Industrial News
What Constitutes the Inspection Scope for Heat Exchangers?

What Constitutes the Inspection Scope for Heat Exchangers?

During various stages of the manufacturing process, inspectors assess the work and document the results of inspections for heat exchangers. The inspection scope for heat exchangers includes: 1. Identification and inspection of raw materials 2. Approval of the welding process completed on the test plate 3. Examination of welders' qualifications 4. Welding groove preparation, involving visual inspection of layering and penetration flaw detection 5. Verification of the quality of welding preparation...

Aug 19, 2021 Industrial News
Why is Water Pressure Testing Necessary After Overhauling the Heat Exchanger?

Why is Water Pressure Testing Necessary After Overhauling the Heat Exchanger?

The purpose of conducting a pressure test after maintenance is to verify the heat exchanger's ability to safely withstand the design pressure, ensuring compressive strength, tightness, interface or joint quality, welding integrity, and sealing structure tightness. Additionally, the test allows for the observation of residual deformation in the base metal weld of the vessel and pipeline to identify any existing material problems promptly. Here is a brief description of the sequence and requirements...

Aug 05, 2021 Industrial News
Establishing the Maintenance Interval for Shell and Tube Heat Exchangers

Establishing the Maintenance Interval for Shell and Tube Heat Exchangers

How to establish the maintenance schedule for shell and tube heat exchangers? In alignment with the "Pressure Vessel Safety Technical Supervision Regulations" and considering the operational conditions of the enterprise, a comprehensive assessment suggests a typical maintenance cycle of 2 to 3 years. What are the maintenance criteria for shell and tube heat exchangers? (1) Extraction of the core, cleaning of the tube bundle, and shell. (2) Execution of welding and expansion procedures...

Jul 05, 2021 Industrial News
Identifying the Causes of Internal Leakage in Tubular Heat Exchangers

Identifying the Causes of Internal Leakage in Tubular Heat Exchangers

Causes of Internal Leakage in Tubular Heat Exchangers: 1. Corrosion, perforation, or breakage of heat exchange tubes. 2. Leakage due to corrosion and thinning of the nozzle. 3. Looseness in the expansion joint between heat exchange tubes and tube sheet. 4. Cracks, blowholes, or corrosion perforations at the welding place between tubes and tube sheet. 5. Loose or broken bolts in the small floating head. 6. Damage to the small floating head gasket. 7. Damage to the seal of the small floating head...

Jun 16, 2021 Industrial News
Repairing Leaky Heat Exchange Tubes

Repairing Leaky Heat Exchange Tubes

What are the situations leading to heat exchanger leakage? Heat exchanger leakage occurs due to cracks and perforations caused by corrosion, wear, scouring, assembly strain, tube defects, or significant wall thickness deviations. How to repair leaking heat exchange tubes? 1. Tube leakage at the nozzle is generally repairable, but internal tube sheet repair is not feasible. 2. If the number of leaking pipes is limited and blocked pipes suffice for production needs, conical metal plugging heads can...

Jun 01, 2021 Industrial News
Identifying the Primary Causes of Plate Heat Exchanger Failures

Identifying the Primary Causes of Plate Heat Exchanger Failures

Under the combined influence of significantly high tube pass pressure and the differential temperature load in the large tube shell pass, the fixed tube sheet heat exchanger fails to meet strength requirements. To address the substantial temperature difference stress, an expansion joint is necessary, but it induces significant stress between the tube and tube sheet under high tube pass pressure, rendering it unable to meet strength conditions. Consequently, alternative heat exchange types, such...

May 17, 2021 Industrial News
Maintaining the Gasket on the Tube Sheet

Maintaining the Gasket on the Tube Sheet

How to Maintain Tube Sheet Gaskets: For optimal performance, ensure horizontal placement to prevent deformation or damage. Reason for Using Same Material on Both Sides of Tube Sheet Gaskets: Uniform pressure distribution is crucial. With identical bolts on both sides, using different materials can lead to uneven pressure, causing sealing failure. Choosing the same material on both sides ensures consistent pressure and prevents sealing issues.  

May 07, 2021 Industrial News
How to Properly Execute Bolt Fastening for Heat Exchangers?

How to Properly Execute Bolt Fastening for Heat Exchangers?

How is the correct bolt fastening sequence for heat exchanger tube boxes and tube plates achieved? Typically, diagonal and cross-bearing methods are used, and torque wrenches tighten the bolts to the specified torque value in the design. Are the material grades of the fastening bolts and nuts for heat exchanger tube boxes and tube plates the same? No, they differ. The material grade of the fastening bolt is higher than that of the nut. The bolt material has higher hardness to avoid damaging the...

Apr 22, 2021 Industrial News
What Causes Intense Vibration in Heat Exchangers?

What Causes Intense Vibration in Heat Exchangers?

Causes of intense heat exchanger vibration: (1) Medium frequency-induced resonance (2) External pipe vibration-induced resonance Addressing severe heat exchanger vibration: (1) Adjusting the flow rate or the natural frequency of the bundle (2) Strengthening the pipe structure to minimize vibration  

Apr 22, 2021 Industrial News