초록 ▼

A flow meter tube is provided having improved performance in the measurement of the flow rate of erosive material. The internal wall surface of the flow meter tube has a smooth erosion-resistant coating thereon to protect the flow meter wall from erosion by the erosive fluid flowing there through.

A flow meter tube is provided having improved performance in the measurement of the flow rate of erosive material. The internal wall surface of the flow meter tube has a smooth erosion-resistant coating thereon to protect the flow meter wall from erosion by the erosive fluid flowing there through. The coating has a Rockwell C hardness of 56 to 70 and a surface roughness of less than or equal to 250 microinches rms.

대표청구항 ▼

What is claimed is: 1. A flowmeter tube for use in measuring the flow rate of erosive materials, the flowmeter tube comprising: a tube having a wall forming an inlet section having a first cross sectional area for receiving flowing erosive materials and an outlet section having a second cross secti

What is claimed is: 1. A flowmeter tube for use in measuring the flow rate of erosive materials, the flowmeter tube comprising: a tube having a wall forming an inlet section having a first cross sectional area for receiving flowing erosive materials and an outlet section having a second cross sectional area for receiving said flowing erosive materials from the inlet portion; wherein the first cross sectional area is larger than said second cross sectional area; a first pressure tap communicating with said inlet section; a second pressure tap communicating with said outlet section; said wall having an inside coating of tungsten carbide cemented by a nickel chromium alloy; said coating metallurgically bonded to said wall and having a hardness of Rockwell 56 to 70 and a surface roughness of less than or equal to 250 microinches rms. 2. The flowmeter according to claim 1, wherein the coating has a Rockwell C hardness of 64 to 70. 3. The flowmeter according to claim 1, wherein the coating has a thickness of 0.015 to 0.120 inches. 4. The flowmeter according to claim 1, wherein the surface roughness of the coating is less than or equal to 125 microinches rms. 5. The flowmeter according to claim 1, wherein the first and the second pressure taps are formed by electric discharge machining a hole through said coating and said wall. 6. The flowmeter according to claim 1, wherein the coating has an erosion rate of equal to or less than 0.041 mm3/g (ASTM G76). 7. The flowmeter according to claim 1, wherein the coating has an erosion rate of equal to or less than 0.025 mm3/g (ASTM G76). 8. In a pipeline transporting a flowing erosive slurry, a flowmeter tube having the erosive slurry flowing there through, wherein the flowmeter tube comprises: a wall forming inlet section having a first cross sectional area for receiving the flowing erosive slurry from said pipeline and an outlet section having a second cross sectional area for receiving the flowing erosive slurry from said inlet section; said wall having an inside coating of tungsten carbide cemented by a nickel chromium alloy contacting the erosive flowing slurry to protect the wall from erosion by the erosive slurry; wherein said coating is autogenously, metallurgically bonded to said wall, has a hardness of 64 to 70 Rockwell C, a surface roughness of less than or equal to 250 microinches rms, and an erosion rate of equal to or less than 0.025 mm3/g (ASTM G76); a first pressure tap communicating through said wall and said coating at said inlet section; and a second pressure tap communicating through said wall and said coating at said outlet section; wherein said first and said second pressure taps provide pressure data to determine the flow rate of the erosive slurry flowing through the pipeline. 9. The flowmeter according to claim 8, wherein the flowmeter tube is a venturi flowmeter tube.