M-IV Active Gas Pressure Tester Product Introduction
The active gas pressure tester serves as both the driving force for gas emission and outburst and a calibration parameter. Accurately measuring coal seam gas pressure is crucial for reasonably and effectively formulating mine gas control measures and predicting the risk of coal and gas outbursts. Currently, most commonly used coal seam gas pressure measurement techniques are effective under conditions where the rock formation in the sealing section is hard and dense. However, due to limitations in sealing materials, the sealing effect is often unsatisfactory in soft sandstone or when micro-fractures exist around the borehole, leading to gas leakage. This results in measured gas pressure values being lower than the actual gas pressure in the coal seam, which can lead to erroneous judgments and cause **
M-IV Active Gas Pressure Tester Equipment Principle
The active pressure measurement sealing method was first proposed by Academician Zhou Shining of the Chinese Academy of Sciences as a method for measuring coal seam gas pressure. The principle of this sealing method involves using expansion rubber at both ends of the sealing section and injecting a sealing slurry with a pressure slightly higher than the coal seam gas pressure in the middle. Under pressure, the slurry can not only penetrate into the fractures between the borehole wall and the rubber but also seep into the fractures of the pressure relief zone around the borehole and natural fractures in the surrounding area, preventing gas leakage. This forms an active sealing method where the rubber seals the slurry, and the slurry seals the gas, ensuring that the measured gas pressure equals the actual gas pressure in the coal seam. Our company has upgraded and improved this product multiple times, making it easier to install and use.
After the sealing process is completed, inert gas is actively injected into the gas pressure measurement chamber, and the measured value represents the actual gas pressure of the coal seam. The active pressure measurement sealing method significantly shortens the testing time, with each test point taking no more than 3 days, which is 1/10 to 1/5 of the testing time of conventional pressure testers. This tester uses new sealing materials and is suitable for directly measuring gas pressure in coal seam roadway layers. The instrument is user-friendly, easy to operate, fast in measurement, convenient to transport, accurate in results, and simple to maintain. It is reusable and cost-effective.
M-IV Active Gas Pressure Tester Technical Parameters
Rated pressure: 6MPa (6-20MPa, customizable)
Sealing borehole diameter: ∮50—55mm, or ∮70—90mm
Sealing depth: 15--20m
Sealing length: 6--10m
Sealing slurry section length: 2--6m
Dimensions: ∮42×2000 mm or ∮63×2000 mm
Sealing slurry composition: Bentonite + water
Coal seam firmness coefficient in the sealing section: f≥0.5
Measurement time: Generally 2—4 days
Length per steel pipe section: 2—2.35m
Main unit dimensions (L×W×H): 450×300×580mm
Weight: 50Kg

Zhengzhou Aidi ProductionActive Gas Pressure TesterSupplies Coal Drill Cuttings Desorption Tester, Deep Hole Sampling Device, Pressure Tester, Geological Exploration Desorption Tester, Borehole Flow Meter, Mine Extraction and Outburst Prevention Equipment, Coal True Density Tester, Gas Content Tester, Automatic Gas Emission Initial Velocity Tester, Diffusion Velocity Tester, Coal Extraction Pipeline Gas Parameter Tester