Valves in action -
Back pressure regulator UV 3.9
Tank inertisation on an FPSO
Statistically around 25 % of oil reserves are located in the open sea. Floating production and storage units (FPSOs) are used to extract these reserves at great depths and to store, clean and load the extracted crude oil or natural gas onto tankers. With powerful thruster motors, they can maintain their exact position even in heavy storms.
On the continental shelf off Brazil, an FPSO with 1.4 million barrels of storage capacity is developing an oil field in 2,100 m water depth. Chemical injection systems are used in its production and storage circuit to protect the pipelines and tanks from the corrosive components of the produced crude oil, such as sulfur compounds, and from deposits. Demulsifiers separate the emulsion water from the crude oil, and silicone defoamers are used for the degassing process. Other chemicals are used to clean the process water produced during the extraction of the crude oil and discharge it into the sea.
TASK // Inertisation of chemical storage tanks
The chemical injection module on the FPSO is a multi-level unit consisting of 55 dosing pumps and 25 tanks as well as valves, piping and injection systems. The required chemicals are located in the storage tanks and pumped to the injection point when needed.
In combination with atmospheric oxygen or other substances, the chemicals can form an explosive mixture. To exclude this contact, the empty volume in the head space of the tanks is pressurized with an inert gas, for example nitrogen.
A combination of the DM 762 pressure reducing valve and the UV 3.9 back pressure regulator from Mankenberg captures fluctuating pressures and maintains the pressure of the inert gas in the head space of the tank above the stored chemical.
SOLUTION // Back pressure regulator UV 3.9
The Mankenberg back pressure regulator UV 3.9 is a diaphragm-controlled, spring-loaded proportional regulator for smallest upstream pressures. It controls the upstream pressure constantly without pneumatic or electric control parts. The back pressure regulator opens at an inlet pressure of 40 mbar. This is to discharge 0.4 to 73 Nm³/h of nitrogen when filling the tank system. The outlet pressure is between 0 and 11 mbar.
The valve is made of deep-drawn stainless steel with excellent corrosion resistance. The UV 3.9 is made of deep-drawn stainless steel with excellent corrosion resistance and also available according to ATEX Directive 2014/34/EU and for hydrogen applications.
