At YeeValve, we specialize in manufacturing high-quality N2 blanketing valves, designed to ensure the safety and integrity of storage tanks. Our valves are engineered to maintain a consistent nitrogen atmosphere, preventing contamination and minimizing the risk of oxidation and combustion.
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The N2 blanketing valve is designed to maintain constant gas pressure in the vapor space of storage tanks. Itis capable of regulating the desired pressure within specific limits when liquid runs out or when a vacuum occurs due to a temperature decrease. Additionally, it serves to prevent air and humidity from entering the storage vessel, thereby preserving products and safeguarding against fire. The controller also plays a critical role in protecting the tank from explosions by restricting sparks and preventing fluid outflow through evaporation.
| Nominal Diameter DN(mm) | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 | 250 | 300 | |
| Rated Flow Characteristic Kv | Single-Seated | 7 | 11 | 20 | 30 | 48 | 75 | 120 | 190 | 300 | 480 | 760 | – | – |
| Cage Type | 7 | 11 | 20 | 30 | 48 | 75 | 120 | 190 | 300 | 480 | 760 | – | – | |
| Double-Seated | – | – | 22 | 33 | 53 | 83 | 132 | 209 | 330 | 528 | 836 | 1210 | 1925 | |
| Rated Travel (mm) | 8 | 10 | 14 | 20 | 25 | 40 | 50 | 60 | 70 | |||||
| Adjusting Pressure Range (kPa) | 15~50,40~80,60~100,80~140,120~180,160~220,200~260,240~300,280~350,330~400,380~450, | |||||||||||||
| 430~500 | ||||||||||||||
| Nominal Diameter DN(mm) |
20, 25 | ||||||||||||
| Seat Diameter(mm) | 6 | 7 | 8 | 10 | 12 | 15 | |||||||
| Rated Flow Characteristic Kv |
0.01 | 0.02 | 0.048 | 0.06 | 0.08 | 0.12 | 0.2 | 0.32 | 0.5 | 0.8 | 1.8 | 2.8 | 4.4 |
| Rated Travel (mm) | 5 | ||||||||||||
| Body Material | WCB, WCC, WC6, WC9, LCB | |||||||||||||||||||||||||
| Trim | Material | 304/316 | 304/316 | 304/316 | 304/316 | |||||||||||||||||||||
| Treatment | RTFE | ST | SS | |||||||||||||||||||||||
| Seat | Material | 304/316 | 304/316 | 304/316 | 304/316 | |||||||||||||||||||||
| Treatment | RTFE | -- | ST | SS | ||||||||||||||||||||||
| Allowed Leakage | Class | Ⅳ/Ⅴ/Ⅵ | Ⅳ | Ⅳ/Ⅴ | Ⅳ/Ⅴ | |||||||||||||||||||||
| Standard | GB/T4213，FCI70.2 | |||||||||||||||||||||||||
| Service Temperature (℃) |
WCB, WCC | -5~+160 | -5~+230 | -5~+425 | -5~+425 | |||||||||||||||||||||
| WC6, WC9 | -5~+160 | -5~+230 | -5~+538 | -5~+538 | ||||||||||||||||||||||
| LCB | -45~+160 | -45~+230 | -45~+350 | -45~+350 | ||||||||||||||||||||||
| Body Material | CF3, CF8, CF3M, CF8M | |||||||||||||||||||||||||
| Trim | Material | 304/316 | 304/316 | 304/316 | 304/316 | |||||||||||||||||||||
| Treatment | RTFE | ST | SS | |||||||||||||||||||||||
| Seat | Material | 304/316 | 304/316 | 304/316 | 304/316 | |||||||||||||||||||||
| Treatment | RTFE | -- | ST | SS | ||||||||||||||||||||||
| Allowed Leakage | Class | Ⅳ/Ⅴ/Ⅵ | Ⅳ | Ⅳ/Ⅴ | Ⅳ/Ⅴ | |||||||||||||||||||||
| Standard | GB/T4213, FCI70.2 | |||||||||||||||||||||||||
| Service Temperature(℃) | -45~+160 | -196~538 | -196~538 | -196~538 | ||||||||||||||||||||||
The N2 blanketing system consists of an N2 supply device and an N2 relief device. The N2 supply device includes a controller and a main valve, while the N2 relief device typically consists of an internal feedback micro-pressure regulating valve. The N2 blanketing pressure is generally set between 50 to 400 mmH2O and is precisely controlled by the N2 blanketing device.
When the tank's inlet valve opens to filling material, the liquid level rises, reducing the gas volume and increasing the pressure. When the internal pressure exceeds the set value of the N2 release unit, the release unit opens to discharge nitrogen, lowering the tank's pressure. Once the pressure falls below the set point, the release unit closes automatically.
When the tank's outlet valve opens to discharge material, the liquid level drops, increasing the gas volume and lowering the pressure. The N2 supply device then opens to inject nitrogen quickly, raising the tank's pressure. Once the pressure reaches the set point, the supply device closes automatically.
The breather valve on the top of the tank acts as a safety feature. If the N2 blanketing system fails or cannot meet the flow requirements, the breather valve opens to release excess nitrogen or draw in air, protecting the tank. Under normal conditions, the breather valve remains closed.
i. The typical nitrogen supply pressure ranges between 0.1 to 1 MPa. The more stable the pressure, the higher the adjustment accuracy of the N2 supply valve, resulting in a more stable N2 blanketing pressure.
ii. The breather valve on the tank top serves only a safety role. It activates when the main valve fails, causing excessive pressure inside the tank. It does not operate under normal conditions.
iii. The N2 release valve is installed on the tank top, usually with the same diameter as the inlet valve.
iv. The pressure set point of the N2 release unit is slightly higher than that of the N2 supply valve. The breather valve's pressure set point is slightly higher than that of the N2 release unit to prevent frequent operation, which wastes nitrogen and affects equipment lifespan.
v. Provide the chemical composition of the liquid inside the N2-blanketed tank to select the appropriate valve materials.
vi. If the end-user's conditions differ from the selection manual, contact YeeValve engineers for a customized optimal solution.
Upon receiving the valve on-site, avoid pulling, pressing, or lifting the valve's pressure guide tube during handling and installation to prevent performance damage. Check for any exterior damage, loose fasteners, and contaminants in the flow path. Verify the product model, position number, and specifications.
Install the pressure take-off point at a suitable distance from the pressure regulating valve, at least six times the pipe diameter, and it should be on the top or side of the pipe to prevent debris from entering the actuator. Install the controller-operated self-operated pressure regulating valve vertically on a horizontal pipe. See the blew diagram for the connection of the pressure take-off joint and the pipe.
Ensure adequate space around the valve for maintenance and operation, and install bypass valves and appropriate pressure gauges upstream and downstream.
Clean the pipeline before installing the pressure regulating valve, as debris can damage the valve's sealing surface or obstruct the movement of the valve core and actuator, preventing proper operation. Confirm the removal of pipeline dirt, metal shavings, welding slag, and other debris. Check the pipe flanges to ensure a smooth gasket surface. For threaded connections, apply a high-grade sealant to the male threads only, as excess sealant on the female threads can enter the valve body, causing the valve core to stick or dirt to accumulate.
Filter the fluid before use to maximize the performance of the pressure regulating valve.
Close the cut-off valve on the pressure guide tube before use to protect the actuator and the entire valve. Open it during normal operation.
Ensure the direction of the arrow on the valve body matches the installation direction of the pipe.
After installation, perform a leak test on all joints using soapy water or a similar method.
| Size DN | 15 | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| L | 130 | 150 | 160 | 180 | 200 | 230 | 290 | 310 | 350 | 400 | 480 | 600 |
| H | 690 | 690 | 690 | 705 | 705 | 760 | 800 | 800 | 840 | 880 | 980 | 1050 |
| A | φ308, φ394 | |||||||||||
| L1 | 233 | 233 | 233 | 332 | 332 | 373 | 572 | 572 | 673 | 980 | 980 | 1200 |
| P≥ | 135 | 135 | 170 | 220 | 220 | 235 | 245 | 325 | 425 | 550 | 660 | 900 |
| H1 | 330 | |||||||||||
| GW(kg) | 18 | 18 | 18 | 25 | 27 | 42 | 65 | 80 | 108 | 182 | 260 | 305 |
| Size DN | 15 | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| L | 130 | 150 | 160 | 180 | 200 | 230 | 290 | 310 | 350 | 400 | 480 | 600 |
| A | φ280, φ308, φ394, φ498 | |||||||||||
| H₁ | 42 | 42 | 48 | 56 | 64 | 76 | 85 | 100 | 110 | 126 | 160 | 202 |
| H | 450 | 450 | 450 | 470 | 485 | 490 | 530 | 550 | 560 | 650 | 660 | 900 |
| GW(KG) | 12 | 12 | 13 | 14 | 16 | 19 | 28 | 45 | 78 | 130 | 200 | 265 |
| NO. | Problem | Possible Cause | Corrective Action Steps |
|---|---|---|---|
| 1 | Downstream pressure does not drop, remains above the set value | 1. Diaphragm of the controller is damaged 2. Spring stiffness of the controller is too high 3. Throttle valve opening is too small |
1. Replace the diaphragm: Inspect the controller diaphragm for damage and replace it if necessary. 2. Replace the spring: Check the spring in the controller. If the spring stiffness is too high, replace it with a spring of appropriate stiffness. 3. Adjust the throttle valve opening: Ensure that the throttle valve is adequately opened. Adjust the opening as required to allow for proper pressure regulation. |
| 2 | Downstream pressure does not rise, remains below the set value | 1. Spring stiffness of the controller is too low 2. Throttle valve opening is too large 3. Main diaphragm is damaged |
1. Replace the spring: Inspect the spring in the controller. If the spring stiffness is too low, replace it with a spring of appropriate stiffness. 2. Adjust the throttle valve opening: Ensure that the throttle valve is not excessively open. Adjust the opening to allow for proper pressure regulation. 3. Replace the diaphragm: Inspect the main diaphragm for damage and replace it if necessary. |
| 3 | Large leakage when valve is fully closed | 1. Valve stem or push rod is stuck 2. Foreign matter or wear on valve core 3. Valve seat threads are corroded |
1. Check alignment and reinstall: Inspect the valve stem and push rod for proper alignment. If they are stuck, realign and reinstall them correctly. 2. Remove foreign matter or replace valve core: Check for any foreign matter on the valve core or signs of wear. Clean any debris or replace the valve core if it is worn out. 3. Replace valve seat: Inspect the valve seat threads for corrosion. If corroded, replace the valve seat. |
| 4 | Pressure is applied to the diaphragm chamber, but no action occurs | 1. Controller malfunction 2. Valve stem is bent or broken 3. Pipeline blockage |
1. Inspect the controller: Check the controller for any malfunctions. Repair or replace the controller if it is faulty. 2. Replace the valve stem: Inspect the valve stem for bends or breaks. Replace the valve stem if it is damaged. 3. Clean the pipeline: Check the pipeline for any blockages. Clean the pipeline thoroughly to ensure there is no obstruction. |
a. Before operation, ensure the design pressure, temperature, and flow rate upstream of the valve match actual working conditions.
b. During initial startup and post-maintenance startup, confirm that the valve core of the self-operated micro-pressure regulating valve is in the initial fully closed position. If there is a bypass, first close the bypass manual valve, then open the downstream manual cut-off valve, and finally, slowly open the upstream manual cut-off valve.
a. The product is adjusted according to user requirements at the factory and is ready for use upon arrival. However, if process parameters change and the upstream pressure does not meet usage requirements, manually adjust the set point to change the upstream pressure. Adjust the nut to change the spring preload and modify the upstream pressure set value. Monitor the upstream pressure gauge until the upstream pressure meets the requirements, then put it into normal operation.
b. During normal operation, only observe the upstream pressure gauge to ensure the pressure is stable and meets the requirements.
| NO. | Problem | Possible Cause | Corrective Action Steps |
|---|---|---|---|
| 1 | Upstream pressure does not rise, remains below the set value | 1. Spring stiffness is too low 2. Valve core is blocked by foreign matter 3. Valve stem is stuck 4. Valve core or seat is damaged, causing excessive leakage 5. Valve port diameter is too large |
1. Replace the spring: Inspect the spring in the controller. If the spring stiffness is too low, replace it with a spring of appropriate stiffness. 2. Reassemble: Disassemble the valve, check for blockages or foreign matter, clean if necessary, and reassemble. 3. Readjust: Check the valve stem for proper alignment and operation. If it is stuck, adjust or realign it as needed. 4. Regrind or replace: Inspect the valve core and seat for damage. If they are damaged and causing leakage, regrind or replace them. 5. Replace with a smaller diameter valve: If the valve port diameter is too large, replace it with a valve that has a smaller port diameter to ensure proper pressure control. |
| 2 | Upstream pressure does not drop, remains above the set value | 1. Spring stiffness is too high 2. Valve port diameter is too small 3. Valve core, stem, or push rod is stuck |
1. Replace the spring: Inspect the spring in the controller. If the spring stiffness is too high, replace it with a spring of appropriate stiffness. 2. Replace with a larger diameter valve: If the valve port diameter is too small, replace it with a valve that has a larger port diameter to ensure proper pressure control. 3. Eliminate cause of blockage, readjust: Inspect the valve core, stem, and push rod for any blockages or sticking. Remove any foreign matter, ensure all components move freely, and readjust as necessary. |
| 3 | Upstream pressure fluctuates too frequently | 1. Valve port diameter is too large 2. Actuator chamber capacity is too small |
1. Select an appropriate valve port diameter: If the valve port diameter is too large, replace the valve with one that has a more suitable port diameter to ensure stable pressure control. 2. Add a damper to the pressure guide tube: Install a damper in the pressure guide tube to increase the damping effect and stabilize the pressure fluctuations. |
Features and Benefits of Purchasing Breather Valves from YeeValve
Our Pressure/Vacuum Relief Valves offer high flow rates from a compact design, maximizing efficiency.
A broad range of pressure and vacuum settings ensures optimal tank protection while minimizing gas losses.
YeeValve's breather valves are designed and manufactured to meet API Standard 2000:2014 and EN ISO 28300:2016, which ensures high-quality and reliability for the end-users.
Our valves with superior sealing technology meet the strict requirements of emission control regulations.
YeeValve exceed the seat leakage standards set by API Std 2000:2014 and EN ISO 28300:2016, with no measurable leakage below 90% of set pressures and less than 1 SCFH (0.03 m3/h) at 90% of the set pressure.
Our breather valve with Low leakage rates significantly cut down on evaporation losses, preserving more of your product.
With economic benefits arise from minimized product loss from YeeValve breather valves, which enhances overall operational efficiency.
We do not only produce standard valves but also provide custom services, such as different connection requests from engineering companies to meet their specific installation needs.
We provide a valve sizing service to ensure optimum valve performance and a cost-effective technical specification to meet our customers' unique needs.
YeeValve offers professional technical support to assist with any inquiries or issues, ensuring smooth operation and maintenance.
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