Maintenance of heat exchangers

Описание: Here's a more detailed description:
Purpose:

1.Shell & tube type heat exchanger
2.U tube type heat exchanger
3.fixed tube-to-tubesheet heat exchanger
4.floting head bundle
5. heat exchanger maintenance


Leak Detection:

Pneumatic tests help identify leaks in heat exchangers by observing for pressure loss or by using a soap solution to detect leaks at joints and connections.

Integrity Verification:

The test ensures the exchanger can withstand the design pressure and that all welds and joints are sound.

Procedure

1. Preparation:
The heat exchanger is cleaned, dried, and prepared for testing.

2. Pressurization:
The heat exchanger is filled with air or nitrogen to a specified pressure, usually 1.1 times the maximum allowable working pressure (MAWP).

3. Leak Detection:
Pressure is monitored for any loss, and joints are checked for leaks using a soap solution.

4. Duration:
The test pressure is maintained for a minimum time, typically 10-15 minutes.

5. Evaluation:
The exchanger is assessed for any leaks, and the test is considered passed if no leaks are detected.
Safety Considerations:

Compressed Gas Hazards:
Due to the potential for explosive release of compressed gas in case of a failure, safety precautions are essential.
Pressure Relief Devices:

Pressure relief valves or other devices should be installed to prevent overpressure.
Personnel Protection:

Personnel should be kept at a safe distance during the test and be shielded from potential projectiles in case of failure.
When to Use:

Water Not Suitable:
When water cannot be used as the test medium, such as in certain tube-to-tubesheet joints.
Specific Applications:

For applications where rapid pressurization and shorter test durations are needed, or for testing gas systems.

1. Pre inspection - check all the components gasket area tube bundle

2. Post inspection - All components should be clean
Tube bundle should be clean

3. NDT - tube budle - RFET
4. NDT - Shell & Components - MPI & DPT of T- joints
5. Thckness survey of all Shell and components

6. Hydrotest three steps in Floating head Exchanger
1- Shell side hydrotest -Cheak all the tubes if leakage water comes from tube side

2- Tube test -check the shell nozzles if any leakage water comes from shell outlet nozzle

3- Final test - check all the Flanges areas like channel head flanges,channel cover flanges,Dished flanges if leak is there then water comes from the gasket area

4.check the pressure gauge it should be 1.5 time to 4 times of the test pressure two gauges are required for hydrotest inlet and outlet both are same if pressure is 20 then minimum 35 kg to maximum 80 kgcm/2 both gauge are same

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