VN-A-PCPF

VN-A-PCPF

Pressure/Vacuum Relief Valve,
Pilot-operated diaphragm valve

Function and Description

The PROTEGO® Type VN-A-PCPF pilot-controlled diaphragm valve is a newly developed valve for pressure and vacuum relief. It is primarily used as a device for out-breathing in tanks, containers, and process equipment. It provides protection against vacuum and 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.

The main valve is controlled by a pilot valve which is controlled by the tank pressure. 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 on the pilot valve.

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, 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.

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.

Features and Advantages

  • controlled by corrosion-resistant control valve (pilot valve)
  • small amounts of tank substance is released into the atmosphere when the valve is opened
  • 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
  • protection of the main valve control diaphragm from low temperatures – high durability
  • high flow capacity
  • can be used in explosion hazardous areas
  • field test connection possible upon request
  • field test kit upon request

Dimensions

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

DN1 DN2 abcdefg
100 / 4"100 / 4"225 / 8.86225 / 8.86250 / 9.84360 / 14.17991 / 39.02205 / 8.07418 / 16.46
100 / 4"150 / 6"225 / 8.86225 / 8.86250 / 9.84360 / 14.171001 / 39.41205 / 8.07428 / 16.85
150 / 6"150 / 6"300 / 11.81250 / 9.84335 / 13.19500 / 19.691104 / 43.46275 / 10.83503 / 19.80
150 / 6"200 / 8"300 / 11.81250 / 9.84335 / 13.19500 / 19.691124 / 44.25275 / 10.83523 / 20.59
200 / 8"200 / 8"375 / 14.77300 / 11.81410 / 16.14630 / 24.801237 / 48.70340 / 13.39610 / 24.02
200 / 8"250 / 10"375 / 14.77300 / 11.81410 / 16.14630 / 24.801267 / 49.88340 / 13.39640 / 25.20
250 / 10"250 / 10"425 / 16.73350 / 13.78500 / 19.69790 / 31.101357 / 53.43420 / 16.54710 / 27.96
250 / 10"300 / 12"425 / 16.73350 / 13.78500 / 19.69790 / 31.101377 / 54.41420 / 16.54730 / 28.74
300 / 12"300 / 12"500 / 19.69400 / 15.75570 / 22.44920 / 36.221468 / 57.80485 / 19.09803 / 31.61
300 / 12"350 / 14"500 / 19.69400 / 15.75570 / 22.44920 / 36.221488 / 58.59485 / 19.09823 / 32.40
300 / 12"400 / 16"500 / 19.69400 / 15.75570 / 22.44920 / 36.221508 / 59.37485 / 19.09843 / 33.19
DN1 DN2 abcdefg
100 / 4"100 / 4"225 / 8.86225 / 8.86250 / 9.84360 / 14.17991 / 39.02205 / 8.07418 / 16.46
100 / 4"150 / 6"225 / 8.86225 / 8.86250 / 9.84360 / 14.171001 / 39.41205 / 8.07428 / 16.85
150 / 6"150 / 6"300 / 11.81250 / 9.84335 / 13.19500 / 19.691104 / 43.46275 / 10.83503 / 19.80
150 / 6"200 / 8"300 / 11.81250 / 9.84335 / 13.19500 / 19.691124 / 44.25275 / 10.83523 / 20.59
200 / 8"200 / 8"375 / 14.77300 / 11.81410 / 16.14630 / 24.801237 / 48.70340 / 13.39610 / 24.02
200 / 8"250 / 10"375 / 14.77300 / 11.81410 / 16.14630 / 24.801267 / 49.88340 / 13.39640 / 25.20
250 / 10"250 / 10"425 / 16.73350 / 13.78500 / 19.69790 / 31.101357 / 53.43420 / 16.54710 / 27.96
250 / 10"300 / 12"425 / 16.73350 / 13.78500 / 19.69790 / 31.101377 / 54.41420 / 16.54730 / 28.74
300 / 12"300 / 12"500 / 19.69400 / 15.75570 / 22.44920 / 36.221468 / 57.80485 / 19.09803 / 31.61
300 / 12"350 / 14"500 / 19.69400 / 15.75570 / 22.44920 / 36.221488 / 58.59485 / 19.09823 / 32.40
300 / 12"400 / 16"500 / 19.69400 / 15.75570 / 22.44920 / 36.221508 / 59.37485 / 19.09843 / 33.19

Dimensions in mm / inches

VN-A-PCPF

Material selection for housing

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
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

VN-A-PCPF

Flange connection type

EN 1092-1; Form B1
ASME B16.5 CL 150 R.F.
EN 1092-1; Form B1
ASME B16.5 CL 150 R.F.

Other types upon request

Coefficient of Discharge

DN1100 / 4"100 / 4"150 / 6"150 / 6"200 / 8"200 / 8"250 / 10"250 / 10"300 / 12"300 / 12"300 / 12"
DN2100 / 4"150 / 6"150 / 6"200 / 8"200 / 8"250 / 10"250 / 10"300 / 12"300 / 12"350 / 14"400 / 16"
d0108 / 4.25108 / 4.25160 / 6.30160 / 6.30208 / 8.19208 / 8.19262 / 10.31262 / 10.31310 / 12.20310 / 12.20310 / 12.20
K0.690.850.70.80.650.80.680.760.620.720.8
DN1100 / 4"100 / 4"150 / 6"150 / 6"200 / 8"200 / 8"250 / 10"250 / 10"300 / 12"300 / 12"300 / 12"
DN2100 / 4"150 / 6"150 / 6"200 / 8"200 / 8"250 / 10"250 / 10"300 / 12"300 / 12"350 / 14"400 / 16"
d0108 / 4.25108 / 4.25160 / 6.30160 / 6.30208 / 8.19208 / 8.19262 / 10.31262 / 10.31310 / 12.20310 / 12.20310 / 12.20
K0.690.850.70.80.650.80.680.760.620.720.8

DN1 = size inlet
DN2 = size outlet
d0 = orifice diameter(mm / inches)
K =  coefficient of discharge

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

VN-A-PCPF

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

VN-A-PCPF

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
+8 inch W.C. +415.1 inch W.C.

Vacuum:

-2.0 mbar -7 mbar
-0.8 inch W.C. -2.8 inch W.C.
Higher or lower settings upon request
VN-A-PCPF

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”.

VN-A-PCPF
VN-A-PCPF