Small Yarway Globe Valves - SealOE
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Small Yarway Globe Valves
Problem
Yarway Model 5500 small globe valves have an extremely large packing cross-section due to their bonnet-less design. This typically requires a compromise of either ease of cycling or leak-free service. The standard packing set for small Yarway globe valves includes a six ring set yielding an expected packing drag of ~960 lbf under 4,000 psi packing stress. A reengineered packing set will decrease stem friction while maintaining sealability.
Solution
To decrease stem friction use two reduced-height graphite rings as your primary sealing components. Two composite graphite end rings will drastically reduce stem friction compared to their graphitic yarn counterparts. To occupy the remaining space within the large stuffing box, install a 0.063” graphite washer and a hardened carbon bushing in the bottom of the stuffing box. The reduction in the number of sealing rings and the use of composite graphite end rings reduces the expected packing drag to ~250 lbf without compromising sealability.
Old packing configuration: YGGGGY
Y – Graphitic yarn wiper rings
G – Standard height graphite sealing rings
Reengineered packing configuration: CGGCBW
C – Composite rings
G – Reduced height graphite sealing rings
B – Carbon Bushing
W – Style 6200N Graphite washer
