Check Valves with Free Swing Requirements

Problem

Typically, Bleeder Trip/Non Return Extraction Steam Check Valves are required to meet “free swing” requirements to insure the main turbine is adequately protected. To meet this “free swing” requirement of the disc requires that valve packing loads are light and DO NOT prevent “free swing”. Typically in the compromise to achieve “free swing” the packing leaks.

Solution

To achieve a successful compromise between the “free swing” ability of the check and “leak-free” service from the valve packing, a very low friction packing set is required. For low temperature applications (ie < 400 Degrees F), a successful packing set has been either AP Style 5000 with or without AP Style 5718. Other factors to consider are:

• Limited number of packing rings to 3-4
• Fully torque each packing ring as it is installed
• Use Carbon bushings on the front and back to maintain alignment

Product Info

AP STYLE 5000

AP STYLE 5005/5010