VALVE MAGAZINE Summer 2023

times supplied with springs to aid in closing and/or equalizing pipes to aid overall performance. SUMMARY Although similar to their ancestors in concept, today’s pressure seal valves have evolved to address a wider range of applications while delivering higher performance levels. Valve manufactur ers continue their work in tweaking the various design elements contribut ing to pressure seal valve performance in order to provide greater value to the end user, thus assuring the key role that these valves will continue to play in power plant operation. VM This article was originally published by VMA and written by Don Bowers Jr. when he was the director of sales, power, at Velan. All images are copyright of Velan, and some of the technology described within may be proprietary to the com pany. Minor updates have been made for this republication.

Figure 17

Figure 18

them popular among piping system designers. 2. Tilting Disc Check (Figure 18). Due to a shorter moment between the hinge pin and centerline of the disc (vs. swing checks), tilting disc check valves can react quicker to reversals in flow, thus providing a higher margin of safety to the upstream equipment and media “hammer” potential. Note the differences in cost and Cv between these two common types of check valves before purchasing. 3. Piston Check (Figure 19). Pressure seal piston check valves are

frequently used in conjunction with globe-type isolation valves for reverse flow protection. These valves are some

Figure 19

NEW! HYDROGEN VALVE SUMMIT

Hydrogen Valve Summit: April 9, 2024 Valve Forum: Conference & Exhibits: April 10-11, 2024 Houston, Texas Mark your calendar now and plan to attend!

VALVE MAGAZINE SUMMER 2023 32

www.vma.org/valveforum