponding to the batch of active ingredient tested and approved by the manufacturer. So you too can track your filters and recommended replacement dates simply by visual inspection.
  • At the end of their life, the filter and pre-filter should be disposed of as conventional hydrocarbon waste under code [150202*].


For your specific needs in terms of traceability and automatic reminders of your maintenance dates, SANERGRID® can set up a unit tracking system for you in return for a maintenance contract with one of our national partners.

Additional information

Part of the SPI® filter technology, the PETRO-PLUG®  range is the European benchmark for small-volume rainwater filter cartridges for hydrocarbon retention. It is the only filter on the market that has been validated for over 30 years by the largest French and European industrial companies (EDF, ENEDIS, SNCF, SCHNEIDER, RTE, ABB HITACHI, SIEMENS, IBERDROLA, NATURGY, REE, EDP, ENEL, IREN, TERNA, E-ON, RWE, VATTENFALL, ELIA, ESB, SCOTTISH POWER, NATIONAL GRID, NETWORK RAIL, UK PN, BRITISH PETROLEUM, TOTAL ENERGIE, BASF, BAYER, ELES, CERN, ITER, VOLVO, DEUTSCHE BAHN, ADIF, SNCB, REPSOL, etc? non-exhaustive list).

Rainwater drainage and hydrocarbon pollution: thanks to the SPI anti hydrocarbons filter system, the tank is empty of water most of the time and ready to receive hydrocarbons. In compliance with water legislation, the water discharged from the tanks is not contaminated with more than 5 ppm of hydrocarbons, in accordance with standard EN 858-1 (“light liquid separation installations”).

SPI® filters PETRO PLUG are regularly tested by independent laboratories: SANERGRID Bureau Veritas report COFRAC I.D. certified: 003606/2776443/1/1/1 in 2015 (France), SPI Phoenix I.D. laboratory reports: AR67044 from 2002, 2004, 2005, 2009, 2018, 2022 (USA), TÜV report Nr 2432974 in 2016 (Germany), NUA report -Z-11895-1/1-2016.


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