How does a marine riser work?
Exhaust manifolds and risers are large metal castings that carry hot exhaust gases away from the engine on inboard engines. At the aft end of the riser, water from the water jacket combines with and cools the hot exhaust gases before continuing out the exhaust overboard discharge.
What is a riser in offshore drilling?
The risers are pipes through which the drill string carries out the drilling function. A marine drilling riser system provides a tubular conduit from the drilling unit to the subsea blow out preventer (BOP) and the wellbore below it. The drilling riser is composed of a series of joints which are connected by couplings.
What is riser system?
1 General. A riser system is essentially conductor pipes connecting floaters on the surface and the wellheads at the seabed. There are essentially two kinds of risers, namely rigid risers and flexible risers. A hybrid riser is the combination of these two.
What is a riser in a rig?
1. n. [Drilling] A large-diameter pipe that connects the subsea BOP stack to a floating surface rig to take mud returns to the surface. Without the riser, the mud would simply spill out of the top of the stack onto the seafloor. The riser might be loosely considered a temporary extension of the wellbore to the surface.
What is a marine exhaust riser?
Marine engine exhaust riser is an important part of any marine engine exhaust system, whether big or small. Attached to the exhaust manifolds of the engine cylinders, exhaust risers act as the connection between the cylinder manifold and exhaust hose.
What are the types of riser?
Types of riser
- Dry riser: Used to supply water within buildings for fire-fighting purposes.
- Wet riser: Used to supply water within buildings for fire-fighting purposes.
- Stairs riser: The vertical face between the back of the tread of one stair and the front of the tread of the stair above.
How does a riser work?
The risers are located inside the tower, spanning the distance from the seafloor to the top of the tower and the buoyancy tanks. The buoyancy of the tanks keeps the risers tensioned in place. Flexible risers are then connected to the vertical risers and ultimately to the facility above.
What is the function of riser?
A riser, also known as a feeder, is a reservoir built into a metal casting mold to prevent cavities due to shrinkage. Most metals are less dense as a liquid than as a solid so castings shrink upon cooling, which can leave a void at the last point to solidify.
Why is it called a dry riser?
The reason it is called a ‘dry’ riser is that there is no water in the pipe; the pipe is filled with compressed air which prevents water entering the pipe unless a fire activates one of the sprinklers. The inlet for the dry riser is visible on the outside of the building at ground level.
Why do marine engines need risers?
All marine inboard engines have exhaust risers. The exhaust riser has two functions: (1) to keep water from backing up into the engine through the exhaust piping and, (2) it serves as the device that introduces cooling water into the exhaust exit piping system.