ASME PTC 20.1

Description / Abstract: OBJECT AND SCOPE

The purposes of this Code are:

To establish test procedures for determining performance characteristics of speed and load governing systems applicable to the equipment covered under this Code. These performance characteristics include:

(1) Adjustable Speed Functions

(a) Speed/Load Changer Minimum Speed Holding Level

(b) Other Speed Holding Levels

(c) Acceleration Control

(d) Speed/Load Changer Low Speed Limit

(e) Speed/Load Changer High Speed Limit

(f) Synchronizing Speed Range

(g) Maximum Speed at Rated Power

(2) Speed-State Speed Regulation

(3) Steady-State Incremental Speed Regulation

(4) Dead Band

(5) Steady-State Governing Speed Band

(6) Steady-State Governing Load Band

(7) Response and Settling Time

(8) Overspeed

(9) Speed/Load Changer Governing System Reference Reducing Time

To establish a format and procedures for describing the system performance by means of the test quantities obtained under Par. 1.01.

This Code is applicable to the testing of speed and load governing systems for steam turbine-generator units with the steam turbines classified as follows:

(a) Straight condensing, straight noncondensing and regenerative turbines without initial and/or exhaust steam pressure control, including reheat turbines.

(b) Straight condensing, straight noncondensing and regenerative turbines with initial and/or exhaust steam pressure control, including reheat turbines.

(c) Automatic extraction and mixed-pressure turbines, in conjunction with PTC 20.3, Pressure Control Systems Used on Steam Turbine-Generator Units.