Description

The Woodward TG-13/TG-17 and TG611-13/TG611-17 are mechanical-hydraulic speed droop governors for controlling steam turbines—applications where isochronous (constant-speed) operation is not required.

The TG-13/TG-17 and TG611-13/TG611-17 governors have a full 40 degrees of maximum terminal-shaft travel. Recommended travel from the no load to the full load position is 2/3 of full governor travel.

See Figure 1-1 for a graphic representation of maximum work capacity for the governors and related governor terminal shaft travel information.

Maximum work capacity over full governor travel of 40° is 12.2 ft-lb (16.5 J) for the   TG-13/TG611-13 and 17.5 ft-lb (23.7 J) for the TG-17/TG611-17. See above for recommended governor output travel. In special applications, min and max prime mover stops may be outside the governor stops.

Governor output is provided through a serrated terminal shaft extending from both sides of the case.

The internal pump for the governors is sized to operate over standard speed ranges: 

 • 1100 to 2400 rpm 

 • 2400 to 4000 rpm 

 • 4000 to 6000 rpm

The TG-13/TG611-13 governor operates with 1034 kPa (150 psi) internal oil pressure, and the TG 17/TG611-17 operates with 1379 kPa (200 psi) internal oil pressure.

Either governor is set to the speed range specified by the customer at time of order. The high-speed governor (4000 to 6000 rpm) may require a heat exchanger in some applications (see end of Chapter 2, “When is a Heat Exchanger Necessary?”). Both governors are capable of controlling at lower-than specified speed range with some loss of output torque and performance. The governor should not be run at a speed greater than the range specified because of heat rise and component wear issues.

The governors are available with either a cast-iron case or a die-cast aluminum case.

Speed droop is required for stable governor operation. Droop is factory set, but internally adjustable.

Two means of speed setting are available. Screw speed setting is standard. Lever speed setting is optional and provided by a serrated shaft assembly extending from both sides of the cover.

The TG-13 and TG-17 governors are identified as either a screw speed-setting or as a lever speed-setting governor. The TG611 governors are screw speed-setting only (see Figure 1-2).

Governor drive shaft rotation for both governors is single direction only. In both the cast iron and the die cast aluminum governors, rotation can be changed in the field. In the cast iron governor, it must be changed internally, and in the die-cast aluminum governor, it can be changed externally by removing four screws and rotating the pump housing 180 degrees (see Chapter 2).

Governor maintenance is minimal due to few moving parts, weatherproof design, and self-contained oil supply. The governor drive shaft operates a gerotor oil pump. Internal oil pump pressure is regulated by a relief valve/accumulator. The oil sight gauge installed on each side of the governor case makes oil condition and oil-level checking simple.

Introduction

Use care while handling and installing the TG-13/TG-17 and TG611-13/ TG611-17 governors. Be particularly careful to avoid striking the drive shaft, terminal shafts, speed setting shafts, or adjusting screw. Abuse can damage seals, internal parts, and factory adjustments.

Do not rest the governor on its drive shaft.

Explosion Hazard

—The surface temperature of this governor depends on three operating conditions: drive shaft speed, ambient temperature, and hydraulic fluid selection. It is the user's responsibility to maintain a safe surface and fluid temperature. If normal operating conditions cause the surface temperature of the TG to rise close to ignition temperatures of hazardous gases in the external environment or near the maximum recommended hydraulic fluid temperature, a heat exchanger must be installed. Refer to the sections on “Heat Exchanger Installation” and “When is a Heat Exchanger Necessary?” for location and sizing of the ports for connection of a heat exchanger.

Explosion Hazard—External fire protection is not provided in the scope of this product. It is the responsibility of the user to satisfy any applicable requirements for their system.

Due to typical noise levels in turbine environments, hearing protection should be worn when working on or around the TG governor.

The surface of this product can become hot enough to be a hazard. Use protective gear for product handling in these circumstances.

Receiving

The governor is shipped from the factory bolted to a wooden platform in the vertical position and boxed. An oil sight gauge is factory installed on each side of the case, and a breather/filler cap is positioned for vertical governor mounting and operation.

After factory testing and adjusting, the governor is drained of oil, sealed, and painted. A light film of oil covers internal parts to prevent rust. External shafts are coated with a spray lubricant. No internal cleaning or flushing is necessary before installation and operation or customer retesting.

Storage

The governor may be stored for short periods of time as received from the factory. For long-term storage, storage in a hostile environment (large temperature changes, humid or corrosive atmosphere), or if the governor is installed on the turbine for storage, fill the governor with oil and follow preservation packaging instructions in Woodward Manual 25075, Commercial Preservation Packaging for Storage of Mechanical Hydraulic Controls.

If the breather/filler cap has been moved for horizontal governor operation and the governor is to be stored vertically, replace the cap with a plug before filling the governor with oil to prevent oil from draining through the cap.

Drive-Shaft Rotation

Governor drive-shaft rotation is determined by looking at the governor from the top.

The correct direction of rotation of the TG, when viewed from the top of the governor, is stamped “cw” (clockwise) or “ccw” (counterclockwise) on the governor nameplate.

Governor drive-shaft rotation is single direction only. When looking at the governor from the top, the direction of rotation must be the same as the turbine-shaft rotation when looking at the mounting pad.

If the governor oil pump is rotated in the wrong direction, the governor will not have oil pressure. Without oil pressure, pump parts start heating up, which can result in possible seizure of rotating parts.

Be sure governor-drive and turbine-drive rotation is the same when looking at the governor and the mounting pad from the top. Incorrect drive rotation may cause governor damage