Preparations Before Disassembly
System Shutdown and Isolation
Close the inlet and outlet valves of the heat exchanger and cut off the power supply (if electrically driven).
Completely drain the medium (water, steam, oil, etc.) from the pipeline through the drain valve or vent valve.
Cool the system down to room temperature (to avoid scalding or leaks caused by thermal expansion and contraction).
Safety Measures
Obtain equipment maintenance work permits and confirm no residual pressure.
Wear protective equipment: gloves, safety goggles, anti-slip shoes.
Set up warning signs and isolate the work area.
Tool and Spare Parts Preparation
Ratchet wrench set (selected based on bolt specifications, such as M8/M10 square drive heads).
Torque wrench (for precise control of tightness).
Spray bottle (with cleaning agent or lubricant for handling rusted bolts).
Ladder or support frame (for use during high-altitude work).
Spare sealing gaskets and bolts (for replacement if necessary).
II. Disassembly Process
1. Loosen the Fixing Bolts
Symmetrical bolt loosening:
Plate heat exchangers are typically fixed by multiple sets of bolts (e.g., symmetrically arranged at the four corners).
Key operational points:
Loosen the bolts in diagonal order to avoid localized stress concentration and deformation.
In the initial stage, rotate counterclockwise with low torque (pause every 15° rotation with the ratchet wrench).
If bolts are rusted and stuck, spray a small amount of WD-40 or rust remover and let it sit before operating.
2. Remove the Top Plate/Side Plate
Top plate removal:
After all bolts are initially loosened, use a pry bar or puller to gently pry the edge of the top plate and slowly lift it vertically upward.

Protect the sealing strips between the plates to avoid damage from forceful pulling.
Side plate removal:
If the structure is complex (e.g., multi-channel heat exchangers), remove the side plates first, then extract the plates one by one.

3. Extract the Plates
Sequential extraction:
Plates are usually arranged in groups in a "left to right" or "right to left" order.
Use specialized clamps or grip both sides of the plate with both hands and pull it out horizontally parallel to the flow direction.
If plates are stuck, gently tap the edges to vibrate them apart (tilting or bending is prohibited).