Preface: The Foundation of Quality
Within the precision manufacturing system of DG Series Horizontal Multistage Centrifugal Pumps, the pressure resistance and sealing performance of critical components are essential to ensuring long-term, stable pump operation.
To ensure absolute reliability under high-pressure operating conditions, we have established a strict pressure sealing test procedure for the suction section. This standardized inspection process is designed to identify and eliminate potential defects and ensure that every pump delivered meets stringent sealing quality requirements.
Stage 1: Tooling Preparation and Pre-Treatment
Surface Preparation and Installation
Before installing the pressure test blind plate, the external threads of the hose connector must be properly prepared. PTFE sealing tape should be evenly wrapped around the threads to ensure reliable sealing of the threaded connection.
Precision Positioning and Tightening
Accurately install the O-ring into the designated groove of the blind plate. Align the blind plate flange face closely with the end face of the suction section.
Use a torque-controlled tool to tighten the bolts and nuts symmetrically and evenly. This ensures balanced load distribution and prevents deformation of the flange face that could result in sealing failure.
Auxiliary Sealing
All remaining threaded holes in the suction section that are not involved in the test must be securely sealed with threaded plugs wrapped in PTFE sealing tape, forming a completely enclosed test chamber.
Stage 2: Pressurization Test and Pressure-Holding Monitoring
Water Filling and Air Removal
Completely fill the suction section chamber with water. Vent the chamber from the highest point to ensure that no residual air remains inside.
Proper air removal prevents trapped air pockets from causing false pressure retention or inaccurate pressure readings.
Connection and Pressurization
Connect the pressure test pump to the hose connector and start the test pump.
The operator must closely monitor the pressure gauge and gradually increase the system pressure to the specified test pressure required for the corresponding suction section model.
Strict Pressure-Holding Test
Once the specified test pressure is reached, maintain the pressure for 10 minutes.
During the entire pressure-holding period, no pressure drop is permitted, and the pressure gauge reading must remain stable.
Stage 3: Leakage Inspection and Acceptance Criteria
Inspection Method
During the pressure-holding period, use a high-intensity flashlight to conduct a comprehensive visual inspection of the suction section, including weld seams, the casting body, and all flange connection surfaces.
Acceptance Criteria
The sole acceptance criterion is:
No visible signs of leakage.
Any water droplets, mist, dampness, or other evidence of leakage, regardless of how minor, shall be considered unacceptable.
Safety Warning
All personnel involved in the test must strictly follow established safety operating procedures throughout the entire testing process to prevent injuries caused by high-pressure water jets.
Conclusion: Closed-Loop Quality Management
Release to the Next Production Stage
Only suction sections that successfully pass the pressure sealing test may proceed to the next assembly process.
Rejection, Repair, and Retesting
Any component that fails the test must be isolated and handled according to the established nonconforming product control procedure.
After repair, the component must undergo the complete pressure sealing test process again.
The component may only be released after it fully complies with all specified sealing requirements.
Through standardized pressure testing, strict leakage inspection, and closed-loop management of nonconforming components, we ensure the sealing reliability and manufacturing quality of every DG Series Horizontal Multistage Centrifugal Pump delivered to our customers.
Post time: Jul-06-2026