In industrial enterprises, especially urban waterworks, in the process of production and water supply, the use of a large number of ordinary gate valves, butterfly valves, liquid control butterfly valves, etc., to control the production of tap water, is a major equipment for water supply enterprises. Among the various types of valves used, there are a large number of gate valves. This article will discuss how to adjust the electric device of the electric valve. The electric gate valve is composed of a valve electric device and a gate valve to form a electric gate valve for controlling the opening and closing of the gate valve. It can be operated on site or remotely. The valve electric device is composed of an electric motor, a speed reducer, a torque limiting mechanism, a stroke control mechanism, a manual electric conversion mechanism, an opening indicating mechanism and an electric controller. If the electric device of the electric gate valve is improperly adjusted, it will shorten the service life of the gate valve; the heavy one will cause the cast iron shell of the valve to break, control the motor to burn out and flood the pump room and other serious accidents. Therefore, in order to ensure safe and uninterrupted water supply, the electric device of the electric gate valve must be carefully adjusted to ensure the smooth opening and closing of the electric gate valve. The following describes two adjustment methods for the electric gate valve: 1. Adjustment of the torque limiting mechanism The electric gate valve is used in different places because the water pressure difference or the air pressure difference at both ends of the shutter is different (when the gate valve is closed), the torque limiting mechanism can be appropriately adjusted. When the water pressure or air pressure difference is low in the direction of the end of the electric gate valve, the torque limiting mechanism should be adjusted to a lower torque. Use the HZ series (see Figure 1), Z series (see Figure 2) or ZB series. (See Figure 3.) When the valve is electrically operated, it is only necessary to adjust the distance between the adjustment plate and the trigger plate of the torque limiting mechanism (see the adjustment instructions for details). The scale is marked with a scale, and the larger the scale value, the larger the torque value. When the water pressure difference or the air pressure difference between the two ends of the electric valve shutter is closed, the adjusted torque value is required to be larger, and vice versa. The above series are adjusted in the same way. When adjusting the ZD series valve electric device (see Figure 4), remove the side cover of the box, adjust the torque limiting mechanism, loosen the set screw in the adjusting nut, loosen the adjusting nut, loosen the button spring, and put To the loosest position, then tighten the set screws in the adjusting nut to secure the adjusting nut. Note that the top end of the set screw must fall in the shaft groove. If the top end is not aligned with the shaft groove, just turn the adjusting nut a little to the direction of the compression spring to align it with the shaft groove setting screw. Then install the side cover and adjust the opening valve. If the torque limiting mechanism moves, the spring is too loose to adjust until it stops. In this way, the torque limiting mechanism can be operated at a lower torque, and the torque limiting mechanism can be reliably operated when the electric gate valve fails due to the failure of the stroke control mechanism or other reasons, and the motor power supply is cut off to protect the valve from damage. The electric gate valve used in some places does not have to be adjusted too tightly, and it is better to adjust it to a half turn (or one turn) after manual closing (or no leakage or gas). Figure 1 HZ series torque limiting mechanism Figure 2 Z series torque limiting mechanism Figure 3 ZB series torque limiting mechanism Figure 4 ZD series torque limiting mechanism When the electric gate valve is installed in a place where the outlet water pressure difference (or air pressure difference) is large, the torque limiting mechanism should be adjusted to the appropriate opening and closing torque. For example, if the outlet valve is installed in the pump house, the outlet pressure is larger when the gate valve is not opened after the pump is started. At this time, the larger the diameter of the outlet valve, the greater the torque used to open the gate valve. In particular, when there is no pressure in the pipe, the damper of the gate valve is subjected to the maximum unidirectional pressure. At this time, the nut compression spring is adjusted to adjust to the normal opening and closing of the gate valve, and the torque limiting mechanism does not operate. The electric gate valve used in the pump house must be adjusted to the fully open and fully closed position during adjustment. Otherwise, it is easy to damage the sealing surface of the gate valve and cause water leakage. Because the electric gate valve installed at the place is close to the water outlet of the pump, the water flow rate is high and unstable. At this time, if the gate valve is not fully opened, some of the rams are moved forward and backward due to the impact of the water flow, causing the sealing surface of the ram to wear and form a concave. Tank leakage affects the service life of the valve. In addition, the electric gate valve should be avoided as much as possible to adjust the flow, otherwise it will easily damage the sealing surface of the gate valve. In addition, in recent years, the frequency conversion speed regulation technology is developing rapidly, and the water pump flow regulation should adopt the frequency conversion speed regulation technology to achieve energy saving and consumption reduction to improve the pump working efficiency. 2 “On, Off” position adjustment of the electric gate valve Adjust the opening and closing of the electric gate valve. According to the adjustment requirements of each manufacturer, the valve should be manually closed to the "fully closed" position or the "fully open" position. If it takes a lot of time to manually close the large-diameter gate valve according to this requirement, it is still very laborious. Here is a new adjustment method: If you know the stem distance of the gate valve, it is very convenient to adjust when adjusting the electric gate valve. At present, the diameter of the valve stem of the gate valve of domestically produced valve in DN400-DN600 is generally 8mm, and the pitch of the valve stem of the gate valve of DN600 or above is generally 10mm. If possible, ask the gate valve manufacturer for the stem distance. When adjusting the valve electric device, if the position of the gate valve is known in advance, if it is known that the gate valve is in the fully closed position, adjust the "fully closed" position first. First, manually turn the gate valve in the direction of opening, such as the valve stem rotating half a circle or one turn. Then send the power and press the "On" button. Check the steering. If the valve stem is pressed, the steering of the valve stem is the same as the steering of the valve stem when the valve is manually opened, indicating that the phase sequence of the motor is in the same direction as the electrical controller of the valve. At this time, the stroke control of the gate valve can be adjusted first. The mechanism is adjusted to the fully closed position, and after the fully closed position is adjusted, the fully open position of the gate valve can be adjusted. At this time, when the gate valve is opened, the number of turns of the valve gate of the number of gate valves is known to be in the "full open" position. If it is the electric gate valve of DN500, the valve stem pitch is 8mm, the valve stem turns 8mm, and the gate valve plate should be moved upwards 500mm when fully open, so the valve stem needs to rotate 500/8=62.5 turns when fully open. At this point, press the number of valve opening buttons to the 63-turn valve to the "full open" position, adjust the stroke controller of the valve electric device, and make the micro-switch of the "full open" position move. After that, the electric gate valve can be closed, the inspection is turned on once, and the adjustment is completed. If the power gate valve is in the open position before adjustment, the position of the opening should be adjusted first, as described above. 3 Precautions after adjustment One year after the use of the electric gate valve, check whether the set screws in the adjusting nut of the torque limiting mechanism are loose or come off. In particular, ZD series valve electric devices (see Figure 4), some of the electric gate valves in use occur when the bottom of the gate valve is broken by the valve plate or the upper ribs of the upper fixed electric device are cracked. Why is there a torque limiting mechanism that does not operate when the torque is over? The power is not cut off. The reason is that the set screw of the adjusting nut in the torque limiting mechanism is loosened and the adjusting nut is tightened for a long time until it is crushed. The spring makes the torque limiting mechanism lose its function, does not protect, and causes the electric gate valve to be damaged. Therefore, it is necessary to check whether the set screw is detached once a year. If the tightening screw is loose, it should be tightened in time, and the cause of the detachment should be ascertained. The manual-electric conversion handle requires flexible mechanical mechanism and can be easily moved. When the manual is pulled, the power supply must be cut off to avoid an accident when it fails. Gate valves that are rarely opened and closed for a long time should be periodically switched to ensure normal operation during use. (It is recommended to rotate once every three months).

Product name         Zinc Phosphate

CAS No              7779-90-0

EC No                231-944-3

Chemical formula      Zn3(PO4)2.2H2O

Appearance           White Powder

Storage               Keep the product in a tightly closed container ,Isolate form any source of heat or ignition and moisture

Packing unit          25kg Poly Propylene bag & 500kg Poly Propylene bag,

Any size customers want.

Application           Material for anti-corrosion paint used in container,

Ship and steel structures .Electronic materials

Goods characteristics   White Powder.

Soluble in acid or alkali solution ,insoluble in water or alcohol.

CHEMICAL ANALYSIS

★ Product grade: Zn 50.5-52%

50.5% Zinc Content Zinc Phosphate

50.5% Zinc Phosphate, Anticorrosive Paint 50.5% Zinc Phosphate

shijiazhuang city xinsheng chemical co.,ltd , http://www.xsphos.com