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I. Basic aspects of valve design As an important component of pipeline systems, valves must ensure the safe and reliable fulfillment of the requirements imposed on them by those systems. Therefore, valve design must meet all the requirements imposed on valves by the pressure, temperature, corrosion, and fluid properties of the working medium, as well as considerations related to operation, manufacturing, installation, and maintenance. Valve design must specify the given technical data, namely the “design inputs,” on which a correct design can be carried out. Basic data that must be available for the “design input” of a valve: 1) The purpose or type of the valve ； 2) Operating pressure of the medium ； 3) Operating temperature of the medium ； 4) Physical and chemical properties of the medium (corrosivity, flammability and explosiveness, toxicity, state of matter, etc.) ； 5) Nominal diameter ； 6) Knot length ； 7) Connection method with pipes ； 8) Operation mode of the valve (manual, gear drive, worm gear drive, electric, pneumatic, hydraulic, etc.). The data and technical requirements that should be understood when designing valve technology and working drawings include: 1) the flow capacity of the valve and the fluid resistance coefficient ； 2) Valve opening and closing speed and number of operations ； 3) Energy characteristics of the drive device (AC or DC, voltage, air pressure, etc.) ； 4) Valve operating environment and maintenance conditions (whether it is explosion-proof, whether it is in a tropical climate, etc.) ； 5) Restrictions on external dimensions ； 6) Weight limit ； 7) Seismic resistance requirements. II. Valve Design Procedure 1. Design and Development Planning 1) Design and Development Phase ； 2) Review, verification, and validation activities suitable for each design and development phase ； 3) Responsibilities and authorities for design and development. 2. Design and development inputs 1) Functional and performance requirements: 2) Applicable legal and regulatory requirements ； 3) Information provided by previous similar designs ； 4) Other requirements necessary for design and development. 3. Output of design and development 1) meets the requirements of design and development inputs ； 2) Provide appropriate information on procurement, production, and service delivery ； 3) Include or reference product acceptance criteria ； 4) Specify the product characteristics necessary for the safety and proper use of the product. 4. Design and development review 1) Assess the ability of the design and development outcomes to meet requirements ； 2) Identify any issues and propose necessary measures. 5. Verification of design and development 1) Calculations using transformation methods ； 2) Comparison with proven similar designs ； 3) Testing and demonstration. 6. Design and development validation is carried out through product qualification. 7. Changes to design and development.