Caractéristiques
Fonction et description
Pressure and Vacuum Relief Valve with Flange Connection for a Vent Line
The PROTEGO® In-Line Valve DV/ZW is a state-of-the-art Pressure and Vacuum Relief Valve with separate flange connections for use in a vent line. Typically, the valve is installed in the in-breathing and out-breathing lines of tanks, vessels, and process equipment to protect against unallowable overpressure and underpressure. The valve prevents emission losses almost up to the set pressure and prevents air intake almost up to set vacuum. It is designed in a way that if the set pressure is exceeded, the vapors are released into an exhaust pipe (e.g., Vent Header). If the set vacuum is exceeded, atmospheric air is pulled into the system. For structural reasons, the vacuum valve pallet is one size smaller than the pressure valve pallet.
Full Lift Technology
The device will start to open as soon as the set pressure is reached and only requires 10% overpressure to full lift. Continuous investments in and a commitment to research and development have allowed PROTEGO® to develop a low pressure valve which has the same opening characteristic as a high pressure safety relief valve. This “Full Lift Type” technology allows the valve to be set at just 10% below the maximum allowable working pressure or vacuum ( MAWP Maximal erlaubter Betriebsdruck (MAWP) Maximaler zulässiger Überdruck im oberen Bereich eines kompletten Behälters in normaler Betriebsstellung bei der genannten übereinstimmenden Temperatur, die für diesen Druck spezifiziert ist. or MAWV) of the tank and still safely vent the required mass flow. The opening characteristic of the pressure and vacuum side is basically the same. However, the in-breathing will start as soon as the differential pressure between the atmospheric pressure and the tank is greater than the set pressure of the vacuum valve pallet. Due to our highly developed manufacturing technology, the tank pressure is maintained up to set pressure with a tightness that is far above the conventional standard.
Optimized Valve Design for Maximum Performance
This feature is ensured by valve seats made of high quality stainless steel and with individually lapped valve pallets (1), or with an air cushion seal (2), in conjunction with high quality FEP diaphragm. The valve pallets are also available with a PTFE seal to prevent the valve pallets from sticking when sticky products are used and to enable the use of corrosive fluids. After the over pressure is released or the vacuum is balanced, the valve re-seats and provides a tight seal. The optimized fluid dynamic design of the valve body and valve pallet is a result of many years of research, resulting in stable operation of the valve pallet, optimized performance, and reduced product losses.
Dimensions
To select the nominal size (DN), please use the flow capacity charts on the following pages
| DN | 40 / 1½“ | 50 / 2" | 80 / 3" | 100 / 4" | 150 / 6" |
| a | 280 / 11.02 | 280 / 11.02 | 340 / 13.39 | 390 / 15.35 | 520 / 20.47 |
| b | 230 / 9.06 | 230 / 9.06 | 240 / 9.45 | 290 / 11.42 | 330 / 12.99 |
| c | 85 / 3.35 | 85 / 3.35 | 125 / 4.92 | 140 / 5.51 | 185 / 7.28 |
| d | 210 / 8.27 | 210 / 8.27 | 280 / 11.02 | 310 / 12.20 | 390 / 15.35 |
Dimensions in mm / inches
Larger sizes upon request
Dimensions for pressure and vacuum relief valve with heating jacket upon request
Material selection for housing
| Design | A | B |
| Housing | Steel | Stainless Steel |
| Heating jacket (DV / ZW-H-...) | Steel | Stainless Steel |
| Valve seat | Stainless Steel | Stainless Steel |
| Gasket | PTFE | PTFE |
Option: Housing with ECTFE-lining
Special materials upon request
Material selection for pressure valve pallet
| Design | A | B | C | D |
| Pressure range [mbar] [inch W.C.] | +2.0 up to +3.5 +0.8 up to +1.4 | >+3.5 up to +14 >+1.4 up to +5.6 | >+14 up to +60 >+5.6 up to +24 | >+14 up to +60 >+5.6 up to +24 |
| Valve pallet | Aluminium | Stainless Steel | Stainless Steel | Stainless Steel |
| Sealing | FEP | FEP | Metal to Metal | PTFE |
Special materials upon request
For higher set pressures refer to type DV/ZW-F.
Material selection for vacuum valve pallet
| Design | A | B | C | D | E | F |
| Pressure range [mbar] [inch W.C.] | -3.5up to -5.0 -1.4up to -2.0 | <-5.0 up to -14 <-2.0up to -5.6 | <-14up to -35 <-5.6 up to -14 | <-35 up to -50 <-14 up to -20 | <-14 up to -35 <-5.6 up to -14 | <-35 up to -50 <-14 up to -20 |
| Valve pallet | Aluminium | Stainless Steel | Stainless Steel | Stainless Steel | Stainless Steel | Stainless Steel |
| Sealing | FEP | FEP | Metal to Metal | Metal to Metal | PTFE | PTFE |
Special materials and lower set vacuum upon request.
Flange connection type
| EN 1092-1; Form B1 |
| ASME B16.5 CL 150 R.F. |
other types upon request
Design Types and Specifications
The valve pallets are weight loaded. Higher set pressures are achieved by using spring loaded type DV/ZW-FTwo different designs are available:
Additional special devices available upon request
Within piping systems the influence of backpressure has to be considered in deciding the set pressure and opening characteristics. For special design solutions (e.g. partial load operation) the valve can be supplied with standard valve pallets (with proportional opening function).
Settings
| Pressure: | +2.0 mbar | +60 mbar |
| +0.8 inch W.C. | +24 inch W.C. | |
| Vacuum: | -3.5 mbar | -50 mbar |
| -1.4 inch W.C. | -20 inch W.C. |
For higher set pressure refer to type DV/ZW-F.
Lower set vacuum 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”.
