This is an informational post, please check the Rexroth solenoid products page if you are searching for the product.

Bosch Rexroth is supplying safe, accurate, efficient and cost-effective drive and control technology for a variety of machinery and system devices. Rexroth solenoid valve is a typical application of Bosch Rexroth technology. As we all know, the Rexroth solenoid valve has a wide application in the hydraulic system, machinery, and many other industries. How to select Rexroth solenoid valve? There are 4 aspects should be taken into consideration including safety, applicability, reliability, and economy.

Safety

  1. Corrosive medium: PTFE or all stainless steel is more suitable for the solenoid valve. Diaphragm sealed solenoid valve is necessary for the strong corrosive medium. The copper alloy will be the perfect materials for the neutral medium solenoid valve, or valve shell often fall rust particles, especially for the occasions with infrequent action. Ammonia valve should not adopt copper.
  2. Explosive atmosphere: select explosion-proof solenoid valve with the relative explosive-proof grade. For the open-air environment or dust environment, water-proof solenoid valve or dust-proof solenoid valve will be proper.
  3. Pressure: the nominal pressure of solenoid valve should more than the maximum working pressure pipe.

Applicability

  1. medium characteristic
  • Gaseous, liquid or mix state should select different solenoid valves.
  • Medium temperatures are different for solenoid valve of different specifications or the solenoid coil will be burnt out, seal aging, and have a bad influence on the service life of solenoid valve.
  • Medium viscosity is usually below 50cSt. If the value is over 50cSt, and the size of the solenoid valve is bigger than 15mm, we should select multi-function solenoid valve. When the size of the solenoid valve is less than 15mm, high-viscosity solenoid valves are favorable.
  • When the medium cleanliness is low, bounce-back strainer valve should be installed on the solenoid valve.
  • If the medium is directional flow, and backflow is not allowed, we should select the two-way flow of solenoid valve.
  • Medium temperature is selected within the solenoid valve allowance.
  1. Tube parameter
  • Select the size and models of the solenoid valve according to the medium flow direction and connection method between tubes.
  • Select the inside nominal diameter or internal diameter of the pipeline according to the flow and Kv value of valve.
  • Operating pressure differential: when the minimum operating pressure differential is over 0.04Mpa, we can select indirect piloted valve. When the minimum operating pressure differential is near to or less than zero, we can select direct-acting solenoid valve or distributed direct type solenoid valve.
  1. environmental conditions
  • Select the maximum and minimum temperature within the allowable range;
  • Select water-proof solenoid valve in the environment of high relative humidity and raining;
  • Select special solenoid valve like marine solenoid valve in the environment of vibration, jolt and impulsion;
  • Select corrosion-resistant type solenoid valve in the environment of corrosively and explosiveness;
  • If the environment is limited, we should select multi-function solenoid valve because it is easy to maintain.
  1. power conditions
  • Select AC or DC solenoid valve according to the power system. Ac power source is more convenient.
  • As for the voltage specification, AC220V and DC24V should be prioritized.
  • mains voltage fluctuation must be within the allowance, AC(±10~15%), DC(±10%), if the mains voltage fluctuation is out of tolerance, voltage regulator measure should be taken.
  • Select the power capacity according to the rated current and dissipated power.
  1. control precision
  • For the common solenoid valve, there are two positions including on and off. Based on the high requirement of control precision and steady parameter, we should select multiple positions solenoid valve.
  • Actuation time means the time taken from turning on or off the electrical signal to the actuation of the main valve is completed. It is an important standard to select solenoid valve.
  • Leakage is also a marker, the leakage value in the sample is common economic class.

Reliability

  1. Service life: it is generally not on the list of factory test projects. For ensuring its quantity, please select the formal election of the brand manufacturers.
  2. Working form: long-term duty, intermittent periodic duty, and short-time duty are three general types. For the valve that often open for a long time, we should select the normally open solenoid valve.
  3. Working frequency: when the working frequency has a high requirement, the structure of solenoid valve should be direct action solenoid valve and the power should be AC.
  4. action reliability: there are some occasions have less requirement on the action times but the reliability, such as fire protection, emergency protection, and etc.

Economy

The economy is another vital standard for solenoid valve selection, but it must base on the safe, applicable and reliable economic. The economy is not only for the price, but the function, quality, installation, maintenance and other costs should be a priority. What’s more, a little solenoid valve takes the slim cost of the whole control system or production line, but it plays a big role in the system.