Hydraulic Tank Crack in Roll Forming Machines – Causes, Oil Leakage, Inspection & Repair Guide
Hydraulic Tank Crack
Roll Forming Machine Hydraulic & Pneumatic Failure Guide
A hydraulic tank crack is a structural failure in roll forming machines where the hydraulic oil reservoir develops a fracture or crack in its metal structure, allowing hydraulic oil to leak and potentially introducing contamination into the hydraulic system.
The hydraulic tank, also known as the hydraulic reservoir, is an essential component of the hydraulic system.
The reservoir stores hydraulic oil and supports several important functions in the system.
These functions include:
storing hydraulic oil supply
allowing air bubbles to separate from the oil
dissipating heat generated by the hydraulic system
allowing contaminants to settle out of the oil
maintaining stable oil supply to the hydraulic pump
In roll forming machines, the hydraulic reservoir typically supplies oil to systems that power:
hydraulic cut-off shear systems
punching stations
press cylinders
coil handling equipment
hydraulic motors
pressure control valves
Hydraulic tanks are usually fabricated from welded steel plates and are designed to withstand continuous exposure to hydraulic oil, vibration, and temperature changes.
However, under certain conditions, the metal structure of the tank may develop cracks.
This condition is known as a hydraulic tank crack.
Tank cracking may affect roll forming machines producing:
metal roofing panels
metal wall cladding panels
standing seam roofing systems
structural deck profiles
C and Z purlins
light gauge steel framing components
Typical production symptoms associated with hydraulic tank cracks include:
hydraulic oil leaking from the tank
oil stains around the reservoir
declining hydraulic oil level
visible cracks or weld failures
air entering the hydraulic system
increased hydraulic system noise
If the crack grows larger, the hydraulic tank may lose significant amounts of oil, potentially causing pump cavitation and system failure.
Maintaining structural integrity of the hydraulic reservoir is essential for reliable machine operation.
Causes of Wear or Failure
Hydraulic tank cracks usually occur due to structural fatigue, mechanical stress, or poor welding.
Several factors may contribute to this condition.
Machine Vibration
Continuous vibration may weaken welded joints.
Poor Weld Quality
Weak welds may crack under stress.
Metal Fatigue
Repeated stress cycles may cause material cracking.
Improper Tank Mounting
Uneven mounting may introduce structural stress.
Impact Damage
External impacts may crack the tank.
Thermal Expansion Stress
Temperature changes may create structural stress.
Why It Happened and What Caused It
From a mechanical engineering perspective, hydraulic reservoirs are subjected to multiple stress factors during machine operation.
These stresses include vibration from hydraulic pumps, thermal expansion caused by changes in oil temperature, and mechanical loads from attached components.
Over time, repeated stress cycles may cause metal fatigue in the tank structure.
Metal fatigue occurs when microscopic cracks form within the material due to repeated loading.
If the tank welds were not properly designed or if the weld quality is poor, these cracks may propagate along the weld seam.
Additionally, improper tank mounting may allow structural flexing, which increases stress on the tank walls.
If these cracks are not detected early, they may grow larger and eventually allow hydraulic oil to leak.
Proper tank fabrication and mounting help prevent structural cracking.
How to Inspect the Problem
Inspection Procedure
Diagnosing hydraulic tank cracks requires inspecting the tank structure and monitoring oil levels.
Step 1 – Inspect the Tank Exterior
Look for visible cracks or weld damage.
Step 2 – Check for Oil Leakage
Oil stains around the tank may indicate a crack.
Step 3 – Inspect Weld Seams
Cracks often form along welded joints.
Step 4 – Monitor Hydraulic Oil Levels
Unexplained oil loss may indicate tank leakage.
Step 5 – Inspect Tank Mounting Points
Ensure the reservoir is properly supported.
Step-by-Step Technician Guide – How to Fix
Correcting a hydraulic tank crack requires repairing or replacing the damaged reservoir.
Method 1 – Drain the Hydraulic Tank
Remove all hydraulic oil before repair.
Method 2 – Clean the Crack Area
Remove oil residue before welding.
Method 3 – Weld the Crack
Repair the crack using proper welding procedures.
Method 4 – Reinforce the Tank Structure
Install reinforcement plates if necessary.
Method 5 – Refill and Test the System
Refill hydraulic oil and verify leak-free operation.
Preventative Maintenance Tips
Preventing hydraulic tank cracks requires proper structural support and routine inspection.
Inspect Tank Welds Regularly
Routine inspection helps detect early cracking.
Maintain Proper Tank Mounting
Secure mounting prevents structural stress.
Monitor Hydraulic System Vibration
Reducing vibration protects tank structure.
Avoid Overheating Hydraulic Oil
Thermal expansion may increase structural stress.
Maintain Proper Oil Levels
Stable oil levels reduce pump cavitation risk.
FAQ Section
What causes hydraulic tank cracks in roll forming machines?
Vibration, poor welds, metal fatigue, or impact damage may cause tank cracks.
Can a cracked hydraulic tank cause oil leaks?
Yes. Cracks allow hydraulic oil to escape from the reservoir.
How can tank cracks be detected?
Visible cracks, oil stains, or falling oil levels may indicate a crack.
Can a cracked hydraulic tank be repaired?
Yes. Small cracks may be welded or reinforced.
Can vibration cause hydraulic tank cracking?
Yes. Continuous vibration may weaken weld joints.
How can hydraulic tank cracks be prevented?
Proper tank mounting, vibration control, and routine inspection help prevent this issue.