As part of the Equipex Marmor project funded by the ANR, the ENS Paris geology laboratory is in charge of developing an optical pressiometer to be installed on the Mayotte Multidisciplinary Underwater Observatory. To carry out this work, the laboratory platform needs to simulate the temperature and pressure conditions present at the installation site on the seabed. This is possible by the acquisition of a new equipment called hyperbaric enclosure that can go up to 250 bar for a temperature range from 35 ° C to 2 ° C.
The hyperbaric chamber will be used to test the proper functioning of an optical pressiometer that must be installed at a depth of 1720 m. By default, we consider the value of 1800 m. These tests will allow us to prepare and simulate its qualification for the subsea installation, the instrument must finally pass a test program based on class B of the AFNOR NF X10-812 standard.
Either:
1) A step of 8 hours at P = 222 bar, corresponding to 1.2 the maximum working pressure considered PS= 185 Bar and at a temperature of 2 °C.
2) 10 cycles at 185 bar – 1 hour high and low steps, at room temperature.
This hyperbaric chamber must therefore be able to perform these tests.
This hyperbaric chamber will be installed in a pressure room with an area of 17.8 m² where a water supply is present to ensure the water flows necessary for the operation of the pumps for pressurizing the chamber. All equipment will comply in all respects with the European Pressure Vessels Directive: Directive 2014/68/EU and its implementing decree.
The enclosure will have useful internal dimensions with a diameter of 200 mm x 800 mm, it will have a waterproof opening/closing system in the form of a cap, allowing the instrument to be placed inside. It must also be able to accommodate the following watertight passages between the outside and inside of the enclosure: (1) a possible passage for sealed optical fibers according to the characteristics provided by the user (see caracteristique_passage_fibre_optique.pdf, (2) 2 passages for stainless steel tubes external diameter 1/4 inch to ensure the presence of a high-pressure valve outside the enclosure, (3) one passage for single PIN (quantity 10)
This hyperbaric chamber will have to integrate a pumping system to generate pressure inside the chamber, a temperature control system to ensure a stable temperature inside for temperature values ranging from 30 ° C to 2 ° C. There will also be a control system (industrial PC type) to control the pressure and temperature parameters imposed in the enclosure.
An effort should be made to ensure that the various parts, pumps, temperature control system, hyperbaric enclosure are supported as far as possible by a chassis (s) on wheels to facilitate the mobility and maintenance of the different elements.
In order to assess the configuration, technical characteristics and dimensional constraints of the pressure room, during the consultation phase, the candidate has the opportunity to carry out an on-site visit, the modalities of which are specified in the consultation regulations. (see VI.3 additional information in this opinion)
The services are described in CCP n°2023_Enceinte hyperbare_UMR8538,
Variants at the initiative of the candidate are allowed on the following point: type of thermostatic baths for the control of the temperature of the enclosure. The number of variant offers is limited to: 3
Two (2) optional additional services (PSE) are offered:
PSE n°1: Warranty extension of at least one year minimum
PSE n°2: Maintenance contract. The maintenance contract