Flowserve 50165 Nordstrom Figure - Manual (Page 4)

Nordstrom Figure 50165 and 50169 Dynamic Balance Iron Plug Valve FCD NVENIM2006-00 – 09/05

Introduction
It is beyond the scope of this manual to make recommendations for specific applications because
misapplication of a valve type could result in operating problems that adversely affect system safety and
efficiency. This manual is intended to call attention to important considerations in the selection of valves.
The manual addresses the important subjects of Shipping and Storage, Installation, and Operation and
Maintenance. Observance of the recommendations and cautions offered herein will provide increased
assurance of satisfactory valve performance.
The valve industry offers a wide variety of valve types and materials for use in industrial piping
applications. There are usually several possible choices for a given requirement; any one valve may offer
significant advantages and/or limitations compared to another valve. It is good practice to consult the
manufacturer regarding specific requirements. The purchasing function includes the responsibility for
securing the required valves at the lowest cost, but must also ensure that the valves purchased are in
fact satisfactory for the intended service. The lowest total user (life cycle) cost criteria should be used
only in choosing between alternatives that are known to satisfy the service requirement.
Pressure/Temperature Rating
The pressure/temperature rating of the valve must be properly selected for the service requirement.
If the service involves a temperature above 100ºF (38ºC), the valve pressure rating at the service
temperature must be verified as meeting the requirements of the application.
If system testing will subject the valve to a pressure in excess of its working pressure rating, then the
intended testing pressure and a statement explaining whether the test pressure is through the opened
valve or a differential across the closed valve, should be included in the purchase specification.
Some Source References for Pressure-Temperature Ratings: MSS SP-78; Cast Iron Plug Valves,
Flanged and Threaded Ends
1
Valve Selection