Pressure control nitrogen seal valve for acetic acid storage tank

1、 Product Description:

ZZYVP-16BPressure control of acetic acid storage tankNitrogen sealing valveWithout the need for external energy, automatic regulation is achieved by utilizing the pressure changes of the regulated medium itself, ensuring a constant pressure behind the valve. The entire machine has sensitive action, minimal pressure fluctuations, and energy savings.

The nitrogen sealing valve, also known as the nitrogen supply valve, adopts a method of separating the power source and signal points for detection, and an adjustable flow device is added to greatly improve the adjustment accuracy of the entire valve, with a pressure reduction ratio of up to 2000:1. Widely used in various automatic control scenarios for gas pressure reduction and stabilization, it is particularly suitable as a nitrogen supply valve for nitrogen sealing, with characteristics such as small continuous nitrogen supply pressure fluctuations and sensitive response.

two、The properties of acetic acid series compounds:

The acetic acid series compounds mainly include acetic acid, acetic anhydride, ethyl acetate, etc., which have characteristics such as flammability, explosiveness, and toxicity. They may pose a threat to human health and the environment, so special care should be taken during storage and transportation.

IIIStorage tankMaterial storage specifications:

1. Storage facilities: Facilities for storing acetic acid series compounds should comply with relevant safety standards and have functions such as fire prevention, explosion prevention, and leak prevention. Ventilation equipment should be installed in the facility to maintain air circulation.

2. Storage container: Containers that meet national standards should be selected for storage to ensure good sealing and corrosion resistance. Regularly inspect and maintain containers to ensure they are in good condition.

3. Storage environment: Acetic acid series compounds should be stored in a cool, dry, well ventilated place, away from sources of fire, heat, and direct sunlight. The temperature of the storage area should be controlled within an appropriate range to avoid excessive or insufficient temperature affecting the compound.

4. Storage management: Establish a strict storage management system to keep detailed records of the inbound, outbound, and inventory of acetic acid series compounds, ensuring consistency between accounts and goods. Regularly conduct security checks on storage facilities to promptly identify and eliminate security risks.

4、 Main structure of valve:

5、 Characteristics:

Add adjustable flow device for easy and convenient debugging.

Design pressure compensation device for valve internals to eliminate the impact of pressure fluctuations on setting accuracy and achieve more stable regulation.

The whole machine adopts a filler free design, which operates quickly.

The segmented range of pressure setting points is fine and staggered, making it easy to select.

The pressure setting is convenient, and it can be continuously set without interference during operation, without maintenance.

Equipped with pressure pipes and fittings, installation is simpler and more reliable.

This valve does not require external energy and can work in situations without electricity or gas, which is both convenient and energy-saving.

The large and sensitive detection membrane ensures the pressure accuracy of the control point.

The signal detection actuator is separated from the power actuator, allowing the pressure reduction ratio of the entire pressure regulating valve to reach 2000:1.

6、 Nitrogen sealing system scheme and installation method of nitrogen supply valve:

A general nitrogen sealing system consists of three main components: a nitrogen supply valve, a nitrogen release valve, and a breathing valve.

7、 Working principle of nitrogen sealing system:

ZZYVP-16BPressure control nitrogen seal valve for acetic acid storage tankWhen the discharge valve of the storage tank is opened and the material is discharged, the liquid level drops, the volume of the gas phase increases, the nitrogen pressure inside the tank decreases, and the nitrogen supply valve opens. Nitrogen is injected into the storage tank, and the nitrogen pressure inside the tank increases. When the pressure inside the tank rises to the set value of the nitrogen supply valve, the nitrogen supply valve automatically closes.

When the inlet valve of the storage tank is opened and the material is fed, the liquid level drops, the volume of the gas phase decreases, and the pressure inside the tank increases. When it is higher than the set pressure of the nitrogen release valve, the nitrogen release valve opens and releases nitrogen gas to the outside. The nitrogen pressure inside the tank decreases, and when it drops to the set pressure of the nitrogen release valve, the nitrogen release valve automatically closes.

Valve selection instructions:

The general nitrogen supply pressure is around 300-800KPa, the nitrogen seal setting pressure is 1KPa, the nitrogen release pressure is 2KPa, the exhalation pressure of the breathing valve is 3KPa, and the inhalation pressure is -300Pa.

The top breathing valve of the tank only serves a safety purpose and does not work under normal circumstances when the main valve fails, causing the pressure inside the tank to be too high or too low.

The nitrogen release valve is installed on the top of the tank, and its diameter is generally similar to that of the inlet valve, but the operating parameters are different, which needs to be determined through selection calculation.

The general nitrogen supply valve uses ZZVVP-16B type commander self operated pressure regulating valve, the nitrogen release valve uses ZZVP-16K self operated micro pressure regulating valve, and the breathing valve uses flame retardant type.

8、 Installation precautions:

The ZZYVP-16B nitrogen supply valve operates the actuator using the pressure of the medium itself, filling the actuator with the medium. Therefore, a reasonable installation method will improve the adjustment accuracy of the set point and increase the service life of the valve.

The location of the pressure tapping point during installation should be at an appropriate distance from the pressure regulating valve, greater than 6-10 times the diameter of the pipeline.

Suggest installing a bypass for regular maintenance.

The commander and main valve can be installed separately.

9、 Installation, maintenance, and debugging:

1. Installation

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 of the controller directly bears the pressure of the medium. If the valve is reversed or there is recoil pressure in the pipeline, the diaphragm of the controller 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 automatic control system fails or valves are repaired, a bypass valve should be installed (see Figure 3).

2. Maintenance:

Cleaning valves: For cleaning general media, simply rinse with water. However, when cleaning media that are harmful to health, it is necessary to first understand their properties and select appropriate cleaning methods.

Disassembly of valves: Remove rust from the exposed surfaces of rusted parts first, but before rust removal, protect the machined surfaces of precision parts such as valve seats, valve cores, valve stems, and push rods. Special tools should be used when disassembling and assembling valve seats.

Valve core and valve seat: There are small rust spots and wear on the second sealing surface, which can be repaired by mechanical processing. If the damage is severe, it must be replaced. But regardless of whether the hard sealing surface is repaired or replaced, it must be ground.

Valve stem: Surface damage, must be replaced.

Compression spring: If there are defects such as cracks that affect strength, it must be replaced.

Vulnerable parts: packing, sealing gasket, and O-ring, all replaced with new ones during each maintenance. The membrane must be checked for signs of possible cracking, aging, and corrosion in the future. Based on the inspection results, it is decided whether to replace it. However, the membrane is generally used for a maximum of 2-3 years.

Valve assembly should pay attention to alignment, bolts should be tightened diagonally, and lubricating oil should be added to the sliding parts. After assembly, the product should be debugged according to the factory testing items and methods, and during this period, the packing clamping force and valve core closing position can be adjusted more accurately.

3. Debugging:

The required pressure value is adjusted by operating the adjusting nut on the top of the commander, opening the dust cover on the top, and adjusting the adjusting nut with a wrench. Clockwise rotation increases pressure, while counterclockwise rotation decreases pressure. The pressure gauge installed behind the pressure regulating valve allows personnel to observe the adjusted pressure setpoint.