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VN-A-PCPM

Pressure/Vacuum Relief Valve Pilot-operated diaphragm valve

  • controlled by corrosion-resistant, low-temperature-resistant permanent magnet
  • no continuous flow of the tank substance through the pilot valve
  • pop-open characteristic from the lowest pressure increase up to full lift
  • max. 10% pressure increase up to full lift
  • extreme tightness, resulting in lowest possible product losses and reduced environmental pollution
  • set pressure close to opening pressure for optimum pressure maintenance in the system
  • high flow capacity
  • protection of the main valve control diaphragm from low temperatures – high durability
  • can be used in explosion hazardous areas
  • designed for use at low temperatures
  • automatic condensate drain
  • Field test connection possible upon request
  • Field test kit upon request

Función y Descripción

The  PROTEGO® VN-A-PCPM pilot-operated diaphragm valve is a highly developed valve for pressure and vacuum relief. It is primarily used as a safety device for out-breathing in tanks, containers, and process equipment. It provides protection against unallowable overpressure and prevents the intake of air and unallowable product vapor loss up to the set pressure.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. It is ideally suitable for both atmospheric conditions and for use in low temperatures.

The main valve (2) is controlled by a pilot valve (1). The pilot valve is controlled by the tank pressure. The tank substance does not continuously flow through the pilot. The set pressure is adjusted on the pilot valve by a corrosion-resistant and low-temperature- resistant permanent magnet.

As the operating pressure increases, the closing force at the main valve also increases; i.e., the valve tightness increases until the set pressure is reached to prevent leakage. After the valve responds, it immediately opens completely without any significant increase in pressure (pop-open characteristic), and the nominal volumetric flow is released through a fully open valve. If this is exceeded, the pressure increase follows the volume flow (Δp/V̇ curve). From set pressure to full capacity (fully open valve), the pressure increase is 100% in case of vacuum venting/in-breathing function.

The tank pressure is maintained up to the set pressure with a tightness that is above the normal standards due to our state-of-the art manufacturing. This feature is ensured by valve seats made of high quality stainless steel with precisely lapped valve pallets. After the overpressure is released or the vacuum is balanced, the valve re-seats and provides a tight seal.

Dimensiones

To select the nominal size (DN), use the flow capacity charts on the following pages

DN1 DN2 abcdefg
50 / 2"50 / 2"175 / 6.89175 / 6.89170 / 6.69360 / 14.17838 / 32.99205 / 8.07371 / 14.61
50 / 2"80 / 3"175 / 6.89175 / 6.89170 / 6.69360 / 14.17853 / 33.58205 / 8.07386 / 15.20
80 / 3"80 / 3"200 / 7.87200 / 7.87205 / 8.07360 / 14.17878 / 34.57205 / 8.07411 / 16.18
80 / 3"100 / 4"200 / 7.87200 / 7.87205 / 8.07360 / 14.17888 / 34.96205 / 8.07421 / 16.57
100 / 4"100 / 4"225 / 8.86225 / 8.86250 / 9.84360 / 14.17913 / 35.94205 / 8.07446 / 17.56
100 / 4"150 / 6"225 / 8.86225 / 8.86250 / 9.84360 / 14.17923 / 36.34205 / 8.07456 / 17.95
150 / 6"150 / 6"300 / 11.81250 / 9.84335 / 13.19500 / 19.691025 / 40.35275 / 10.83531 / 20.91
150 / 6"200 / 8"300 / 11.81250 / 9.84335 / 13.19500 / 19.691045 / 41.14275 / 10.83551 / 21.69
200 / 8"200 / 8"375 / 14.77300 / 11.81410 / 16.14630 / 24.801237 / 48.70340 / 13.39638 / 25.12
200 / 8"250 / 10"375 / 14.77300 / 11.81410 / 16.14630 / 24.801188 / 46.77340 / 13.39668 / 26.30
250 / 10"250 / 10"425 / 16.73350 / 13.78500 / 19.69790 / 31.101278 / 50.31420 / 16.54738 / 29.05
250 / 10"300 / 12"425 / 16.73350 / 13.78500 / 19.69790 / 31.101298 / 51.10420 / 16.54758 / 29.84
300 / 12"300 / 12"500 / 19.69400 / 15.75570 / 22.44920 / 36.221389 / 54.58485 / 19.09831 / 32.72
300 / 12"350 / 14"500 / 19.69400 / 15.75570 / 22.44920 / 36.221409 / 55.47485 / 19.09851 / 33.50
300 / 12"400 / 16"500 / 19.69400 / 15.75570 / 22.44920 / 36.221429 / 56.26485 / 19.09871 / 34.29
Dimensiones en mm / pulgadas

Selección de materiales para la vivienda

DesignA B C
HousingAluminiumStainless Steel LTCS* (Low Temperature Carbon Steel)
Valve seatStainless Steel Stainless Steel Stainless Steel
Sealing - housingPTFEPTFEPTFE
Sealing – valve discmetal - to - metal metal - to - metal metal - to - metal
Housing diaphragmStainless Steel Stainless Steel Stainless Steel
Pilot linesStainless Steel Stainless Steel Stainless Steel
Pilot housingAluminiumAluminium/ Stainless Steel Aluminium/ Stainless Steel
Pilot diaphragmFEPFEPFEP
* Special materials upon request

Tipo de bridas de conexión

EN 1092-1; Form B1
ASME B16.5 CL 150 R.F.
Other types upon request

Coefficient of Discharge

DN150 / 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"
DN250 / 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"
d054 / 2.1354 / 2.1383 / 3.2783 / 3.27108 / 4.25108 / 4.25160 / 6.30160 / 6.30208 / 8.19208 / 8.19262 / 10.31262 / 10.31310 / 12.20310 / 12.20310 / 12.20
K0.570.750.630.710.600.750.640.780.630.760.620.730.630.680.74
DN1 = size inlet
DN2 = size outlet
d0 = orifice diameter(mm / inches)
K =  coefficient of discharge

Basic design of pressure/vacuum relief valve with a pilot valve

Basic pressure/vacuum relief valve with a pilot valve

VN-A-PCPM

Additional special devices available upon request.
* It is recommended that an external control line is to be provided with direct connection to the tank.

Settings

Pressure: +20 mbar +1034 mbar
Vacuum: -2.0 mbar -7 mbar
-0.8 inch W.C. -2.8 inch W.C.
Higher or lower settings upon request.

Diagrama de flujo volumétrico

Los diagramas de flujo volumétrico han sido determinados con un banco de pruebas de caudal calibrado y certifi - cado por TÜV. El flujo volumétrico V. en [m³/h] y el CFH se refi eren a las condiciones estándar de referencia de aire según ISO 6358 (20°C, 1bar). La conversión a otras densidades y temperaturas están referidas en el Vol. 1: “Fundamentos Técnicos”.