VN-A-PCPF
Pressure/Vacuum Relief Valve, Pilot-operated diaphragm valve
Features
Function and Description
Combined Pressure and Vacuum Relief Valve
The PROTEGO® Type VN-A-PCPF pilot-controlled diaphragm Membrane A diaphragm is a thin layer of material, which has a large surface area. valve is a newly developed valve for pressure and vacuum Dépression Vacuum is the pressure in an enclosed space that is lower than the ambient pressure. relief. It is primarily used as a device Appareil A device is a pipe component that influences the media flow by opening, closing, or partially shutting off the flow channel or by dividing or mixing the media flow. for out-breathing in tanks, containers, and process equipment. It provides protection against vacuum and overpressure Surpression Overpressure refers to an increase in pressure in a system or vessel above the normal operating pressure. and prevents the intake of air and unallowable product vapor loss up to the set pressure Pression de réponse Set pressure is the gauge pressure at the device inlet at which the relief device is set to start opening under service conditions. . The valve can also be used as an in-breathing valve where the main valve is directly controlled when it is exposed to a vacuum, i.e., it functions as a weight-loaded diaphragm valve.
Tank Pressure Controls the Pilot Valve
The main valve is controlled by a pilot valve Soupape pilote The pilot valve is an assembly of a pilot operated valve, which is mounted on the main valve and is used to control the main valve. which is controlled by the tank pressure Pression de la cuve Tank pressure is the pressure within a tank. . A small amount of vapor is released into the atmosphere by the pilot valve when the valve opens. The set pressure is adjusted by increasing or decreasing the tension on the spring Ressort A spring is a spiral of wire which returns to its original shape after it is pressed or pulled. on the pilot valve.
Extreme Thightness
As the pressure increases, the closing force on the main valve increases, i.e., the valve becomes tighter with increasing tank pressure until the set pressure is reached. Once the valve has started to lift Course Lift is the actual travel of the valve pallet from the main valve out of the closed position. , it opens fully within a 10% of the pressure increase or opening pressure difference, and the nominal volume flow is released through a fully open valve. If and when this level is exceeded, the pressure increase will follow the performance curve (Δp/V. curve). From set pressure to full capacity (fully open valve), the pressure increase is 100% in case of vacuum venting/in-breathing function.
Advanced Manufacturing Technology
The tank pressure is maintained up to the set pressure with a tightness that is above the normal standards due to our highly developed manufacturing technology. This feature is ensured by valve seats made of high quality stainless steel with precisely lapped valve discs. After the overpressure is released or the vacuum is balanced, the valve re-seats and provides a tight seal Joint A seal prevents or limits unwanted transfer of product from one container to another. Seal is used as superordinate term for all types of sealing elements. .
Dimensions
To select the nominal size Diamètre nominal The nominal size is an alphanumeric designation of size for components in a piping system, used for reference purposes, comprising the letters DN followed by a dimensionless integer that is indirectly related to the physical size of the bore or outside diameter of the connections, expessed in millimeters. (DN), use the flow capacity charts on the folloeing pages
| DN1 | DN2 | a | b | c | d | e | f | g |
| 50 / 2" | 50 / 2" | 175 / 6.89 | 175 / 6.89 | 170 / 6.69 | 360 / 14.17 | 916 / 36.06 | 205 / 8.07 | 343 / 13.53 |
| 50 / 2" | 80 / 3" | 175 / 6.89 | 175 / 6.89 | 170 / 6.69 | 360 / 14.17 | 931 / 36.65 | 205 / 8.07 | 358 / 14.09 |
| 80 / 3" | 80 / 3" | 200 / 7.87 | 200 / 7.87 | 205 / 8.07 | 360 / 14.17 | 957 / 37.68 | 205 / 8.07 | 383 / 15.08 |
| 80 / 3" | 100 / 4" | 200 / 7.87 | 200 / 7.87 | 205 / 8.07 | 360 / 14.17 | 967 / 38.07 | 205 / 8.07 | 393 / 15.47 |
| 100 / 4" | 100 / 4" | 225 / 8.86 | 225 / 8.86 | 250 / 9.84 | 360 / 14.17 | 991 / 39.02 | 205 / 8.07 | 418 / 16.46 |
| 100 / 4" | 150 / 6" | 225 / 8.86 | 225 / 8.86 | 250 / 9.84 | 360 / 14.17 | 1001 / 39.41 | 205 / 8.07 | 428 / 16.85 |
| 150 / 6" | 150 / 6" | 300 / 11.81 | 250 / 9.84 | 335 / 13.19 | 500 / 19.69 | 1104 / 43.46 | 275 / 10.83 | 503 / 19.80 |
| 150 / 6" | 200 / 8" | 300 / 11.81 | 250 / 9.84 | 335 / 13.19 | 500 / 19.69 | 1124 / 44.25 | 275 / 10.83 | 523 / 20.59 |
| 200 / 8" | 200 / 8" | 375 / 14.77 | 300 / 11.81 | 410 / 16.14 | 630 / 24.80 | 1237 / 48.70 | 340 / 13.39 | 610 / 24.02 |
| 200 / 8" | 250 / 10" | 375 / 14.77 | 300 / 11.81 | 410 / 16.14 | 630 / 24.80 | 1267 / 49.88 | 340 / 13.39 | 640 / 25.20 |
| 250 / 10" | 250 / 10" | 425 / 16.73 | 350 / 13.78 | 500 / 19.69 | 790 / 31.10 | 1357 / 53.43 | 420 / 16.54 | 710 / 27.96 |
| 250 / 10" | 300 / 12" | 425 / 16.73 | 350 / 13.78 | 500 / 19.69 | 790 / 31.10 | 1377 / 54.41 | 420 / 16.54 | 730 / 28.74 |
| 300 / 12" | 300 / 12" | 500 / 19.69 | 400 / 15.75 | 570 / 22.44 | 920 / 36.22 | 1468 / 57.80 | 485 / 19.09 | 803 / 31.61 |
| 300 / 12" | 350 / 14" | 500 / 19.69 | 400 / 15.75 | 570 / 22.44 | 920 / 36.22 | 1488 / 58.59 | 485 / 19.09 | 823 / 32.40 |
| 300 / 12" | 400 / 16" | 500 / 19.69 | 400 / 15.75 | 570 / 22.44 | 920 / 36.22 | 1508 / 59.37 | 485 / 19.09 | 843 / 33.19 |
Dimensions in mm / inches
Material selection for housing
| Design | A | B | C |
| Housing | Aluminium | Stainless Steel | LTCS* (Low Temperature Carbon Steel) |
| Valve seat | Stainless Steel | Stainless Steel | Stainless Steel |
| Sealing - housing Corps A housing is a solid shell, which surrounds a content, either protecting the content from external influences, or protecting the environment from the content. | PTFE | PTFE | PTFE |
| Sealing – valve disc | metal - to - metal | metal - to - metal | metal - to - metal |
| Housing diaphragm | Stainless Steel | Stainless Steel | Stainless Steel |
| Pilot lines | Stainless Steel | Stainless Steel | Stainless Steel |
| Pilot housing | Aluminium | Aluminium/ Stainless Steel | Aluminium/ Stainless Steel |
| Pilot diaphragm | FEP | FEP | FEP |
* Special materials upon request
Flange connection type
| EN 1092-1; Form B1 |
| ASME B16.5 CL 150 R.F. |
Other types upon request
Coefficient of Discharge
| DN1 | 50 / 2" | 50 / 2" | 80 / 3" | 80 / 3" | 100 / 4" | 100 / 4" | 150 / 6" | 150 / 6" | 200 / 8" | 200 / 8" | 250 / 10" | 250 / 10" | 300 / 12" | 300 / 12" | 300 / 12" |
| DN2 | 50 / 2" | 80 / 3" | 80 / 3" | 100 / 4" | 100 / 4" | 150 / 6" | 150 / 6" | 200 / 8" | 200 / 8" | 250 / 10" | 250 / 10" | 300 / 12" | 300 / 12" | 350 / 14" | 400 / 16" |
| d0 | 54 / 2.13 | 54 / 2.13 | 83 / 3.27 | 83 / 3.27 | 108 / 4.25 | 108 / 4.25 | 160 / 6.30 | 160 / 6.30 | 208 / 8.19 | 208 / 8.19 | 262 / 10.31 | 262 / 10.31 | 310 / 12.20 | 310 / 12.20 | 310 / 12.20 |
| K | 0.57 | 0.83 | 0.75 | 0.79 | 0.69 | 0.85 | 0.7 | 0.8 | 0.65 | 0.8 | 0.62 | 0.76 | 0.62 | 0.72 | 0.8 |
DN1 = size inlet
DN2 = size outlet
d0 = orifice diameter(mm / inches)
K = coefficient of discharge
Design Types and Specifications
Following designs are available:Additional special devices available upon request.
* It is recommended that an external control line is to be provided with direct connection to the tank.
Druckeinstellungen
| Pressure: | +20 mbar | +1034 mbar |
| Vacuum: | -2.2 mbar | -7 mbar |
| -0.88 inch W.C. | -2.8 inch W.C. |
Other settings upon request
Flow Capacity Chart
The flow capacity charts have been determined with a calibrated and TÜV certified flow capacity test rig. Volume flow V in (m³/h) and CFH refer to the standard reference conditions of air ISO 6358 (20°C, 1bar). For conversion to other densities and temperatures refer to Sec. 1: “Technical Fundamentals”.
