Schroedahl ARV-Series

The Automatic Recirculation Valve (ARV) protects centrifugal pumps against overheating and cavitation problems by automatically maintaining a minimum flow when the system flow is in low load condition. The application itself is usually a closed loop application and consists of a suction and recirculation line from the tank and back to the tank. Typically the ARV is directly mounted on the pump discharge flange.

The valve system comprises a high quality check valve in the main line and a special control device for the minimum flow recirculation (the bypass control system). The general valve functioning is related to the process flow quantity – all SCHROEDAHL ARVs are flow sensitive.

product

Engineering Guidelines for ARV`s

Materials:

  • Standard temperature range from -196 °C to +260 °C (LP up to +400 °C)
  • Standard sealing material is EPDM, NBR, FKM, FFKM
  • SUL valves are available in CS and SS housing material only (cast body)
  • TD, MRM and MRK valves: CS, SS, LT, Duplex, Super Duplex

Special materials on request!

Differential Pressure at Rated Flow:

  • The differential pressure at rated flow (based on normal medium velocities of 4 to 5 m/s):
  • SUL approx. 0.3 bar
  • TDL approx. 0.4 bar
  • TDM approx. 1.0 bar (approximate figures, depending on load conditions)

Installation Conditions:

  • Preferred vertical, horizontal on request.
  • Preferred installation is directly on pump discharge flange, otherwise, if possible, no farther downstream than about 3 metres after the pump (depends on application).
  • Standard filter mesh size should be 0.3 to 0.5 mm (pump suction side). For commissioning we recommend a smaller filter size of 0.1 mm.

Examinations, Tests and Certificates:

  • Standard certificates acc. EN 10204 / 3.1 and 97/23/EG (PED for CE marking for Europe).
  • Leakage:
    Main Check Valve: FCI 70.2 Class IV (all valves)
  • Bypass: FCI 70.2 Class IV (only TDM / MRM valves); TDL and SUL are not tight closing (LP application).
  • Witnessed inspection by customer or third party inspection.
  • Non-destructive examinations on request for TD, MRM and MRK series (not for SUL type).
  • Bypass Kv Value test certificate, on request.
  • Flow curve for TDM, MRM and MRK series, on request.
 

Types

product features:
  • Automatically modulating bypass function
  • Cast material, carbon steel, stainless steel
  • Single-stage pressure reduction (up to 20 bar)
  • Internal operation (no external energy source required) – Easy to install
  • Low maintenance
  • Suitable for all liquids
TECHNICAL DATA:

product features:
  • Automatically modulating bypass function
  • Carbon steel or stainless steel
  • Special materials possible (e.g. Super Duplex)
  • Internal operation (no external energy source required) – Easy to install
  • Low maintenance
  • Suitable for all liquids
TECHNICAL DATA:

product features:
  • Automatically modulating bypass function
  • Forged housing material, carbon steel or stainless steel – Special materials possible (e.g. Super Duplex)
  • Internal operation (no external energy source required) – Easy to install
  • Low maintenance
  • Suitable for all liquids
TECHNICAL DATA:

product features:
  • Automatically modulating bypass function
  • Forged housing material, carbon steel or stainless steel
  • Special materials possible (e.g. Super Duplex)
  • Internal operation (no external energy source required)
  • Easy to install
  • Low maintenance
  • Suitable for all liquids
TECHNICAL DATA: