Introduce the causes and preventive measures of NORGREN solenoid valve faults separately

Therefore, it can overcome the disadvantage of force balance of conventional locators. But when used in emergency parking situations, such as emergency shut-off valves, emergency vent valves, etc. These valves are required to remain stationary in a certain position, and the bottom valve only needs to operate reliably in emergency situations. Staying in a certain position for a long time can easily cause the electrical converter to lose control and result in small signals not functioning

The device of NORGREN solenoid valve is different from other valves. It requires a lot of preparation work before installation, such as cleaning the pipeline, inspecting the valve, etc. Below is a specific introduction to the device skills and operation process of pneumatic control valve, as follows:

1. Follow the guidance and precautions for NORGREN solenoid valve installation;

2. NORGREN solenoid valve device operation manual: Read the instruction manual between the device valves first. The tutorial manual introduces the product and the safety precautions and preventive measures that should be taken before and during installation. Following the guidelines in the manual can help ensure the simplicity and success of the device;

3. Admitting pipeline cleaning: Foreign objects in the pipeline may damage the sealing surface of the valve or even prevent the movement of the valve core, ball, or butterfly plate, causing the valve to fail to close correctly;

4. Check the NORGREN solenoid valve: Before installation, check and remove all transport stops, protective plugs, or covers on the surface of the gasket, and check the inside of the valve body to ensure that there are no foreign objects;

5. Choose outstanding pipe fittings for practice: The vast majority of pneumatic control valves can be installed in any orientation, but the general method is to place the actuator straight and sit on the upper part of the valve. If a horizontal device for the actuator is necessary, consider adding a rated straight support to the actuator. It should be ensured that the valve body is installed in such a way that the fluid flow direction is consistent with the direction indicated by the flow arrow or the instruction manual;

6. Ensure that there is sufficient space above and below the valve for easy disassembly of the actuator or valve core during inspection and protection. The spatial spacing can generally be found on the external dimension drawing recognized by the valve manufacturer. For valve bodies with flange connections, ensure that the flange faces are aligned to ensure even contact between the gasket surfaces. After aligning the flange, gently tighten the bolts and finally tighten them in a staggered manner.

Adhere to shorter connection intervals and minimize the number of pipe fittings and elbows to reduce system time lag. If the interval needs to be very long, a locator or booster can be used on the pneumatic control valve.

(1) Due to the use of mechanical force balance principle, there are many movable parts, which are easily affected by temperature and vibration, causing fluctuations in the regulating valve;

(2) Using nozzle baffle technology, due to the small nozzle hole, it is easy to be blocked by dust or clean air source without diaphragm valve, which makes the locator unable to work properly;

(3) Using the principle of force balance, the elastic coefficient of the spring changes in harsh environments, causing nonlinearity in the regulating valve and resulting in a decrease in control quality.

The intelligent locator is powered by a microprocessor and its working principle is completely different from that of a regular locator. The comparison between the given value and the actual value is purely an electric signal, no longer a force balance.

In addition, the position sensing potentiometer used for valves is prone to changes in resistance value due to its operation on site, resulting in dangerous situations where small signals do not operate and large signals are fully open. Therefore, in order to ensure the reliability and usability of intelligent locators, they must be frequently tested.

(1) In general, valves are not subjected to strength tests, but after repair, the valve body and valve cover, or those that have been corroded or damaged, should undergo strength tests. For safety valves, their constant pressure, reseating pressure, and other tests should comply with the instructions and relevant regulations of the sight glass cup valve.

(2) The installation of valves should undergo strength and sealing tests. 20% of low-pressure valves shall be randomly inspected, and if they are found to be unqualified, they shall be inspected accordingly; Inspection of medium and high pressure valves.

(3) During the experiment, the valve should be installed in a direction that is easy to inspect.

(4) For valves with welded connections, if pressure testing with blind plates fails, cone sealing or O-ring sealing can be used for pressure testing.

(5) During hydraulic testing, try to eliminate valve air as much as possible.

(6) During the experiment, the pressure on the sanitary valve should gradually increase, and rapid or sudden pressure increase is not allowed.

(7) The duration of strength test and sealing test is generally 2-3 minutes, and important and special valves should last for 5 minutes. The testing time for small-diameter valves can be correspondingly shorter, while the testing time for large-diameter valves can be correspondingly longer. If there are any questions during the experiment, the test time can be extended.

Although there have been some introductions before, it is not enough to comprehensively summarize and synthesize this product. Therefore, for us, especially learners, it is still necessary to continuously learn and understand the relevant knowledge of this product. We cannot relax. Therefore, let's inherit and introduce it below, so that everyone can possibly know more about the relevant knowledge of pneumatic control valves.

1. Run

(1) Before using NORGREN solenoid valves, a system calibration should be conducted first.

(2) During the operation of NORGREN solenoid valve, all bypass valves should be closed and the regulating valve should be within the normal working range. It is strictly prohibited to adjust the position of the entire valve stem and compression spring. If there is any abnormality, immediate punishment should be imposed.

2. Regular inspection

(1) It is important to check whether there are any signs of looseness or leakage in the air source pressure, fasteners, and instruments of the NORGREN solenoid valve. If there are any, they should be dealt with in a timely manner.

(2) All connecting components should be inspected for tightness, friction, scratches, and deformation.

(3) What is the protective environment of the instrument route and is the sealing environment of the sealed area.

(4) Is the valve stem running smoothly and is there any sign of rust on the valve.

3. Rain proof inspection

The first thing to check is whether the instrument wiring port is damp, there may be signs of water ingress.

4. Maintenance and upkeep: (1) Clean and lubricate each component to prolong the service life of the pneumatic control valve.

(2) Pneumatic control valves should be regularly discharged and lubricated, and the oil storage in the oil injector should be sufficient. If the amount is insufficient, it should be replenished in a timely manner.