Dynaflow Ball Valves, Specialty & Ball Valve Engineering: Special Features

SPECIAL FEATURES OF DYNAFLOW VALVES

A. NOTES:
Male thread on gland has heat cured solid film lubricant to eliminate galling on stainless steel valves.
B.COMPLETELY TOP LOADED
Allows complete disassembly without removing valve from line.
Facilitates maintenance and reduces number of pressure boundary parts due to threaded gland.
C. LEAKPROOF VALVE STEM
Teflon foot seal keeps static seal ring from contacting stem eliminating wear.
D. SEPARATED BALL AND STEM
Assumes alignment of ball and seat, eliminates shaft seal leakage and stem galling normally caused by ball shifting when subjected to pressure surges or pressure reversals. Separated ball and stem insures ball and seat alignment by divorcing vertical load on stem.
E. HYDRODYNAMICALLY ENGERIZED SEAL
Single seat provides bi-directional sealing with minimum seat loading for positive sealing in direct proportion to line pressure.
F. BELLEVILLE SPRING
Provides initial seat loading for low pressure sealing.
G. BEARING SUPPORTED BALL
Heavy loads on ball carried by integral trunnions supported in low friction sleeve bearings, permitting sealing seat to be optimized for perfect sealing.

SEALING CHARACTERISTICS OF DYNAFLOW VALVES

The dynaflow seal is pressure energized which results in bubble tight sealing under all pressure conditions. The single seal operates effectively against pressure differentials in either direction. The sealing force is determined by line pressure - the higher the pressure, the greater the sealing force. Initial sealing force results from compressing a belleville spring. Seal areas are carefully controlled to prevent excessive loading of the seat. Relaxation of the belleville spring compensates for seat water.

Unbalanced sealing areas create a resultant force of seat against ball, increasing seat force against the ball. The effective sealing diameter of the static seal is at its outside diameter and the dynamic seal diameter creates a controlled force against the ball. Unbalanced sealing areas create a resultant force of seat against ball, increasing seat force against the ball. The effective sealing diameter of the static seal is at its inside diameter, and thus there is an annular area subjected to the higher pressure.

SEALING CHARACTERISTICS OF DYNAFLOW VALVES

The dynaflow seal is pressure energized which results in bubble tight sealing under all pressure conditions. The single seal operates effectively against pressure differentials in either direction. The sealing force is determined by line pressure - the higher the pressure, the greater the sealing force.		Initial sealing force results from compressing a belleville spring. Seal areas are carefully controlled to prevent excessive loading of the seat. Relaxation of the belleville spring compensates for seat water.

Unbalanced sealing areas create a resultant force of seat against ball, increasing seat force against the ball. The effective sealing diameter of the static seal is at its outside diameter and the dynamic seal diameter creates a controlled force against the ball.		Unbalanced sealing areas create a resultant force of seat against ball, increasing seat force against the ball. The effective sealing diameter of the static seal is at its inside diameter, and thus there is an annular area subjected to the higher pressure.