FNW 721 Installation Manual

FNW Thermoplastic Butterfly Valve

Operating, Installation & Maintenance

Manual

Phone: [phone] • Fax: [phone]

FNW

www.fnwvalve.com

FNW

4120 NE Columbia Blvd, Portland, OR 97211

PH: 503-287-8383; Fax: [phone]

Installation Instructions For FNW PVC Butterfly Valves

FNW RECOMMENDS READING THE FOLLOWING INFORMATION PRIOR TO INSTALLING AND USING
OUR VALVES, STRAINERS, CONTROLS AND OTHER ASSOCIATED PRODUCTS.

FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN SERIOUS INJURY.

1. FNW guarantees its products against defective material and workmanship only. FNW assumes no
responsibility for damage or injuries resulting from improper installation, misapplication, or abuse of any
product.

2. FNW assumes no responsibility for damage or injury resulting from chemical incompatibility between
its products and the process fluids to which they are subjected. Compatibility charts provided in FNW
literature are based on ambient temperatures of 70F and are for reference only. Customer should always test
to determine application suitability.

3. Consult FNW literature to determine operating pressure and temperature limitations before installing
any FNW product. Note that the maximum recommended fluid velocity through any FNW product
is eight feet per second. Higher flow rates can result in possible damage due to the water hammer effect.
Also note that maximum operating pressure is dependent upon material selection as well as operating
temperature.

4. FNW products are designed primarily for use with non-compressible liquids. They should NEVER be
used or tested with compressible fluids such as compressed air or nitrogen.

5. Systems should always be depressurized and drained prior to installing or maintaining FNW products.

6. Temperature effect on piping systems should always be considered when the systems are initially designed.
Piping systems must be designed and supported to prevent excess mechanical loading on FNW equipment
due to system misalignment, weight, shock, vibration, and the effects of thermal expansion and contraction.

7. Because PVC and CPVC plastic products become brittle below 40F, FNW recommends caution in their
installation and use below this temperature.

8. Published operating torque requirements are based upon testing of new valves using clean water at 70F.
Valve torque is affected by many factors including fluid chemistry, viscosity, flow rate, and temperature. These
should be considered when sizing electric or pneumatic actuators.

9. Due to differential thermal expansion rates between metal and plastic, transmittal of pipe vibration,
and pipe loading forces DIRECT INSTALLATION OF METAL PIPE INTO PLASTIC CONNECTIONS IS NOT
RECOMMENDED. Wherever installation of plastic valves into metal piping systems is necessary, it is
recommended that at least 10 pipe diameter in length of plastic pipe be installed upstream and downstream
of the plastic valve to compensate for the factors mentioned above.

Installation Instructions

1. DESCRIPTION
The FNW PVC wafer style butterfly valve is supplied with guide lugs for making connections to the piping system in
which it is installed. These valves are available in PVC, with a choice of flexible seal materials (EPDM, FPM).
Installation, operation and maintenance of these valves will be the same regardless of the materials of construction.