Precise pressure regulating valve

Abstract

The invention discloses a precise pressure regulating valve. The precise pressure regulating valve comprises a regulating screw rod, a valve sleeve, a valve body, a diaphragm, a nozzle, a centre and a centre seat, under the condition of certain input pressure, the regulating screw rod compresses a first elastic piece according to the required output pressure, so that pressure is applied to the diaphragm, the pressure is transmitted to a second elastic piece through the centre and the centre seat, the second elastic piece is compressed, the centre seat drives a sealing element to move downwards, so that a gap is formed between the center seat and the nozzle, input gas flows through the gap between the centre seat and the nozzle, the pressure is changed, the gas entering the lower chamber of the diaphragm generates acting force on the diaphragm, the pressure of the whole system is balanced, and at the moment, the output pressure of the gas is the needed output pressure. According to the precise pressure regulating valve, the diaphragm made of stainless steel is adopted as the elastic element, the dead volume is small, the balance speed is high, the use temperature range is wide, and the performance is stable; and the diaphragm is made of stainless steel, so that the generation of volatile substances is avoided, and the accuracy of experimental results is improved.

Description

technical field [0001] The invention relates to the technical field of instrument gas circuit control, in particular to a precision pressure regulating valve. Background technique [0002] Gas chromatography is a column chromatography with gas as the mobile phase. The fluidity is the carrier gas. The carrier gas passes through the gasification chamber to mix with the vaporized sample, and the sample gas is brought into the chromatographic column for separation. The separated components flow into the detector successively with the carrier gas, and then the carrier gas is emptied. The detector converts the change of the concentration or mass of the substance into a certain electrical signal, which is amplified and recorded on the recorder, usually with a magnification of 10 10 , the chromatographic elution curve is obtained. Under such a large magnification, small airflow changes will also affect the experimental results, so there are professional requirements for the carrie...

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Problems solved by technology

[0003] The valve body used in the gas path control of the detector in the prior art has a large dead volume, poor balance speed and adjustment linearity, and is prone to volatile substances, causing pressure fluctuations in the gas path, which can easily affect the experimental results and reduce the accuracy of the experimental results. Spend

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