Operating Instructions for ERHARD NON SLAM Nozzle Check Valve
1
Description of Product and Performance
ERHARD NON SLAM Nozzle Check Valves (EDRV)
DN 80 – 600, PN10 – PN40 Product No. 435...00
The ERHARD NON SLAM Nozzle Check Valve is a non-return valve of compact design
and short pattern, with central rubber-coated valve disc (DN 80-300) or valve ring (DN
350-600) which opens and closes in axial direction, the closing movement being spring-
assisted.
Thanks to the materials and the sealing and corrosion protection systems, the
ERHARD NON SLAM Nozzle Check Valve is suitable for application in the water
industry (mechanically neutral water up to a max. temperature of 60° C) and for pre-
treated sewage.
In case of hot flow media, there is the risk of burns and the valve has to be heat-
insulated by the user.
The normal range of flow velocity of the ERHARD NON SLAM Nozzle Check Valve is
0,5 – 5 m/s (referred to the nominal size DN). At a velocity of 2 m/s (referred to DN) the
ERHARD NON SLAM Nozzle Check Valve is used in a fully economical way. With
these velocities, all nominal sizes are in fully open position.
For opening the ERHARD NON SLAM Nozzle Check Valve , according to DN, 0,5 – 0,9
mWC (50 – 90 mbar) as minimum differential pressure is necessary. The valve opens at
this differential pressure and the medium begins to flow. For tight closure, a minimum
back pressure of approx. 4.0 mWC (400 mbar) is necessary for DN 80 – 300 and of
approx. 8 mWC (800 mbar) for DN 350 – 600.
BA43E000
Juli 2009
Rev.9
ERHARD GmbH & Co. KG
x
D-89502 Heidenheim
x
Postfach 1280
Telefon: (07321) 320-0
(07321) 320 491 E-Mail: info
@
erhard.de
Internet: http://www.erhard.de
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