Automatic Aerosol Filling Machines Automatic Aerosol Filling Machines,Fill-One Aerosol Filling Machine,Fill-One Aerosol Filling System,Automatic Aerosol Filling Production Jinhu Fuda Machinery Co.,Ltd , https://www.efuda.com
Correct choice of control valve and process pipe end connection form (ring connection / convex connection / clip type). When equipped with a flange, a gasket is required between the valve supplier and the mating flange supplied by the valve supplier and the required flange material, pressure rating and flanged pipe designation shall be indicated in the contract technical attachment. Clamp-type control valve itself, if there is a single flange, flange connection hole of the carrier thread should be metric, if the load on the thread for the English system, the valve supplier should be required to provide connection bolts. If the control valve is equipped with a solenoid valve, it is recommended that the technical parameters of the solenoid valve part in the technical annex of the contract indicate the manufacturer, brand, voltage level, explosion-proof type, material requirements and the travel time of the control valve on and off, The specific model of the solenoid valve shall be specified by the valve supplier according to the final calculation or factory test. However, it shall be indicated whether the supplier is allowed to use the solenoid valve as the pilot valve in the control circuit. In order to shorten the control valve travel time when the actuator of the control valve requires air volume, using the solenoid valve as a pilot valve in combination with a large-capacity pneumatic actuator reduces costs but also increases the number of accessories as the gas The increase in road links means an increase in the number of points of failure. Therefore, when discussing technical attachments, it should be determined whether to permit the use of the pneumatic control scheme. It is recommended that both the diaphragm actuator and the piston actuator be equipped with an air filter pressure reducer that will allow the actuator to be driven by the source of pressure. Prior to delivery, the control valve equipped with accessories should be connected in the factory complete, and tested to meet the technical requirements of the contract accessories. Control valve supplier should be based on the application of the valve, the connection pipe is to determine the pipe, PVC sheath or stainless steel pipe, according to the valve travel time requirements to determine the diameter of the gas pipe connection. General control valve gas pipe connection pipe diameter should not be less than 8 × 1mm, because too small will cause the control valve response speed is too slow, of course, if the control valve switch travel time allowed, you can also use the pipe diameter of 6 × 1mm gas connection pipe. The size of the control valve should be as close as possible to the design document and, if necessary, be communicated to the process piping, equipment and related professional engineers (if no change is allowed, the relevant professional should discuss the decision to change) The corresponding design changes. Should pay attention to the corrosion of the valve. If the purchased control valve cavitation, flash, cavitation, erosion and other issues, should pay attention to whether the appropriate treatment, whether to avoid these problems or minimize the possibility of these phenomena. Valve body, valve core, cage, seat ring material should be made of hard steel or alloy steel, or nitriding treatment or surface coating (such as Galilei too Levin). Control valves should be absolutely avoided cavitation under various application conditions. There must be a confirmation of the dimensions of the valve and the location of the accessories such as the positioner in the technical annex of the contract to determine whether there is any conflict between the installation space for the control valve and the available space for the attachment and the installation location on the drawing. If there is a conflict, we should first confirm whether to change the control valve actuator mounting position or valve attachment installation location and orientation. If the valve position can not be changed, should inform the process, piping, equipment, electrical and other professionals to modify the appropriate layout and design to move. The contractor shall be required to provide the material analysis report of the key components of the control valve, the control valve leakage test report, the pressure test report, the formation of the test report or certificate of conformity, the gas connection diagram, the pressure control procedures and methods Test control valve leakage test procedures, methods, in order to check, review. The bidder shall require the bidder to provide the selection of the control valve sample (the specific model code in the sample, the acronym should be described in detail), the application performance. Technical contract should be required to provide the contractual parties to the valve body and its accessories routine maintenance manuals, accessories, agents and distributors of the contact address, fax, telephone number. The degree of protection of the control valve attachment should not be less than IP54 / NEMA4 (digital valve positioners are generally IP65 / NEMA4X). The inlet and outlet ports of the junction box should be sealed. The application valve number of the control valve should be reflected on the nameplate of the valve or be separately marked on a brand and be fixed on the valve. In addition to the double flow outward, the valve body should clearly marked the direction of the medium allowed to pass the valve. Should be based on the control valve applications and the criticality to consider whether to set the hand wheel. The supplier of the control valve shall be required to provide the dead zone parameters of the valve and the basic error parameters of the control valve of the power distribution / gas valve positioner. Generally, the dead zone parameter of the valve should not exceed 2%. The basic error of the control valve of the power distribution / gas valve positioner should be less than ± 10%. If the digital valve positioner is used, the basic error of the control valve should be less than ± 1% . Should pay attention to the control valve on the air pressure requirements. According to the actual situation of the device, check the control valve actuator on the instrument air pressure requirements. If the instrument air pressure in the device does not meet the requirements of the implementing agencies, the valve supplier should replace the implementing agencies, at the same time, should provide high-quality instrument air, at a minimum should meet the following requirements: Clean, dry, does not contain significant corrosive Impurities, the gas containing solid particles less than 0.1g / m3, the particle diameter of not more than 3μm, the oil content of not more than 1 × 10 (-6 power), according to statistics, due to poor gas source locator does not work properly accounted for Locator failure rate of more than 60%. The design staff of the general design unit has selected the material of the valve body core (valve core, valve seat, valve stem, cage, seat ring, packing, gasket). Final valve material selection should be consistent with the design requirements, if inconsistent, you must confirm the material changes after the appropriate, in case of doubt, you must make technical clarifications. When the control valve arrives, the supplier shall promptly inform the supplier of the time required for opening the container. The supplier is required to send personnel to participate in the commodity inspection. If the supplier sends a fax or a letter of confirmation, it confirms the user's unpacking result. Commodity inspection personnel shall record all the commodity inspection results in detail and shall not omit any details. The inspection results shall be compared with the technical attachment of the contract, the deviation shall be recorded, feedback to the supplier together with the commodity inspection report in time, and the timely processing shall be required. As far as possible not delay the inspection time, otherwise it may affect the claims and progress of the project. Another thing to note is that the valve number, body, actuator and accessories model, serial number and other parameters should be recorded for the record for future use accessories to order accessories. Because if you do not write down these parameters in a timely manner, after a long period of use of the control valve, the nameplate parameters will be blurred, difficult to identify, may also be the nameplate is lost, and some parameters for the purchase of spare parts is necessary. When ordering software required for a digital positioner, simply state the name of the software and indicate the latest version at the time of delivery, and the version number of the software may not be written. Spare parts and control valves ordered together, saving costs, the number of procurement spare parts to 1 to 2 years to meet the normal production needs of the principle. If the use of the components of the control valve is unclear, the supplier may be asked to recommend it, taking into account the financial considerations. Do not bundle the tender. If two or more different types of goods are purchased together with a control valve, it is very difficult to unpack them if both good and cheap goods in one package have poor or very expensive goods Two full choice. It is suggested that the payment and delivery progress, product quality, service linked to set aside a certain amount of insurance money for the supplier to provide product quality and service quality assessment. If the medium through the control valve is a one-way flow, the control valve must not be installed in reverse direction, otherwise it will affect the valve's flow capacity, flow characteristics, sealing performance and stability of operation. At the time of signing the contract, the technical annex of the contract should be made clear that when the supplier supplied the product can not be used normally or fails, the supplier shall promptly debug the provided products, deal with the existing problems or replace , And provide temporary substitutes, shall not be delayed for any reason to affect the normal production of the user, otherwise the quality of service will be held accountable supplier responsibility; once the problem is solved, the costs incurred should be identified after the reasons, The two sides discussed to solve. Control valve attachment port entry line should be bottom-up access, should not be reversed to prevent water damage to parts. If the cable must be accessed from top to bottom, the cable should be lengthened appropriately to ensure a U-shaped bend before entering the terminal. So that rain will not enter the auxiliary instrument. If threading is used, a drain should be left in the lower part of the U-bend. When the cable leads from the instrument cable tray, pay attention to the direction of the thread pipe on the interface of the cable tray. The nozzle should never be upward; and the nozzle should be sealed to eliminate the possibility of water inflow. Control valve type, material, connection with the pipeline, the choice of accessories, the preparation of the tender documents, bid evaluation, the signing of the technical contract, installation and maintenance is a tedious and complex process, any loopholes in the link may affect Control valve use. Although there are a variety of books, standards and software for designers and users of technical staff reference, generally not much difficulty, but from process designers to propose process parameters to prepare the control valve of the tender documents, the tender , Bid evaluation, technical clarification, formation of bid evaluation report, approval of bid evaluation report, technical negotiation, signing of technical contract, unpacking inspection, installation, commissioning and put into use, generally takes a long time, Neglecting or missing one or more items may cause loss to the factory and affect the progress of the project. This article only in Anhui Huaihua Group Co., Ltd. several procurement control valve and the use of some of the experience and knowledge of the summary, it is recommended to purchase control valve should have sufficient time, as long as the technical conditions are met, we should advance the tender documents Preparation, bid evaluation, technical clarification, signing of technical contracts and other work, the real work to do small and deep, less technical flaws. As for the progress of business contracts, we must decide according to the progress of the project and the funding situation.