Cla-Val DBF Series - Manual

Installation Procedures For DBF Style Check Valves
The Cla-Val Model DBF Series is a flanged, bolt-on duckbill Check
Valve manufactured with top quality elastomeric materials.
Custom engineered and manufactured for each application, its
design allows maximum flow with minimal pressure drop across
the valve. This flexible valve prevents flow from occurring in the
reverse direction. It will eliminate costly backflow from oceans,
rivers, or storm water and is the ideal valve for effluent diffuser sys-
tems.
The Cla-Val Model DBF Series duckbill Check Valve is designed to
bolt on to an existing pipe flange (PVC, Concrete, Steel, etc) and
is held in place with bolted into place in tandem with retaining rings.
Installation is quick and simple. These valves require no external
power source or mechanical components to operate, unlike con-
ventional Check Valves. The Cla-Val Duckbill Check Valves
require little or no maintenance, thereby virtually eliminating oper-
ation and maintenance costs.
The Cla-Val Model DBF Series Check Valve can handle corrosive
or abrasive materials such as raw sewage, sludge, or slurries.
With a broad selection of elastomers, the Check Valve is suitable
for many types of media and a wide range of temperatures.
Normal Check Valve Operation:
Cla-Val Duckbill Check Valves are custom made and are intended
for specific applications. They are designed to respond to criteria
unique to its purpose, such as line pressure, backflow pressures,
and chemical compatibility. Should the conditions be altered or
changed significantly, it could affect the normal operation of the
valve. The Cla-Val duckbill check valves function is based on dif-
ferential pressure. When the line pressure, (at the valve inlet),
exceeds the backpressure, (at the valve outlet), the valve opens
and flow is created (Figure 1 - left picture). When the backpres-
sure exceeds or overcomes the line pressure, the bill of the valve
seals shut, thereby preventing any backflow from occurring, (Figure
1 - right picture).
Storage Procedures:
• Duckbill check valves should be stored vertically (Figure 2a) with
the bill facing upward, not on its side, (Figures 2b) in a cool, dry
location with maximum ventilation.
• Check valves should not be stacked nor should anything be
stored on top of the valves’ bills. They should remain on a skid
until ready for use.
• Do not drop, bend, or twist the valve as damage may occur.
• The valve should be wrapped in black plastic to avoid contact with
sunlight and/or ultra-violet light. This will extend the shelf life.
• Avoid exposure to light, electric motors, dirt, or chemicals.
Resilient check valves are subject to deterioration when exposed
to ozone and non-compatible chemicals. Ozone, especially, may
cause the rubber to harden and become brittle.
• Store the Installation Operation Manual with the valve so it will be
readily available for installation.
Components and Terminology (refer to diagram below)
Cuff: The round portion of the valve connecting the flange to the
valve taper.
Taper: The taper transforms the round shape of the valve cuff to
the vertical shape of the valve bill. Reinforcement in the taper is
customized to suit each application’s expected inlet pressures and
backpressures.
Bill: The outlet end of the valve. The bill contorts to allow flow
through the valve yet closes tight during ‘no flow’ or reverse pres-
sure conditions. The bill can be straight or curved (depends on
application).
Tube: The inner surface or valve ‘sleeve’. This is constructed using
an elastomer most suitable for the process fluid.
Cover: The outer surface of the valve. This is made from an elas-
tomer most suitable for the expected operating conditions (usually
made from EPDM due to its resistance to light and heat).
Retaining Ring: Supplied with the valve, the duckbill flange is
‘sandwiched’ between the mating pipe flange and the retaining
ring.
Line Pressure: The fluid pressure applied to the valve inlet (used
to open the valve).
Backpressure: The fluid pressure exerted on the valve outlet.
Usually measured in feet or meters of fluid above the pipe invert.
Installation Procedures:
Preferred Orientation
The bill of the check valve should be installed as close to the ver-
tical position as possible. In cases where clearance below the pipe
outlet is minimal, the duckbill should be rotated only enough as
required to avoid contact with the ground. Please contact your
Cla-Val Factory to discuss this application.
1. Remove all burrs or sharp edges from the pipe flange faces
and wipe clean of oil, grease, etc. Apply a thin coat of graphite or
glycerine to the pipe flange face. This will ease installation and
allow for easy removal at a later date.
Duckbill Check Valves Flanged Style
DBF
SERIES
INSTALLATION / OPERATION / MAINTENANCE
The Duckbill Series valve allows
material to flow through...
...and then prevents it from
returning to its source.
Figure 1
YES
Figure 2a
NO
Figure 2b