The core principle of stainless steel differential pressure gauges is based on the differential deformation of double elastic elements (such as bellows or Bourdon tubes), which amplify and indicate the pressure difference through mechanical transmission mechanisms. However, different structures have differences in detail design and applicable scenarios. The specific analysis is as follows:
Principle difference: Double corrugated tube vs. Double corrugated tube structure
Double corrugated pipe structure
Principle: Two corrugated pipes are symmetrically installed on both sides of the "I-shaped" bracket, and the high and low pressure ends are connected to the corrugated pipes through conduits. When the pressure at both ends is unequal, the corrugated tube produces displacement, which drives the gear transmission mechanism to amplify the deflection, and the pointer indicates the differential pressure value.
Features: The material of the corrugated tube is usually 316L stainless steel, which has strong corrosion resistance; The spring plate connection design ensures high zero stability and is suitable for measuring small differential pressures (such as filter pressure loss monitoring).
Double Bourdon tube structure
Principle: Two Bourdon tubes (C-shaped spring tubes) are installed in parallel, with the high and low pressure ends acting on the Bourdon tubes respectively. The deformation is transmitted to the gear mechanism through the pull rod, and the pointer displays the differential pressure.
Features: Bourdon tube has higher stiffness and strong overload resistance; Compact structure, suitable for high pressure differential or pulsating pressure scenarios (such as pump station outlet pressure monitoring).
Applicable scenario analysis
Double corrugated pipe structure
Typical applications:
Filter pressure loss monitoring: Measure the pressure difference before and after the filter screen to determine the degree of blockage.
Pipeline pressure loss analysis: Evaluate pipeline resistance and optimize fluid transport efficiency.
Liquid level measurement: Calculate the liquid level height inside the container through the static pressure difference of the liquid column.
Advantages: High precision (up to level 0.5), good stability, suitable for static or low flow rate scenarios.
Double Bourdon tube structure
Typical applications:
Pump station pressure control: Monitor the pressure difference between the pump outlet and inlet to prevent overload operation.
Gas flow measurement: Combined with throttling devices (such as orifice plates), calculate the flow rate through differential pressure.
Overpressure protection for sealed containers: Real time monitoring of pressure inside the container to ensure safe operation.
Advantages: High pressure resistance (nominal pressure up to 10MPa), strong impact resistance, suitable for dynamic or high-pressure scenarios.
Selection suggestions
Micro differential pressure measurement (<1kPa): Double corrugated tube structure is preferred, such as CYW-150B type, which has high sensitivity and stable zero position.
High pressure difference or pulsating pressure (>1MPa): Double Bourdon tube structure is selected, such as CB100 type, which has stronger overload resistance.
Corrosive medium: Both structures can use 316/316L stainless steel material, but the compatibility of the sealing components (such as fluororubber or polytetrafluoroethylene) needs to be confirmed.