Steam turbine control valve for cyclic duty

Patent · Tue Jul 14 04:00:00 EDT 1987

OSTI ID:6332652

Dawawala, S K; La Coste, B L

This patent describes a turbine control valve comprising: a body having a cavity with an elongated generally round first opening on one side. The first opening has a circumferential sealing surface adjacent. A generally round second opening with a valve seat disposes on a side opposite the first opening, and a third opening for admitting steam to the cavity; a valve plug which mates with the valve seat to close off the second opening; a bonnet having a generally cylindrical portion with an integral flange on one end of the cylindrical portion, the flange has a circumferential seal surface which mates with the circumferential sealing surface adjacent the first opening; the bonnet has a centrally disposed bore extending with two counter bores inwardly from the end without the flange; the first counter bore is long and terminates with a large fillet radius; the second counter bore is sufficiently deep to receive the plug and also terminates with a fillet radius. The cylindrical portion has a first raised land on the outer surface adjacent the flange and a second raised land on the outer surface and spaced from the first land and the first raised land is larger in diameter than the second raised land. A plug guide is slidably disposed in the hardened sleeve and on the valve stem and affixed to the valve plug so that the sliding motion between the valve stem and the plug guide is small; the valve plug has a centrally disposed port extending which cooperates with the valve stem to provide means for reducing the force required to remove the plug from the seat to form a control valve operable for cyclic duty where large temperature changes occur at the plug.

• Assignee: Westinghouse Electric Corp., Pittsburgh, PA
• Patent Number(s): US 4679769
• OSTI ID: 6332652
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
421000* -- Engineering-- Combustion Systems
CLOSURES
CONTROL EQUIPMENT
EQUIPMENT
FLANGES
FLOW REGULATORS
MACHINERY
SEALS
STEAM TURBINES
TEMPERATURE EFFECTS
TURBINES
TURBOMACHINERY
VALVES