Key words Flashcards
Pipe Types and other key words (8)
Pipe: A tubular section or hollow cylinder used to convey liquids or gases, extensively used on ships for various systems.
Schedule Numbers: Numbers denoting the wall thickness of pipes, ranging from 10 (thin) to 160 (thick).
Black Iron Pipe: Steel pipe with a lacquer coating to prevent corrosion during transit.
Galvanized Pipe: Steel pipe coated with zinc to prevent corrosion.
Stainless Steel Pipe: Corrosion-resistant pipe material, used for high-corrosive mediums like seawater.
Cuper-Nickel Pipe: Pipe made of a copper-nickel alloy, resistant to corrosion, used sparingly due to high cost.
Copper Pipe: Used for HVAC and domestic water lines, valued for malleability and ductility.
Plastic Pipe: Lightweight and used for non-critical systems like drains, not fire-rated.
Fittings (7)
Elbows: Fittings used to change the direction of piping, e.g., 90° or 45°.
Couplings: Components that permanently join segments of pipe.
Unions: Components used to join or dismantle pipe segments easily.
Tees and Wyes: Fittings for creating branches or auxiliary connections.
Flanges: Devices used to connect pipes and components with bolted connections, often sealed with gaskets.
Gaskets: Sealing materials placed between flange faces to prevent leaks and withstand system pressure.
Grooved Fitting Joints: Connections involving a groove and rubber gasket for easy assembly.
Valves (11)
Valve: A device for varying the flow of fluid or gas within a piping system.
Globe Valve: Common valve type, regulates flow via a disc and seat mechanism.
Screw Down Screw Lift Valve: A type of globe valve where the spindle lifts the disc off the seat.
Screw Down Non-Return Valve (SDNR): Valve that prevents reverse flow; closes automatically if pressure reverses.
Gate Valve: Allows straight-through flow; not suitable for flow regulation.
Butterfly Valve: Features a rotating disc to control fluid flow, used in cooling and ballast systems.
Ball Valve: Contains a ball-shaped plug with a drilled passageway for fluid flow.
Check Valve (Non-Return Valve): Prevents reverse flow; includes swing check designs for debris tolerance.
Scupper Valve: A specialized check valve used on ship hulls, prevents backflow of water or debris.
Safety Valve: Fully opens to release pressure when a set point is exceeded, protecting pressure vessels.
Relief Valve: Gradually opens to relieve excess pressure, protecting systems from overpressure damage.
Types of pumps, with subtypes and definitions (10)
Positive Displacement Pumps: Operate by mechanically varying the volume of chambers to draw in and discharge fluid.
Reciprocating Pumps: Use a piston/cylinder mechanism to create a vacuum for suction and compress fluid for discharge.
Rotary Pumps: Use rotary motion to displace fluid, including:
Gear Pumps: Utilize intermeshing gears to create suction and discharge.
Rotary Vane Pumps: Use a rotor with extending vanes inside an eccentric casing to move fluid.
Progressive Cavity Pumps: Use a helical screw and flexible stator to form and collapse cavities for fluid movement.
Rotary Screw Pumps: Use rotating screws to transport fluid along their length.
Centrifugal Pumps: Use a rotating impeller to impart kinetic energy to a fluid, increasing its pressure and velocity.
Axial Flow Pumps: Feature a propeller design to move high volumes of water at low pressures.
Water Ejectors: Vacuum pumps that use high-pressure water or steam to suck in and discharge fluids.
Pump operations (5)
Priming: The process of filling the pump and suction line with fluid to enable operation.
Cavitation: Occurs when the pressure at the pump inlet is too low, causing the fluid to vaporize.
Suction Head: The maximum height a pump can lift fluid from the inlet without cavitation.
Discharge Head: The maximum height a pump can discharge fluid.
Total Head: The sum of suction head and discharge head.
Fire Detection Technologies (4)
Photoelectric Smoke Detectors: Devices that detect smoke by sensing light scattering caused by smoke particles.
Ionization Detectors: Devices that detect smoke through the disruption of ionized air currents within a chamber.
Laser Smoke Detectors: Highly sensitive devices using a laser beam to detect smoke.
Thermal Detectors: Sensors that detect fire by measuring ambient temperature or rate of temperature rise.
Flame Detectors: Sensors that detect the presence of flames by measuring ultraviolet (UV) or infrared (IR) radiation.
CO2 Key Terms and Definitions
Diffuser Nozzles: Devices that distribute smothering gas uniformly within a protected space, ensuring even coverage.
Manifold: A structure in the CO2 system that distributes gas from the storage cylinders to the protected areas via pipelines.
Time Delay Cylinder: A component in a smothering gas system that provides a delay before full gas discharge, allowing personnel time to evacuate the space.
Actuating Valves: Valves that release smothering gas from storage cylinders into the distribution system. They can be manually, pneumatically, or electrically operated.
Non-Return Valves: Valves preventing backflow of gas in the system, ensuring proper operation and safety.
Relief Valves: Safety valves designed to release excess pressure in the system, preventing over-pressurization.
Bulk Storage System: A centralized storage system for large quantities of CO2, maintained under pressure and temperature control.
Refrigeration Units: Components in bulk CO2 systems that keep the gas cool, preventing pressure build-up due to temperature changes.
Ventilation Fans: Mechanical fans used to circulate air in spaces; these must be stopped before discharging smothering gas to maintain system effectiveness.
Alarm System: A set of audible and visual alarms that warn personnel of an imminent discharge of smothering gas, ensuring evacuation.
Pressure Switch: A device that detects pressure changes in the CO2 system and triggers alarms or stops equipment as needed.
Distribution Pipes: Piping systems that carry smothering gas from storage cylinders to the protected spaces.
Siphon Tube: A tube inside the CO2 cylinder ensuring liquid discharge, preventing freezing from rapid evaporation of the gas.
Control Stop Valve: A valve that regulates the flow of gas into the protected space, ensuring proper discharge timing.
Fixed fire systems (8)
Fire Main
A fixed water distribution system used to supply water to fight fires aboard a ship.
Sprinkler System
An active fire protection system that delivers water through overhead pipes and sprinkler heads, activated by heat to control or suppress fires.
Control Mode Sprinklers
Sprinkler heads designed to limit the spread of fire by pre-wetting surrounding combustibles without extinguishing the fire outright.
Suppression Mode Sprinklers
Sprinkler heads designed to rapidly reduce fire heat and extinguish flames without requiring manual intervention.
Pip Cap
A sealing component in a sprinkler head, held in place by a heat-sensitive device or fusible link until activation.
Water Mist Systems
Fire suppression systems that use fine water droplets to cool and smother fires by absorbing heat and displacing oxygen.
Foam Suppression Systems
Systems that use foam to smother fires, cool surfaces, and prevent the release of flammable vapors.
Fire Detection System
A network of sensors and alarms designed to identify and alert personnel of fires.
Inert gas Processes and Methods
Inerting:
Introducing inert gas into a tank to reduce oxygen levels and achieve a non-flammable condition.
Gas Freeing:
Replacing the toxic, flammable, or inert gases in a tank with fresh air to increase oxygen content to 21% by volume.
Purging:
Introducing inert gas into a tank to further reduce oxygen or hydrocarbon levels below flammable limits.
Topping Up:
Adding inert gas to maintain tank pressure and prevent air ingress.
Inert gas Components and Devices
Scrubber:
A device that cools and cleans exhaust gas, removing sulfur dioxide, soot, and particulates, typically using seawater.
Deck Water Seal:
A mechanism to prevent backflow of gases from cargo tanks into the inert gas system. It can be wet, semi-dry, or dry type.
Non-Return Valve:
Prevents reverse flow of gases, ensuring unidirectional movement of inert gas into the tanks.
Blowers:
Machines that deliver inert gas to cargo tanks, usually with redundancy for operational flexibility.
Pressure-Vacuum Breakers:
Devices to prevent overpressure or vacuum conditions in the system.
Types of Inert Gas Sources and their production
Exhaust Gas:
Combustion gas, often from boilers or generators, used as the primary inert gas source after cleaning and cooling.
Nitrogen Generators:
Systems that produce high-purity nitrogen, such as Pressure Swing Adsorption (PSA) or Hollow Fiber Membrane systems.
Types of Bilge systems (4)
Bilge Main
Definition: A common pipeline running the length of the vessel, connecting machinery spaces, cargo holds, or similar compartments for water removal.
Direct Bilge
Definition: A pipeline directly connected from the suction manifold of a pump to specific machinery or cargo spaces for water removal.
Emergency Bilge System
Definition: A backup system for removing water from a vessel during emergencies like blackouts, operating independently of the regular bilge system
Bilge Ejection
Definition: This system uses the cooling water pump for the main engine to pump the bilge. Used only as a last resort because running bilge through the engine could cause serious damage.
Ballast systems
Ballast Main
A common pipeline running along the length of a vessel, connected to ballast tanks via branch pipes, for filling or emptying tanks.
Ballast transfer
This system has a line from each tank going to the suction and discharge of the pump, meaning water can be transferred between tanks without having to go overboard first.
