The selection of a hydraulic pump solenoid valve should first follow four major principles: safety, reliability, applicability, and economy. After considering these principles, evaluate the six aspects of site conditions: piping parameters, fluid parameters, pressure parameters, electrical parameters, mode of operation, and any special requirements for the selection.
Selection basis:
1、 According to the pipeline parameters to choose the solenoid valve: diameter specifications (i.e. DN), interface mode
1) According to the site pipe diameter size or flow requirements to determine the through diameter (DN) size.
2) Interface mode, generally > DN50 to choose flange interface, ≤ DN50 can be freely selected according to user needs.
2、 According to the fluid parameters to choose the hydraulic pump solenoid valve: material, temperature group
1) corrosive fluids: Use a corrosion-resistant hydraulic pump solenoid valve and all stainless steel for general applications. For edible ultra-clean fluids, use a food-grade stainless steel hydraulic pump solenoid valve.
2) high-temperature fluid: to choose the use of high-temperature-resistant electrical materials and sealing materials manufactured by the hydraulic pump solenoid valve, and to choose the type of piston structure.
3) Fluid state: large to have a gas, liquid or mixed state, especially when the calibre is greater than DN25 must be distinguished;
4) Fluid viscosity: usually below 50cSt can be arbitrarily selected, if more than this value, the choice of high-viscosity hydraulic pump solenoid valve.
3、 According to the pressure parameters to choose the hydraulic pump solenoid valve: principle and structure varieties
1) Nominal pressure: this parameter is the same as the meaning of other general valves, according to the nominal pressure of the pipeline to determine.
2) Working Pressure: If the working pressure is low, you must choose the direct-acting or step-by-step direct-acting principle. For a low working differential pressure of more than 0.04 MPa, you can select direct-acting, step-by-step direct-acting, or pilot-type options.
4、 Electrical selection: voltage specifications should try to give priority to AC220V, DC24 is more convenient.
5、Choose according to the work time duration: normally closed, normally open, or continuously energized
1) When the hydraulic pump solenoid valve needs to remain open for a long time and the open duration exceeds the close time, select a normally open type.
2) If the opening time is short or the opening and closing time is not much, then choose the normally closed type.
3) However, for safety protection conditions like furnace or kiln flame monitoring, do not select normally open; instead, choose a type that remains energized for long periods.
6、 According to the environmental requirements to choose auxiliary functions: explosion-proof, check, manual, waterproof fog, water shower, diving.
Selection principles
Security:
1、 corrosive media: Use plastic or all stainless steel hydraulic pump solenoid valves as appropriate. For strong corrosive media, select an isolation diaphragm type. For neutral media, use copper alloy for the valve shell material in hydraulic pump solenoid valves. If you use a different material, the valve shell may rust and produce debris, especially in infrequent use situations. Ammonia valve can not use copper.
2、 explosive environment: must use the corresponding explosion-proof grade products, open-air installation or dusty occasions should be selected waterproof, dust-proof varieties.
3、 hydraulic pump solenoid valve nominal pressure should exceed the pipe to the high working pressure.
Applicability:
Media Characteristics
1) quality of gas, liquid or mixed state, respectively, choose different varieties of hydraulic pump solenoid valves.
2) medium temperature different specifications of the product, otherwise the coil will burn out, seals aging, seriously affecting the life of the life;
3) medium viscosity, usually below 50cSt. If this value is exceeded and the diameter is greater than 15mm, use a multi-function hydraulic pump solenoid valve. If the diameter is less than 15mm, use a high viscosity hydraulic pump solenoid valve.
4) If media cleanliness is low, equip the system with a backwash filter valve before the solenoid valve. For low-pressure conditions, choose a direct-acting diaphragm hydraulic pump solenoid valve.
5) If the medium is directional circulation, and does not allow backflow, need to use two-way circulation.
6) Choose the medium temperature within the allowable range of the solenoid valve.
Piping parameters
1) According to the requirements of the medium flow direction and pipeline connection mode to select the valve port and model;
2) Select the nominal diameter based on the flow rate and valve Kv value; you can also choose it according to the pipeline diameter.
3) working differential pressure: For a low working differential pressure of 0.04 MPa or more, select an indirect pilot type. For a low working differential pressure close to or less than zero, select a direct-acting or step-by-step direct type.
Environmental conditions
1) Select the maximum and minimum ambient temperatures within the permissible range.
2) In environments with high relative humidity, water droplets, or rain, select a waterproof hydraulic pump solenoid valve.
3) The environment is often vibration, bumps and shocks and other occasions should choose special varieties, such as marine solenoid valves.
4) In a corrosive or explosive environment, prioritize choosing a corrosion-resistant type according to safety requirements.
5) If the environmental space is restricted, choose a multi-function solenoid valve. This choice eliminates the need for a bypass and three manual valves. It also allows for easy online maintenance.
Power conditions
1) According to the type of power supply, the choice of AC and DC solenoid valves. Generally speaking, AC power supply is convenient to take; 2) The voltage specification as far as possible to give priority to the selection of AC220V.
2) Voltage specifications with as much as possible to give priority to the selection of AC220V.DC24V; 3) power supply voltage fluctuations usually AC choose +%10%.
3) power supply voltage fluctuations are usually selected AC +%10%. -15%, DC allows ±%10 or so, such as overshooting, must take measures to regulate the voltage.
4) Select according to the power capacity, rated current, and power consumption. In cases of insufficient capacity, prefer using indirectly guided hydraulic pump solenoid valves because the AC start VA value is higher.
Control accuracy
1) Ordinary hydraulic pump solenoid valves have only two positions: on and off. For high precision control and smooth parameter requirements, choose a multi-position hydraulic pump solenoid valve.
2) Action time: refers to the electrical signal connection or cut off to the main valve action completion time.
3) Leakage: the leakage value given on the sample for the common economic level.
Reliability:
1、 Working life, The factory does not include this in the test items; it belongs to the type test items. In order to ensure the quality should choose the brand products of regular manufacturers.
2、 Working system: long-term working system, repeated short-time working system and short-time working system. For a long time the valve is open only a short time to close the case, it is appropriate to use normally open hydraulic pump solenoid valve.
3、 Operating frequency: For high action frequency requirements, prefer a direct-acting solenoid valve structure and choose AC for power.
4、 Action reliability:Strictly speaking, Chinese professional standards for hydraulic pump solenoid valves do not formally include this test. To ensure quality, you should select products from reputable brand-name manufacturers. In some cases, where actions are infrequent but reliability requirements are very high, such as in fire and emergency protection, we must take them very seriously. For particularly important cases, take double insurance with two layers of protection.
Economy:
One of the criteria for its selection, but it must be economic on the basis of safety, applicability and reliability.
Economy involves more than just the selling price of the product. It also includes prioritizing the product’s function and quality. Additionally, consider the costs associated with installation, maintenance, and other required accessories.
More importantly, a hydraulic pump solenoid valve accounts for a negligible cost in the entire self-control system and even in the production line. Choosing to save a small amount of money and making a wrong selection could cause significant damage to the system.
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