10 psig
While leak testing a low-pressure chiller with nitrogen, the maximum pressure should not exceed 10 psig. If it exceeds 10 psig, the rupture disc will burst open.
What is the lowest access point on a low-pressure centrifugal air-conditioning appliance?
The evaporator charging valve is the lowest access point on all centrifugal chillers and air-conditioning appliances.
Where is the rupture disc located on a centrifugal chiller?
25 Cards in this Set
| Where is the rupture disc located on a centrifugal chiller? | Evaporator |
| A hydrostatic tube test kit will; | Determine if a tube leaks. |
How do low-pressure chillers operate?
A chiller works on the principle of vapor compression or vapor absorption. As the heat-transfer takes place, the refrigerant evaporates, changing from a low-pressure liquid into vapor, while the temperature of the process coolant reduces. The refrigerant then flows to a compressor, which performs multiple functions.
When adding nitrogen to a system for leak detection What is the maximum pressure that should be applied to the system?
2. Pressure-dependent leaks:Pressure-dependent leaks are leaks that can only be detected as the system pressure increases. Nitrogen is used to pressurize the low sides of systems to around 150 psig, and high sides to 450 psig. Never use air or pure oxygen.
What is the maximum pressure that should be used for leak testing a refrigeration system with a hermetic compressor?
The low side should not be pressurized above 150 psig and the high side above 450 psig. In the field, the entire system should be limited to 150 psig while looking for leaks.
Which of the following safety precautions should be adhered to for low-pressure systems?
Which of the following safety precautions should be adhered to for low pressure systems? -Do not syphon refrigerant by mouth. -Avoid spilling refrigerant on the skin. -Use gloves and safety goggles when working with liquid refrigerant.
What is the most efficient method for leak checking a charged low-pressure refrigeration unit?
The most efficient method of leak checking a charged low- pressure refrigeration unit is to pressurize the system by the use of controlled hot water or heater blankets. When controlled hot water or heater blankets are not feasible, use nitrogen to increase pressure. When pressurizing a system, do not exceed 10 psig.
How is a nitrogen tank used for pressure testing?
To begin testing a component, a nitrogen tank or on-site nitrogen generator will be connected to the component. Nitrogen will be released to elevate the pressure within the test component to a low pressure while forcing any air, debris, or other substances out of the component.
How is a nitrogen leak test carried out?
A nitrogen leak test follows an orderly set of steps which varies depending on the nature of the equipment to be checked. The process typically requires channeling a steady stream of gaseous nitrogen through the selected pipes, vessels, or vats under increasing amounts of pressure.
How is nitrogen used in the petroleum industry?
While best known is its use in the petroleum industry for pressure testing pipelines and containment vessels, nitrogen is also popular for leak testing in a range of other industries. There are several advantages to using nitrogen for leak detection.
What is the purpose of a leak test?
Leak testing is a method of analyzing industrial storage and transport equipment (vessels, tubing, and pipelines) for defects. Leak testing is done to ensure that newly installed systems can withstand the temperatures and pressures associated with normal operations.
Related
The maximum safe pressure to impose on any low pressure system is: 10 psig.
When leak testing a low-pressure chiller The pressure should not be allowed to exceed 10 psig to avoid?
Question #7: Leak testing a low-pressure refrigeration system with nitrogen in excess of ____ psig could cause the ____ to fail. While leak testing a low-pressure chiller with nitrogen, the maximum pressure should not exceed 10 psig. If it exceeds 10 psig, the rupture disc will burst open.
Where is the lowest access point on a low-pressure centrifugal?
evaporator charging valve
The evaporator charging valve is the lowest access point on all centrifugal chillers and air-conditioning appliances.
What is the most effective way to leak test a charged low-pressure chiller?
The most efficient method of leak checking a charged low-pressure refrigeration unit is to increase the pressure in the system by the use of controlled hot water or heater blankets. If using hot water of heater blankets is not possible, use nitrogen to increase the pressure.
Is 900 microns a good vacuum?
ASHRAE recommends evacuation to below 1000 microns for moisture removal and below 500 microns after replacing a compressor. Some equipment manufacturers call for evacuation to 400 microns to ensure that harmful water vapor is removed from the system.
When leak checking a system, NEVER pressurize the system with oxygen or compressed air. When mixed with refrigerants, oxygen or compressed air can cause an explosion. To determine the safe pressure for leak testing, check the data plate for the low-side test pressure value.
When leak testing a low-pressure centrifugal chiller with nitrogen What is the maximum test pressure?
10 psig
The maximum test pressure using nitrogen on a low-pressure centrifugal chiller is 10 psig. These systems typically use a rupture disc mounted on the evaporator housing to protect the system from over-pressurization.
What is refrigerant added to centrifugal machine?
Type III
| Evaporator charging valve | Refrigerant is added to a centrifugal machine through which valve? |
| Nitrogen | During evacuation of a system with large amounts of moisture it may be necessary to increase pressure with gas such as what to avoid freezing? |
At what pressure does a rupture disc open on a low pressure system?
If a rupture disc type has a burst tolerance of +/-10%, and the defined burst pressure is 1 bar, the rupture disc will open between 900 mbar and 1.1 bar.
Where is the rupture disk on a low-pressure chiller?
25 Cards in this Set
| What is the primary purpose of a purge unit on a low-pressure chiller? | Remove non-condensables from the system. |
| Where is the rupture disc located on a centrifugal chiller? | Evaporator |
Where do leaks commonly occur in low-pressure systems?
On this side of the system, the refrigerant is a cold, low-pressure liquid. The refrigerant line on the system’s low side is often known as the suction line because the compressor’s action pulls refrigerant towards it. Leaks on the suction side most commonly occur in the evaporator coil or one of the fittings.
Related
A) to avoid freezing the chiller bundle B) to avoid causing high compressor current draw C) to avoid opening the high pressure cutout and shutting the system down
D) to avoid breaking the rupture disk and losing the refrigerant charge
Answer: D