Rigid Conduit Manifold (RCM)

The Rigid Conduit Manifold (RCM) is a collection of valves and hydraulic circuits that direct the hydraulic supply from the surface to various subsea control system components and assemblies. The RCM is mounted on the Lower Marine Riser Package (LMRP) and is typically supplied at pressures of 5,000 psi. Hydraulic fluid passes through the Blue and Yellow supply valves, then through a stack mounted regulator which drops the pressure to 3,000 psi for the pod pilot supply.

The RCM consists of a single unit that contains both the Blue and Yellow sections. The Blue and Yellow sections of the RCM provide independent, yet redundant hydraulic circuits for the Blue and Yellow control systems respectively. The unit contains a crossover valve (Main Isolator) that allows hydraulic supply transfer from one section to the other. This allows for the failure of a supply line while maintaining the option of operational control from either control pod.

The hydraulic supply from the rigid conduit is connected to the RCM. During normal operation, 5,000 psi hydraulic fluid from the Rigid Conduit is directed through a trash collector, a filter, and then through a normally open 1 ½ in. SPM valve. This valve (Rigid Conduit Isolator) can be closed and another valve opened (Rigid Conduit Flush valve) in order to vent hydraulic fluid from the Rigid Conduit that may be contaminated with seawater.

The hydraulic supply from each Hotline is connected to the RCM. During normal operation, the 5,000 psi hydraulic fluid from the Hotline is directed through a normally open ½ in. SPM valve. This valve (Hotline Isolator) can be closed in the event of a hotline failure.
Both the Rigid Conduit Supply and the Hotline Supply are checked in to the RCM with check valves, to prevent loss of hydraulic pressure in the event of a hydraulic supply line failure.

The manifold is arranged in two fully redundant circuits (Blue and Yellow) whereby hydraulic supplies may be distributed from either the Blue or Yellow Rigid Conduit to either control pod.

Each control pod pilot circuit is supplied by a normally open SPM valve. Since the supply valves and the Main Crossover valve are also normally closed, this ensures that if any supply line is operational, the pilot circuits of the control pods are supplied with hydraulic power.

The RCM supplies each control pod with its own pod supply isolator valve. These are 1 ½ in. normally closed SPM valves, which are piloted open when the pod select function is activated (i.e. Blue Pod or Yellow Pod).

Key Features

  • Mounted on the Lower Marine Riser Package (LMRP) the Rigid Conduit Manifold (RCM) acts as the main distribution manifold for various subsea control system components and assemblies. The RCM consists of a single unit that contains both the Blue and Yellow sections The Blue and Yellow sections of the RCM provide independent, yet redundant hydraulic circuits for the Blue and Yellow control systems respectively.
  • Oceaneering Rigid Conduit Manifolds can be found on over 30 deepwater rigs throughout the world in many different levels of design configuration, functional architecture and redundancy levels.
  • Industry known and field proven to be the most reliable, robust, redundant and compact designed RCM available on the market today.