T-2 Flashcards
Four Measured Variables
- Pressure
- Temperature
- Level
- Flow
Pressure: Low Pressure
Pressure in a process component less than the minimum operating pressure.
Pressure: High Pressure
Pressure in a process component in excess of the maximum operating pressure, but less than the MAWP.
Pressure: MAOP
Pipelines. Highest operating pressure allowable at any point in a pipeline system during normal flow or static conditions.
Pressure: MAWP
The highest operating pressure allowable at any point in any component other than a pipeline during normal operating or static conditions.
Pressure: Overpressure
Pressure in a process component in excess of the maximum allowable working pressure.
Also and Undesirable Event.
Temperature: Low Temp
Temperature in a process component less than the minimum operating temp.
Temperature: High Temp
Temperature in a process component in excess of the design operating temperature.
Temperature: Excess Temp
Temperature in a process in excess of the rated working termperature.
Also Undesirable event.
Level: Low Liquid Level
Liquid Level in a process component below the lowest operating level.
Level: Gas Blow-by
The discharge of gas from a process component through a liquid outlet.
Also and Undesirable Event.
Level: High Liquid Level
Liquid level in a process component above the highest operation level.
Level: Liquid Overflow
The discharge of liquids from a process component through a gas outlet.
Also an Undesirable Event.
Flow: Low Flow
Flow in a process component less than the minimum operating flow rate.
Flow: Backflow
Fluid flow in a process component opposite to the normal flow direction.
8 Undesirable Events
(LOUDLEEG)
- Overpressure
- Under Pressure
- Liquid Overflow
- Gas Blow-by
- Leak
- Excess Temperature
- Direct Ignition Source
- Excessive Combustible Vapors in the Firing Chamber
Emergency Support System
(ESS)
- Containment
- Emergency Shutdown Systems (ESD)
- Fire Loop
- Gas Detection System
- SSSV
Normally Closed Valve
A valve that will shift to the closed position upon loss of power medium
Types of Normally Closed Valves
- Shutdown Valve
- Surface Safety Valve
- Underwater Safety Valve
Normally Open Valve
A valve that will shift open upon loss of power medium.
Types of Normally Open Valves
Blow Down Valve
Down-Hole Valves
Subsurface Safety Valves:
- SCSSV - Controlled from the surface
- SSCSV- Actuated by well pressure
Fired Vessel
A vessel in which the temp. of a fluid is increased by the addition of heat supplied by a flame within the vessel.
Automatically Fired Vessel
Fired vessel with the burner fuel controlled by an automatic temperature or pressure.
Flame Failure
A flame that is inadequate to instantaneously ignite combustible vapors entering the firing chamber.
Excessive Combustible Vapors in the Firing Chamber
When there are Combustible vapors in addition to those required for normal ignition of either the pilot or main burner.
Abnormal Operating Condition
When operating variable ranges outside of its normal operating limits
Detectable Abnormal Condition
An Abnormal Operating Condition that can be automatically detected
Failure/Malfunction Difference
Failure- Prevents Completion of design function
Malfunction- Does not prevent malfunction, but operates improperly
3 Modes of Safety System Operation
- Automatic Monitoring & Automatic Protective Action if Abnormal conditions occurs
- Automatic Protective Action if manually actuated by personnel
- Continous protection by support systems that minimize effects of escaping hyrocarbons (ESS)
Purpose of Production Platform Surface Safety System
Protecting:
- Personnel
- The Environment
- The Facility
Objective of a Production Platform Surface Safety System
Prevent the release of hydrocarbons from the process and minimize the adverse effects when they occur.
Two levels of protection to prevent or minimize the effect of equipment faiure
- Primary
- Secondary
Requirements for two levels of protection
- Independent of and in addition to the control system
- Provided by functionally different types of safety devices for a wider spectrum of coverage.
TSE
Temp. Safety Element. (Fusible Element)
USH
Flame Detector
TSH
Thermal Detector
YSH
Smoke Detector
ASH
Combustible Gas Detector
What must all gas compressors be equipped with?
- PSH, PSL, PSV, LSH, and LSL on the suction scrubber and each interstage scrubber
- TSH on each discharge cylinder
- BDV on discharge line if horsepower > 1000
How long must fuel last for power during platform shutin?
30 MInutes
When can you leave the LSL off of a compressor scrubber?
If there is a choke on the dump line.
How long until the SSV have to be shut after actuation of ESD?
45 seconds
How long until SCSSV must close?
2 minutes after SSV.
5 Requirements for using Boarding Shutdown Valve (BSDV)
- Design Pressure of all components fully rated for Maximum Source Pressure
- BSDV fire rated for 30 minutes
- BSDV is within 10 feet of boarding pipeline riser access
- TSE located within 5 feet of BSDV
- BSDV tested monthly
What setting must the PSH be?
- No higher than 15% or 5 PSI, whichever is greater, above operating pressure
- 5% or 5 PSI, whichever is greater, of the relief valve set pressure
What setting must PSV be?
No higher than MAAWP of the vessel or pipeline
ASH Set point and tolerance
Set points are 25 and 60 percent of LEL. LEL is 5%. Tolerance is 5% of full scale reading.
Flowiine FSV SCSSV, Tubing Plug, Injection Valve Tolerances.
200 cc of liquid per minute, 5 cubic feet of gas per minute.
