Woodward Over Speed Protection for Steam Turbines

TG611, TG Governor with Overspeed Protection

Directly replaces TG Governors
API 611* Compliant Overspeed Testing

Easily overspeed test your steam turbine using the new Woodward TG611 governor with integral overspeed test device.

TG611 Governors are self-contained, mechanical-hydraulic, speed-droop governors for use on small steam turbines driving pumps, compressors, or generators, where isochronous (constant speed) operation is not required. These governors are directly coupled to the steam-turbine’s rotor or auxiliary shaft to sense and control turbine speed.

Designed for API-611-based turbine applications, these governors include a special Overspeed Test Device, allowing controlled and safe turbine overspeed trip testing.

TG Exchanges and Conversions

TG Tach Kit

*API STANDARD 611, Fifth Edition, March 2008, Paragraph 7.4.2.2.11 states: "Unless otherwise specified, the oil relay governor shall include a manual method to safely increase the speed of the turbine over the maximum continuous speed of the governor to allow for a safe and controlled test of the independent emergency overspeed system. This system shall be arranged that releasing of the device shall allow the turbine to return to maximum continuous speed with no further operator action. This device shall not allow the turbine to exceed the trip setting by 2%."

Features

Simplicity and low cost are distinct advantages of the TG611 Governor. It includes an integral overspeed test device that allows the speed to be safely increased in a controlled manner up to the turbine’s overspeed trip speed. This feature allows for testing of the turbine’s overspeed trip mechanism in a safe manner.

The governor operates with speed droop for stability of control and screw-type speed setting. An internal oil pump, driven by the governor's drive shaft, transports oil from the self-contained sump. Internal pressure is maintained by a relief valve-accumulator system. An oil sight-glass provides ease in checking the oil level. The output (terminal) shaft extends out both sides of the case, and the governor drive rotation can be in either direction.

The built-in relief valve-accumulator helps maintain full oil pressure in the governor hydraulic system during transient conditions. Contamination is reduced by the weatherproof construction and the self-contained oil sump.

How the TG611 Works

Woodward’s new TG611 is exactly like your present TG governor, but with built-in overspeed test capabilities that meet the API 611 requirements. The TG611 is:

• field adjustable for overspeed test speed
• allows testing from any speed setting
• easy to use:

• remove the overspeed test device cap
• insert the cap’s dowel pin into the cam
• rotate it like a lever to increase the speed to its overspeed trip
• maintains governor control during overspeed testing
• releasing the cam at any time during the test causes the TG611 to immediately return to its normal speed setting.

Ask for the TG611 for your next new or replacement TG unit and how your existing TG unit can be upgraded into a TG611.

Contact GCS for product specifications and technical manuals