Process Engineering Division – Instrumentation and Automation Section – Daily Question – Question dated 2020-08-23

Since the pressure guiding tube is in direct contact with the process medium, the selection of such a tube depends on the physical and chemical properties of the medium being measured as well as the operating conditions; therefore, seamless steel tubes should be used. 1. Pressure transmitters, orifice plates, etc., are used in the measurement of medium and low-pressure media; the commonly used gauge pressure tube specification is Φ14×2mm carbon steel seamless pipe, with Φ18×2mm or Φ18×3mm also being used at times. 2. For analysis sampling pipes, seamless steel tubes with a diameter of Φ14×2mm are commonly used; sometimes pressure guiding tubes with diameters of Φ10×1.5mm, Φ10×1mm, or Φ12×1mm are also employed. 3. Under high-pressure operating conditions of over 10 MPa, seamless steel pipes or seamless alloy steel pipes with dimensions of Φ14×4 mm or Φ15×4 mm are commonly used. The material of the pressure guide tube depends on the corrosivity of the medium being measured, and it is usually the same as the material of the pipeline. 1. For media that do not cause corrosion, the most cost-effective carbon steel seamless tubes are usually used as instrument pressure transfer tubes. 2. For media with slight corrosion or no corrosion, acid-resistant stainless steel 1Cr18Ni9Ti should be used for the instrument pressure guiding tubes. 3. For highly corrosive media, such as in urea production, it is required that the instrument pressure guiding tubes be made of 316L or molybdenum-containing stainless steel tubes. 4. When measuring highly corrosive substances such as chlorine or hydrogen chloride, plastic pipes must be used for the instrument’s pressure conduits.

Since the pressure guiding tube is in direct contact with the process medium, the selection of such a tube depends on the physical and chemical properties of the medium being measured as well as the operating conditions; therefore, seamless steel tubes should be used. 1. Pressure transmitters, orifice plates, etc., are used in the measurement of medium and low-pressure media; the commonly used gauge pressure tube specification is Φ14×2mm carbon steel seamless pipe, with Φ18×2mm or Φ18×3mm also being used at times. 2. For analysis sampling pipes, seamless steel tubes with a diameter of Φ14×2mm are commonly used; sometimes pressure guiding tubes with diameters of Φ10×1.5mm, Φ10×1mm, or Φ12×1mm are also employed. 3. Under high-pressure operating conditions of over 10 MPa, seamless steel pipes or seamless alloy steel pipes with dimensions of Φ14×4 mm or Φ15×4 mm are commonly used. The material of the pressure guide tube depends on the corrosivity of the medium being measured, and it is usually the same as the material of the pipeline. 1. For media that do not cause corrosion, the most cost-effective carbon steel seamless tubes are usually used as instrument pressure transfer tubes. 2. For media with slight corrosion or no corrosion, acid-resistant stainless steel 1Cr18Ni9Ti should be used for the instrument pressure guiding tubes. 3. For highly corrosive media, such as in urea production, it is required that the instrument pressure guiding tubes be made of 316L or molybdenum-containing stainless steel tubes. 4. When measuring highly corrosive substances such as chlorine or hydrogen chloride, plastic pipes must be used for the instrument’s pressure conduits.

Depending on the degree of corrosion of the medium, 20# steel or 1Cr18Ni9Ti, acid-resistant stainless steel seamless tubes, are commonly used. The commonly used specifications are: Φ22*3, Φ18*5, Φ22*5, Φ18*3, Φ14*3, Φ14*2, etc.

Depending on the degree of corrosion of the medium, 20# steel or 1Cr18Ni9Ti, acid-resistant stainless steel seamless tubes, are commonly used. The commonly used specifications are: Φ22*3, Φ18*5, Φ22*5, Φ18*3, Φ14*3, Φ14*2, etc.

Depending on the degree of corrosion of the medium, 20# steel or 1Cr18Ni9Ti, acid-resistant stainless steel seamless pipes are commonly used. The commonly used specifications are: Φ22*3, Φ18*5, Φ22*5, Φ18*3, Φ14*3, Φ14*2, etc.

φ12*2, stainless steel 304. φ14*2, stainless steel 304

Since the pressure guiding tube is in direct contact with the process medium, the selection of such a tube depends on the physical and chemical properties of the medium being measured as well as the operating conditions; therefore, seamless steel tubes should be used. 1. Pressure transmitters, orifice plates, etc., are used in the measurement of medium and low-pressure media; the commonly used gauge pressure tube specification is Φ14×2mm carbon steel seamless pipe, with Φ18×2mm or Φ18×3mm also being used at times. 2. For analysis sampling pipes, seamless steel tubes with a diameter of Φ14×2mm are commonly used; sometimes pressure guiding tubes with diameters of Φ10×1.5mm, Φ10×1mm, or Φ12×1mm are also employed. 3. Under high-pressure operating conditions of over 10 MPa, seamless steel pipes or seamless alloy steel pipes with dimensions of Φ14×4 mm or Φ15×4 mm are commonly used. The material of the pressure guide tube depends on the corrosivity of the medium being measured, and it is usually the same as the material of the pipeline. 1. For media that do not cause corrosion, the most cost-effective carbon steel seamless tubes are usually used as instrument pressure transfer tubes. 2. For media with slight corrosion or no corrosion, acid-resistant stainless steel 1Cr18Ni9Ti should be used for the instrument pressure guiding tubes. 3. For highly corrosive media, such as in urea production, it is required that the instrument pressure guiding tubes be made of 316L or molybdenum-containing stainless steel tubes. 4. When measuring highly corrosive substances such as chlorine or hydrogen chloride, plastic pipes must be used for the instrument’s pressure conduits.

Since the pressure guiding tube is in direct contact with the process medium, the selection of such a tube depends on the physical and chemical properties of the medium being measured as well as the operating conditions; therefore, seamless steel tubes should be used. 1. Pressure transmitters, orifice plates, etc., are used in the measurement of medium and low-pressure media; the commonly used gauge pressure tube specification is Φ14×2mm carbon steel seamless pipe, with Φ18×2mm or Φ18×3mm also being used at times. 2. For analysis sampling pipes, seamless steel tubes with a diameter of Φ14×2mm are commonly used; sometimes pressure guiding tubes with diameters of Φ10×1.5mm, Φ10×1mm, or Φ12×1mm are also employed. 3. Under high-pressure operating conditions of over 10 MPa, seamless steel pipes or seamless alloy steel pipes with dimensions of Φ14×4 mm or Φ15×4 mm are commonly used. The material of the pressure guide tube depends on the corrosivity of the medium being measured, and it is usually the same as the material of the pipeline. 1. For media that do not cause corrosion, the most cost-effective carbon steel seamless tubes are usually used as instrument pressure transfer tubes. 2. For media with slight corrosion or no corrosion, acid-resistant stainless steel 1Cr18Ni9Ti should be used for the instrument pressure guiding tubes. 3. For highly corrosive media, such as in urea production, it is required that the instrument pressure guiding tubes be made of 316L or molybdenum-containing stainless steel tubes. 4. When measuring highly corrosive substances such as chlorine or hydrogen chloride, plastic pipes must be used for the instrument’s pressure conduits.

Depending on the degree of corrosion of the medium, 20# steel or 1Cr18Ni9Ti, acid-resistant stainless steel seamless tubes, are commonly used. The commonly used specifications are: Φ22*3, Φ18*5, Φ22*5, Φ18*3, Φ14*3, Φ14*2, etc

Depending on the degree of corrosion of the medium, 20# steel or 1Cr18Ni9Ti, acid-resistant stainless steel seamless tubes, are commonly used. The commonly used specifications are: Φ22*3, Φ18*5, Φ22*5, Φ18*3, Φ14*3, Φ14*2, etc.