Abstract: A positioning device of a position sensor that does not require re-positioning and re-fastening at the time of mounting the position sensor. A positioning tool provided with a driving section and a positioning section is mounted on a position sensor. Then, positioning projections of the positioning section are engaged with neutral position grooves. In this state, the positioning section is rotated by the driving section so as to have the position sensor rotated together until the R-contact turns ON, so that an angle from N to R, i.e. from a neutral position to a reverse contact ON position is measured. Thereafter, the positioning section is rotated in an opposite direction to measure an angle from N to D, i.e. from a reverse contact OFF position to a drive contact ON position. Based on the measurement result, the positioning section is re-rotated by the driving section to move the position sensor to a proper neutral position. The position sensor is fastened in this condition.

Abstract: A process for inhibiting polymerization of an aromatic vinyl compound during the stage of producing, purifying, storing or transporting the aromatic vinyl compound which not only inhibits an initial polymerization but also inhibits polymerization efficiently over a long period of time and which is excellent in handleability. The process involves the step of adding a nitrogenous aromatic compound in combination with a sulfonic acid compound to the aromatic vinyl compound during the production, purification, storage of transportation thereof.

Abstract: A process for inhibiting polymerization of an aromatic vinyl compound during the stage of producing, purifying, storing or transporting the aromatic vinyl compound which not only inhibits an initial polymerization but also inhibits polymerization efficiently over a long period of time and which is excellent in handleability. The process involves the step of adding a nitrogenous aromatic compound in combination with a sulfonic acid compound to the aromatic vinyl compound during the production, purification, storage of transportation thereof.

Abstract: A process for inhibiting polymerization of an aromatic vinyl compound during the stage of producing, purifying, storing or transporting the aromatic vinyl compound which not only inhibits an initial polymerization but also inhibits polymerization efficiently over a long period of time and which is excellent in the handleability. The process involves the step of adding a nitrogenous aromatic compound in combination with a sulfonic acid compound to the aromatic vinyl compound during the production, purification, storage of transportation thereof.

Abstract: A positioning device of a position sensor that does not require re-positioning and re-fastening at the time of mounting the position sensor. A positioning tool provided with a driving section and a positioning section is mounted on a position sensor. Then, positioning projections of the positioning section are engaged with neutral position grooves. In this state, the positioning section is rotated by the driving section so as to have the position sensor rotated together until the R-contact turns ON, so that an angle from N to R, i.e. from a neutral position to a reverse contact ON position is measured. Thereafter, the positioning section is rotated in an opposite direction to measure an angle from N to D, i.e. from a reverse contact OFF position to a drive contact ON position. Based on the measurement result, the positioning section is re-rotated by the driving section to move the position sensor to a proper neutral position. The position sensor is fastened in this condition.

Abstract: According to the present invention, there is provided a process for inhibiting polymerization of an aromatic vinyl compound during the stage of producing, purifying, storing or transporting the aromatic vinyl compound which not only inhibits an initial polymerization but also inhibits efficiently polymerization over a long period of time and which is excellent in the handleability. The present invention relates to a process for inhibiting polymerization of an aromatic vinyl compound which comprises adding a nitrogenous aromatic compound in combination with a sulfonic acid compound to the aromatic vinyl compound during the production, purification, storage or transportation.

Abstract: [PROBLEMS] To provide: a method by which the generation of a copolymer of an aromatic vinyl compound and either the divinylbenzene generated in the production of the aromatic vinyl compound or the divinylbenzene which has come into the system together with a raw material for the aromatic vinyl compound is inhibited in the steps of distilling, purifying, and storing the aromatic vinyl compound: and a method of inhibiting the copolymer from depositing on and thus fouling devices and facilities. [MEANS FOR SOLVING PROBLEMS] The method of inhibiting the generation of a copolymer of divinylbenzene and an aromatic vinyl compound is characterized in that a dinitrophenol compound (A), a sulfonic acid compound (B), and a p-phenylenediamine compound (C) are simultaneously used in the steps of producing, purifying and storing the aromatic vinyl compound.

Abstract: According to the present invention, there is provided a process for inhibiting the polymerization of an aromatic vinyl compound which is capable of efficiently inhibiting the polymerization of an aromatic vinyl compound not only in an initial stage but also over a long term in the stage of producing, purifying, storing or transporting the aromatic vinyl compound, and which is excellent in handling. The present invention relates to a process for inhibiting the polymerization of an aromatic vinyl compound which requires the step of adding a 2-nitrophenol compound in combination with a sulfonic acid compound to the aromatic vinyl monomer during the stage of producing, purifying, storing or transporting the aromatic vinyl compound.

Abstract: According to the present invention, there are provided a polymerization inhibitor which is easy to handle and which has a little toxicity and a high polymerization-inhibitory effect toward an aromatic vinyl compound and a process for inhibiting the polymerization of the aromatic vinyl compound. The present invention relates to a polymerization inhibitor for the aromatic vinyl compound which comprises contain two ingredients of a specific quinone methide compound and a specific organic sulfonic acid compound, and to a process for inhibiting polymerization of the aromatic vinyl compound which comprises adding a specific quinone methide compound and a specific organic sulfonic acid compound simultaneously or further a specific quinone methide compound, a specific organic sulfonic acid compound and a specific N-oxyl compound simultaneously in the stage of producing, purifying, storing or transporting the aromatic vinyl compound.

Abstract: According to the present invention, there is provided a process for inhibiting the polymerization of an aromatic vinyl compound which is capable of efficiently inhibiting the polymerization of an aromatic vinyl compound not only in an initial stage but also over a long term in the stage of producing, purifying, storing or transporting the aromatic vinyl compound, and which is excellent in handling.

Abstract: An inhibitor to suppress or inhibit the viscosity increase of a hydrocarbon, e.g. in a bottom section of an oil quench tower, featuring the use of a sulfonic acid and/or its salt as an effective inhibitor composition, which may optionally contain a polymerization inhibitor including one or more inhibitors selected from the group of aromatic amines, phenols and dialkyl hydroxyl amines. Furthermore, the method to inhibit the increasing viscosity of hydrocarbon, e.g. in a bottom section of a tower, may be accomplished by adding the hydrocarbon viscosity inhibitor to the feed oil, reflux oil or directly to the tower bottom oil in the tower. Such an oil quench tower is used for an olefin production process in which the hydrocarbon may include naphtha, light oil, natural gas, liquefied natural gas, etc. in the raw material.