How to Commission and Test a Wates Pressure Vessel After Installation

Correct commissioning and testing are the final and most critical steps after installing a Wates pressure vessel.
Even a perfectly installed vessel can fail to perform if commissioning is skipped or done incorrectly.
Proper testing ensures:

• Stable system pressure
• Correct pump operation
• Reduced cycling and energy consumption
• Long service life of the vessel and pump

2. When Commissioning Should Be Done
Commissioning must be carried out:

• After mechanical installation is complete
• Before the system is handed over to the client
• After any bladder replacement or major maintenance
• After pressure switch or VFD settings are changed

Never commission a pressure vessel while the system is partially installed or under construction.

3. Pre-Commissioning Safety Checks
Before pressurizing the system, verify the following:

• Vessel is securely mounted (no load on pipework)
• Correct orientation (vertical or horizontal as per model)
• Isolation valve, drain valve, and pressure gauge installed
• All fittings tightened and sealed correctly
• Vessel pressure rating matches system maximum pressure
• Installation area is safe, ventilated, and accessible

4. Step-by-Step Commissioning Procedure
Step 1: Isolate and Fully Drain the Vessel

• Close the isolation valve between vessel and system
• Open the drain valve to remove all water from the vessel
• Ensure zero water pressure inside the tank

This step is essential—pre-charge must never be checked with water inside the vessel.

Step 2: Check and Set Pre-Charge Pressure

• Use a reliable air pressure gauge on the Schrader valve
• Compare reading with required value

Correct rule:
Pre-charge = Pump cut-in pressure − 0.2 to 0.5 bar
Example:

• Pump cut-in: 2.5 bar
• Vessel pre-charge: 2.0–2.3 bar

Adjust using an air pump or release air as required.
Re-fit the valve cap tightly (preferably metal).

Step 3: Open Isolation Valve and Refill System

• Slowly open the isolation valve
• Allow water to enter the vessel
• Observe pressure gauge for smooth pressure rise

Check all joints and fittings for leaks.

Step 4: Start the Pump and Observe Cut-Out Pressure

• Start the pump and allow system to reach cut-out pressure
• Confirm cut-out pressure is below vessel maximum rating
• Ensure pump stops cleanly without pressure overshoot

Step 5: Test Drawdown Performance

• Open a tap or outlet downstream
• Observe pressure drop on gauge
• Confirm water flows from the vessel before pump restarts

This confirms the vessel is storing usable water volume correctly.

Step 6: Verify Pump Cycling Frequency

• Run system under normal demand conditions
• Confirm pump does not short-cycle
• Typical acceptable range: 10–20 starts per hour

Excessive cycling indicates incorrect pre-charge or undersized vessel.

5. System Stability Tests
5.1 Pressure Stability

• Pressure should drop gradually, not suddenly
• No pressure hunting or oscillation

5.2 Noise and Vibration

• No banging, knocking, or water hammer
• Vessel should remain stable without movement

5.3 Multi-Pump or VFD Systems

• Pumps should sequence smoothly
• No rapid on/off switching
• Pressure sensor readings should remain steady

6. Final Inspection Checklist
Before handover, confirm:

• Pre-charge pressure recorded
• No air or water leaks
• Isolation valve operational
• Drain valve accessible
• Pressure gauge readable and accurate
• Vessel fully supported and aligned
• System pressure within design limits

7. Common Commissioning Mistakes to Avoid

• Checking pre-charge with water inside the vessel
• Skipping drawdown test
• Ignoring pump cycling frequency
• Leaving isolation valve partially closed
• Failing to tighten Schrader valve cap
• Not documenting final pressure settings

8. Documentation and Handover
Record the following for future maintenance:

• Vessel model and capacity
• Pre-charge pressure value
• Pump cut-in and cut-out settings
• Commissioning date
• Installer or technician name

This documentation is essential for warranty and service history.

9. UAE / GCC Commissioning Notes

• High ambient temperature may slightly increase pressure after commissioning
• Re-check pre-charge after 24–48 hours of operation
• In hot pump rooms, schedule pre-charge inspection every 3–6 months
• Coastal installations require periodic inspection for corrosion

Commissioning and testing are not optional steps—they determine how well a Wates pressure vessel will perform throughout its service life.
Correct pre-charge adjustment, drawdown testing, and pump cycling verification ensure:

• Stable pressure
• Reduced energy consumption
• Longer pump and vessel lifespan
• Fewer service calls

A properly commissioned vessel is the foundation of a reliable water pressure system. For more info contact Wates Pressure Vessel Supplier in UAE or call us at +971 4 2522966.

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