Nitrogen self operated micro pressure regulating valve nitrogen sealing valve

1、 Product Introduction:

The nitrogen sealing valve of the storage tank nitrogen sealing device consists of several valves such as a nitrogen supply valve, a nitrogen release valve, and a breathing valve. No external energy is required, using the energy of the regulated medium itself as the power source. A pressure stabilizing device that automatically controls the flow rate of the valve medium to maintain a constant pressure behind the valve. The characteristics of this valve are high control accuracy, which can be about twice as high as ordinary direct operated pressure regulating valves. Adjusting the pressure difference ratio (such as 0.8MPa in front of the valve and 0.001MPa behind the valve) is particularly suitable for micro pressure gas control. The pressure setting is implemented on the commander, making it convenient, fast, labor-saving, and time-saving to continuously set during operation. Mainly used for nitrogen sealing systems such as raw material tanks, water tanks, containers, etc.

2、 Working principle of nitrogen supply valve:

(1) When the nitrogen seal valve is closed, the piston of the main valve is in a sealed chamber. When the tank pressure is equal to or greater than the set pressure, the diaphragm is pushed up, and the pilot valve moves upward under the action of the spring, tightly pressing the sealing ring on the pilot valve against the valve seat, closing the inlet of the control gas. At the same time, the pressure in the special valve core chamber increases and approaches the pressure of the nitrogen main pipe. This pressure is transmitted from the special valve core chamber to the main valve core chamber through an internal channel. The piston of the main valve is under the pressure of the nitrogen manifold. Due to the balance of gas pressure on the upper and lower parts of the main valve core, the main valve core tightly closes the valve under its own weight and the action of the spring.

(2) When the nitrogen seal valve is opened, when the pressure in the storage tank is slightly lower than the set pressure, the diaphragm moves downward due to the decrease in induced pressure, pushing the gas guide valve to open. Nitrogen enters the storage tank through the orifice plate and the outlet of the gas guide valve, increasing the pressure inside the storage tank. At the same time, the pressure in the special valve core chamber of the gas guide valve decreases, and nitrogen enters the main valve core chamber through the internal channel from the special valve core chamber. Due to the fact that the piston area of the main valve core is larger than the area of the main valve seat hole, and there is the elastic force of the spring and the weight of the main valve, when the tank pressure is slightly lower than the set point, the pressure in the special valve core chamber and the main valve core chamber decreases very little, and the main valve still remains closed. Nitrogen only enters the tank from the pilot valve.

3、 Nitrogen supply valve

Features:

LKZZYVP-16BNitrogen self operated micro pressure regulating valveNitrogen sealing valveInstant nitrogen valve is an energy-saving pressure regulating valve that does not require external energy and uses the pressure changes of the regulated medium to automatically adjust and stabilize the pressure after the valve to the set value.

The pressure setting of the valve is implemented on the controller, which is convenient and fast. The pressure setting value can also be adjusted freely during operation; High control accuracy, which can be twice as high as the general ZZY type direct operated self operated pressure regulating valve, suitable for occasions with high control accuracy requirements. It is widely used in industrial sectors such as chemical, petroleum, metallurgy, power, and textile industries for automatic regulation of production processes.

Structure and principle:

LKZZYVP-16BNitrogen self operated micro pressure regulating valve nitrogen sealing valveIt is composed of four parts: commander, regulating valve, actuator, and valve connecting pipe. (See Figure 1)

Working principle: The medium enters the valve body in the direction of the arrow shown, and the pressure reduced by the filter pressure reducer is introduced into the controller; The other path passes through the valve core and seat, and the throttled pressure flows towards the back of the valve, and is introduced into the command actuator through the pressure pipe. When the pressure behind the valve is higher than the set pressure, the pressure acts on the effective surface of the controller diaphragm, generating a thrust that drives the controller spool to close, cutting off the pressure introduced into the diaphragm chamber of the main valve actuator, causing the main valve spool to close and the pressure behind the valve to decrease accordingly. When the pressure behind the valve is lower than the set value, the reactive force of the main spring of the controller opens the valve core, and the pressure in front of the valve is introduced into the diaphragm chamber of the main valve actuator to generate thrust, causing the valve core to open and the pressure behind the valve to increase accordingly. Repeat this process to maintain the pressure behind the valve at the set value.

Figure 1 ZZYVP-16B Self operated Micro pressure Regulating Valve with Commander

Main parameters, performance indicators, and materials

1. The main parameters and performance indicators are shown in Table 1

2. The pressure regulation range is shown in Table 2 and Table 2

3. The main component materials are shown in Table 3 and Table 3

Figure 2 Outline drawing

4. The external dimensions are shown in Table 4, Figure 2, and Table 4. Unit: mm

Note: 1) The standard flange connection form PN16 is convex, and the connection size for cast iron flanges is in accordance with GB4216.5-84. For cast steel flanges, it is in accordance with GB9113-2000 and JB/T-94. The valve body flange and flange end face distance can also be manufactured according to user standards, such as ANSI, JIS, DIN, etc.

2) Take over and configure according to user needs

5. The product weight is shown in Table 5. Unit: Kg

4、 Nitrogen release valve

Features:

ZZVP and ZZCP type self operated micro pressure and differential pressure regulating valves are energy-saving regulating valves that rely on the pressure changes of the regulated medium to automatically adjust or maintain a constant pressure difference.

Main technical parameters and performance indicators:Table 1 Kv values and performance indicators

Table 2 Micro and Differential Pressure Adjustment Range

Figure 2 Outline drawing

Table 3 Dimensions and Weight Unit: mm

Installation, maintenance, and debugging:

1. Installation (see Figure 2)

• Check whether the parts of the whole machine are damaged or loose. For media that are harmful to human health, strength, sealing, leakage, and accuracy tests must be conducted.

• Before installation, clean the pipeline (otherwise, due to welding slag and other pipeline debris, the sealing surface of the valve core may be damaged, causing the valve to not work properly). There should be sufficient straight pipe sections at the valve inlet, and a filter should be installed. The flange connection between the valve body and the pipeline should pay attention to coaxiality.

• The installation site should consider the safety of personnel and equipment, and be conducive to disassembly, assembly, and maintenance even during operation.

• The valve should be installed upright and vertically on a horizontal pipeline, and the pressure pipe must be installed on the pipeline behind the valve at least six times the nominal diameter from the valve outlet. In situations where the valve has a large self weight and vibration, a support frame should be used to avoid horizontal installation as much as possible.

• The direction of medium flow should be consistent with the arrow on the valve body. Due to the fact that micro pressure valves are precision instruments, the diaphragm directly bears the pressure of the medium. If the valve is reversed or there is recoil pressure in the pipeline, the diaphragm will be damaged due to excessive pressure, and the valve will not work. Valves should be used in environments with temperatures ranging from -25 ℃ to+55 ℃.

• In order to ensure continuous production even when the self-control system malfunctions or valves are under maintenance, a bypass valve should be installed.

  
  

Precautions for selecting regulating valves:

1. It is unreasonable to select the regulating valve directly according to the pipe diameter of the connecting pipe. The quality of valve regulation is not related to the flow rate or pipe diameter of the connecting pipe. The quality of valve regulation is only related to the resistance and flow rate of water. Once the system equipment is determined, theoretically there is only one ideal diameter of valve suitable for the system, and there will not be multiple choices.

2. The diameter of the regulating valve cannot be too small. Choosing a valve with a diameter that is too small can increase the system's resistance, and even result in the system being unable to meet the set capacity requirements when the valve diameter is 100% open, leading to serious consequences. On the other hand, the valve will need to provide a large pressure difference through the system to maintain sufficient flow, which will increase the load on the pump and make the valve vulnerable to damage, greatly affecting its lifespan.