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Hy-Drop Throttling Valves
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- MICROMETER DIAL assures accuracy of setting.
- STELLITE DISC with separate surfaces for shut-off and throttling. Resists galling, corrosion, erosion.
- HARD, CORROSION/EROSION RESISTANT SEAT.
- EXTRA DEEP, HIGH TEMPERATURE PACKING maintains tight seal, easy operation, protection from stem pitting.
- QUICK-CHANGE DISC-STEM ASSEMBLY can be converted on line from one orifice size to another.
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Yarway Hy-Drop Throttling Valves
| Valves used for throttling services have always been subject to rapid deterioration in the form of erosion, cavitation damage,
and wiredrawing of vital parts. Even venturi valves and other special configurations are vulnerable. The Hy-Drop Throttling Valve
embodies a unique concept, which so controls the destructive forces inherent in high pressure drop service that deterioration of
parts is virtually eliminated. Rapid energy dissipation is essential to the throttling process, and the Hy-Drop valve actually
encourages this at the same time containing its destructive capability. The basis for this concept is in the configuration of the
flow path as determined by the shape of the valve disc and seat. Fluid flowing through the annulus between disc and cylindrical
seat accelerates smoothly until it reaches the blunt end of the disc. At this point, the flow area increases abruptly at its center
and the resulting pressure drop at the core of the flow path causes rapid expansion of the fluid toward the core. Thus, the essential
vaporization and turbulence occur at the center, within a layer of unvaporized fluid which continues to flow along and protect
the sleeve wall. With this configuration, the vaporization process is so efficient that the vapor formed is momentarily supersaturated
and the remaining liquid subcooled, until equilibrium is reestablished a short distance down the sleeve passage. |
Applications
The Hy-Drop Throttling Valve is designed for continuous blowdown, but also works well for sampling, high pressure vents, boiler
feed pump bypass relief, high pressure drop services associated with erosive and wiredrawing characteristics–or where velocity
is sufficient to destroy valves of conventional globe or even venturi designs.
Advantages
- Stellite Seat: Gives the extra advantage of resisting corrosion and wiredrawing
- Guided Disc: The Hy-Drop Valve’s guided disc assures constancy of the valve setting by eliminating the non-uniform flow pattern
caused by disc vibration and chatter
- Loose Disc: Disc design provides multi-position seating and assures positive alignment of seat and disc surfaces. This gives
sure protection against premature failures from seat-to-disc "grind" prevalent in valves of integral stem-disc design
- Dual-Purpose Disc: Stellite Disc has separate surfaces for shutoff and throttling. This eliminates the need for a supplementary
valve for shutoff service
- Quick-Change Disc: Now you can convert your valve to meet a change in plant cycle conditions, without removing it from the
line. Simply insert an interchangeable stem-disc into the same valve body to convert from one orifice size to another. All
Yarway Hy-Drop Valves have a passage equivalent to either a 5/8" or a 1" orifice, depending upon valve body ordered. The annular
orifice, or specified orifice size, is governed not by varying the passage opening but by varying the size of the throttling
disc. Calibrated discs are available for each orifice range
- Resetting Capability: the Hy-Drop Valve has positive resetting capability to accommodate multiple-operation programs with
accurate flow control variations
- In-Line Repair: Yarway reseating tool can be used to cut a new seat without removing the valve from the piping.
- Motor Actuation: For local or remote operation
- Pneumatic Actuation: For automatic control
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Features and Benefits
- Dual Range Throttling – primary range plus a super capacity blast range.
- Rapid energy dissipation – controls the destructive forces inherent in high pressure drop service.
- Accurate and repeatable settings – micrometer dial assures setting accuracy and positive resetting capability.
- Quick-change disc – insert an interchangeable stem-disc into the same valve body to convert from one orifice
size to another.
- Guided-disc – eliminates disc vibration and chatter.
- Dual-purpose disc – separate surfaces for shutoff and throttling.
- Stellite seat – resists corrosion and wiredrawing.
- In-line repair – Yarway reseating tool can be used to cut a new seat in-line.
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