DV/ZT

DV/ZT

Pressure and Vacuum Relief Valve, In-Line

Function and Description

The PROTEGO® in-line valve DV/ZT is a state-of-the-art pressure and vacuum relief valve. Typically the valve is installed in the in- and out-breathing lines of tanks, vessels and process apparatus to protect against unallowable high and low pressure. The valve prevents emission losses almost up to the set pressure and provides protection from product entry into the system. Due to its design the lower valve pallet is one size smaller than the upper valve pallet.

The device will start to open as soon as the set pressure is reached and only requires 10% overpressure to full lift. Continuous investments into 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 just 10% below the maximum allowable working pressure or vacuum (MAWP or MAWV) of the tank and still safely vent the required mass flow. Due to our highly developed manufacturing technology the tank pressure is maintained up to set pressure with a tightness that is far superior to the conventional standard. This feature is facilitated 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 excess pressure is discharged or vacuum is balanced, the valve reseats 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 work, which allow a stable operation of the valve pallet and optimized performance resulting in reduction of product losses.

Features and Advantages

  • “full lift type” technology valve utilizes only 10% overpressure to reach full lift
  • high performance seal reducing product loss below EPA’s 500ppm rule preventing environmental pollution
  • based on 10% technology the set pressure is close to the opening pressure which results in best possible pressure management of the system compared to conventional 40%- or 100%- technology valves
  • optimized flow performance, which reduces capital cost to a minimum as smaller sized valves may be used
  • can be installed in explosion hazardous areas
  • housing designed to 150 psi (PN 10)
  • maintenance friendly design
DV/ZT
Tankanschluss ist abhängig von den geforderten Volumenströmen und Druckeinstellungen für Ent- und Belüftung.
Detail X
Detail X
DV/ZT
Tankanschluss ist abhängig von den geforderten Volumenströmen und Druckeinstellungen für Ent- und Belüftung.
Detail X
Detail X

Design Types and Specifications

The valve pallets are weight loaded. Higher set pressures are achieved by using spring loaded type DV/ZT-F
Two different designs are available:

In-line pressure and vacuum relief valve, standard design

DV/ZT - –

In-line pressure and vacuum relief valve with heating jacket

DV/ZT - H

In-line pressure and vacuum relief valve, standard design

DV/ZT - –

In-line pressure and vacuum relief valve with heating jacket

DV/ZT - H

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

Upper valve pallet:

±2.0 mbar ±60 mbar
±0.8 inch W.C. ±24 inch W.C.

Lower valve pallet:

±3.5 mbar ±50 mbar
±1.4 inch W.C. ±20 inch W.C.
For higher set pressure refer to type DV/ZT-F.
Lower set vacuum upon request.
DV/ZT
Tankanschluss ist abhängig von den geforderten Volumenströmen und Druckeinstellungen für Ent- und Belüftung.
Detail X
Detail X

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”.

DV/ZT
Tankanschluss ist abhängig von den geforderten Volumenströmen und Druckeinstellungen für Ent- und Belüftung.
Detail X
Detail X
DV/ZT
Tankanschluss ist abhängig von den geforderten Volumenströmen und Druckeinstellungen für Ent- und Belüftung.
Detail X
Detail X