Normal range and basis for fire pump outlet pressure gauges
The normal range of a fire pump outlet pressure gauge is typically 0.8-1.4 MPa. This range is based on the following professional standards:
1. National Standard Requirements: According to Article 5.1.6 of the "Technical Specifications for Fire Water Supply and Fire Hydrant Systems" (GB 50974-2014), the fire pump outlet pressure must meet the operating pressure requirements of the fire extinguishing equipment at the system's most unfavorable point. The general design value is 0.8-1.4 MPa.
2. Practical Application Scenarios:
- Low-rise buildings (such as residential buildings and small shopping malls) typically have a lower pressure limit of 0.8 MPa.
- High-rise buildings or large complexes require a pressure range of 1.0-1.4 MPa to overcome pipe resistance and elevation differences.
3. International Reference: The US NFPA 20 standard also recommends maintaining a fire pump pressure of around 1.0 MPa, which is generally consistent with domestic standards.
Possible Causes and Solutions for Abnormal Pressure
If the pressure gauge reading is outside the normal range, analyze the following:
1. Low Pressure (<0.8 MPa):
- Cause: Impeller wear, pipe leaks, insufficient power supply voltage, or clogged suction port.
- Solution: Check for leaks, clean the filter, and replace the impeller or increase pressure if necessary.
2. High Pressure (>1.4 MPa):
- Cause: The outlet valve is not fully open, the pipe is clogged, or the pressure gauge is out of calibration.
- Solution: Check the valve status, clear the pipe, and regularly calibrate the pressure gauge.
How to Properly Monitor and Maintain a Pressure Gauge
1. Regular Calibration: Perform calibration every six months in accordance with the "Pressure Instrument Verification Regulations" (JJG 52-2013) to ensure accurate readings.
2. Daily Inspection: Observe the pointer for stability, check the dial glass for cracks, and check for leaks at the joints.
3. Linkage Test: Combined with a fire protection system trial run, simulate actual operating conditions to verify whether the pressure response meets the design value.
Additional Note: The pressure gauge value is only one indicator of the fire pump's health; it must also be considered in conjunction with other parameters such as flow rate and current. For example, if the pressure is normal but the flow rate is insufficient, a partial blockage in the pipeline may be the cause. It is recommended that users maintain complete fire pump inspection records and retain the inspection report issued by a professional organization for future reference.