SAVA

Special cross-over combinations for Safety (Relief) valves

DIN: 25E – 500E / PN 10 – 40
ASME: NPS 1″E – 20“E / class  150 300
PT range: -30 < T < 230/280°C, vacuum 10-8 mbar

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SPEC SHEET
CERTIFICATE
Design Features

Design Characteristics

  • full-flow, round bore
  • cavity free (no medium contact of sealing surfaces)
  • tight for years (DIN EN 12266-1)
  • safe exchange of safety valves
  • transflow during cross-over action
  • operation errors impossible design-wise
  • safe backflow of blow off capacity
  • economic combination of different valve sizes
  • TÜV approved

The basic principle of the safety valve exists therein, that dependent on the construction, a least cross section (Amin) is guaranteed during the cross-over phase from safety valve I to safety valve II. Therefore a minimal flow (protection of the vessel) is always given.

PT-Diagramm

Operating temperatures < -30°C and > 220 °C have to be checked and approved by AZ according to the operating conditions.

Besides the P/T value of the sleeve the limitations of the valve bodies also have to be considered. Please refer to the EN 12516-1 resp. ASME B16.34 in order to choose a proper pressure rating (PN/class). The shown values refer to austenitic stainless steel 1.4408 (A351 Gr. CF8M).

1) For operating temperatures below -10°C low temperature / austenitic steels are required.
2) Sleeve: There are different sleeve materials / compounds available.

Materials

Standard body materials

  • Carbon Steel 1.0619, ASTM A216 WCB
  • Stainless Steel 1.4408, ASTM A351 CF8M
  • Stainless Steel 1.4308, ASTM A351 CF8
  • Unalloyed stainless steel casting (low Temp.) 1.1138, LCC/LCB/A352

Standard plug materials

  • Stainless Steel 1.4408, ASTM A351 CF8M
  • Stainless Steel 1.4308, ASTM A351 CF8

Special materials

  • Alloy
  • Monel
  • Nickel
  • Zirconium
  • Titan
  • Tantal
  • other materials on request
Sealing Systems

Type STD

Standard sealing for all major applications;
Tmax 230°C

Type FS

Firesafe sealing (API 607) with graphite packing for additional
stem sealing; Tmax 230°C

Type CA

Chemical sealing to prevent fugitive emission of aggressive and toxic media
with PTFE packing for additional stem sealing; Tmax 230°C

Type FSN

Firesafe safety sealing (API 607) for fluctuating temperatures
with 3x graphite packing (adjustable) for additional
stem sealing; Tmax 280°C

Type FSN-SL

Firesafe safety sealing (API 607) for fluctuating temperatures
with 3x graphite packing (live loaded disc springs) for additional
stem sealing; Tmax 280°C

Type CASN

Chemical safety sealing for fluctuating temperatures
with 3x PTFE packing (adjustment) for additional stem sealing;
Tmax 230°C

Type CASN-SL

Chemical safety sealing for fluctuation temperatures
with 3x PTFE packing (live loaded disc springs) for additional
stem sealing; Tmax 230°C

Dimensions

For geometric reasons, threads are used in the flange bores in a few cases

Actuation

1 Locking Devices
Pilot valve combinations, pad lock eyelets, linear key conception, indexing plunger arrestor.

2 Plug stem extension
Solid construction in stainless steel with T-wrench, Standard extension 100 mm or 150 mm, non standard lengths are available on request

3 Actuators
Actuators for mounting-flange acc. to DIN ISO 5211

NEW: Pneumatic actuator AIR GEAR for plug valves with high torque =150.000 Nm

4 Ratched coupling
To usw on multiport valves with standard 90° actuator for bigger switchpositions than 90°

5 Cover extension
Solid construction in stainless steel, Standard extension 100 mm or 150 mm high,  non standard lengths are available on request . Hexagonal bolts on adjustment ring freely accessible. Note: Don’t use with sealing FSN/FSN-SL and CASN/CASN-SL