Four six principles to pay attention to when purch

The four and six principles that should be paid attention to in the selection of solenoid valves

the selection of solenoid valves should first follow the four principles of safety, reliability, applicability and economy, and then choose according to six aspects of on-site working conditions (namely pipeline parameters, fluid parameters, pressure parameters, electrical parameters, action mode and special requirements)

selection basis:

first, select the solenoid valve according to the pipeline parameters: diameter specification (i.e. DN), interface mode

1. Determine the diameter (DN) size according to the on-site pipeline inner diameter size or flow requirements

2. Interface mode. Generally, flange interface should be selected if it is>dn50, and it can be freely selected if it is ≤ DN50

II. Select solenoid valve according to fluid parameters: material, temperature group

1. Corrosive fluid: corrosion-resistant solenoid valve and all stainless steel should be selected; Edible ultra clean fluid: food grade stainless steel solenoid valve should be selected

2. High temperature fluid: choose solenoid valves made of high temperature resistant electrical materials and sealing materials, and choose piston structure type. 4. Force value accuracy: better than ± 1% of the measured force value

3. Fluid state: it can be as large as gas state, liquid state or mixed state, especially when ordering with a diameter greater than DN25

4. Fluid viscosity: generally, you can choose any value below 50cst. If it exceeds this value, you should choose high viscosity solenoid valve

III. select the solenoid valve according to the pressure parameters: principle and structure variety

1. Nominal pressure: this parameter has the same meaning as other general-purpose valves, and is determined according to the pipe function and characteristics: adopt high-precision, full digital speed regulation system and fine reducer nominal pressure

2. Working pressure: if the working pressure is low, the direct acting or step-by-step direct acting principle must be selected; When the minimum working pressure difference is above 0.04MPa, the direct acting, step-by-step direct acting and pilot type can be selected

IV. electrical selection: AC220V and DC24 should be preferred for voltage specification as much as possible

v. it should be selected according to the continuous working time: normally closed, normally open, or continuously energized

1. When the solenoid valve needs to be opened for a long time, and the continuous time is more than the closing time, it should be normally open

2. If the opening time is short or the opening and closing time is not long, choose the normally closed type

3. However, some working conditions for safety protection, such as furnace and kiln flame monitoring, should not be normally open, but should be long-term energized

VI. select auxiliary functions according to environmental requirements: explosion-proof, check, manual, waterproof fog, water drenching, diving

1. Explosive environment: solenoid valves with corresponding explosion-proof grade must be selected (our company has: diibt4, diict5, exmi/iit4)

2. When the fluid in the pipe has backflow, our ok71-n and ok72-n series solenoid valves with check function can be selected

3. When it is necessary to carry out on-site manual operation on the solenoid valve, our company ok7 can be selected. Therefore, the oil refining enterprises have been cancelled by the state. 1-s and ok72-s series solenoid valves with manual function

4. Waterproof should be selected for outdoor installation or dust prone occasions. The difference between it and conventional electronic universal testing machine is that its control mode can be load controlled dust type (protection grade is above IP54)

5. Submersible solenoid valve (protection grade above IP68) must be used for fountain