ASME TDP-1–2013

(Revision of ASME TDP-1–2006)

Prevention of Water
Damage to Steam
Turbines Used for
Electric Power
Generation:
Fossil-Fueled Plants

A N A M E R I C A N N AT I O N A L STA N DA R D

Copyright c 2013 by the American Society of Mechanical Engineers.

No reproduction may be made of this material without written consent of ASME.
 Copyright c 2013 by the American Society of Mechanical Engineers.
No reproduction may be made of this material without written consent of ASME.
 ASME TDP-1–2013
(Revision of ASME TDP-1–2006)

Prevention of Water
Damage to Steam
Turbines Used for
Electric Power
Generation:
Fossil-Fueled Plants

A N A M E R I C A N N AT I O N A L S TA N D A R D

Two Park Avenue • New York, NY • 10016 USA

Copyright c 2013 by the American Society of Mechanical Engineers.

No reproduction may be made of this material without written consent of ASME.
 Date of Issuance: June 7, 2013

This Standard will be revised when the Society approves the issuance of a new edition.

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Copyright c 2013 by the American Society of Mechanical Engineers.

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 CONTENTS

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
Committee Roster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3 Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5 Testing, Inspection, Maintenance, and Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
6 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Figures
1 Typical Flash Tank/Separators Arrangement: Local Control System . . . . . . . . . . . . . . . . . . 6
2 Typical Flash Tank/Separators Arrangement: Integrated Control System . . . . . . . . . . . . . 7
3 Typical Leveling System Arrangement: Integrated Control System . . . . . . . . . . . . . . . . . . . 8
4 Typical Attemperator System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Typical Drain System With Redundant Level Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6 Typical Heater Steam Side Isolation System: Local Control System . . . . . . . . . . . . . . . . . . 14
7 Typical Heater Steam Side Isolation System: Integrated Control System . . . . . . . . . . . . . 15
8 Typical Heater Tube Side Isolation System: Local Control System . . . . . . . . . . . . . . . . . . . 16
9 Typical Heater Tube Side Isolation System: Integrated Control System . . . . . . . . . . . . . . . 17
10 Typical Deaerator Arrangement With Drain System: Local Control System . . . . . . . . . . . 19
11 Typical Deaerator Arrangement With Drain System: Integrated Control System . . . . . . 20
12 Typical Deaerator Arrangement With Inlet Isolation: Local Control System . . . . . . . . . . 21
13 Typical Deaerator Arrangement With Inlet Isolation: Integrated Control System . . . . . . 22
14 Main Turbine: Typical Steam Seal Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Tables
1 Symbol Legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Device Identification Letters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

iii
Copyright c 2013 by the American Society of Mechanical Engineers.
No reproduction may be made of this material without written consent of ASME.
 FOREWORD

In the late 1960s, a substantial increase in the number of reported occurrences of steam turbine
damage by water induction precipitated design recommendations from the two major U.S. steam
turbine manufacturers in an attempt to reduce such incidents. Consequently, utilities and designers
began formulating their own design criteria because of the economic need to keep the generating
units in service. Realizing the common need for a uniform set of design criteria to alleviate this
problem, an American Society of Mechanical Engineers (ASME) Standards Committee was formed,
consisting of representatives of utilities, equipment manufacturers, and design consultants to
develop recommended practices for use in the electric generating industry.
This Standard, resulting from the work and deliberation of the Turbine Water Damage
Prevention Committee, was approved as a Standard of The American Society of Mechanical
Engineers by the ASME Standardization Committee and the ASME Policy Board, Codes and
Standards, on July 26, 1972.
In 1979, the Committee proposed a revision to this Standard to include information on condenser
steam and water dumps, direct contact feedwater heaters, and steam generators. This proposed
revision was approved by the ASME Standardization Committee on April 25, 1980.
The 1985 revision was approved as an American National Standard on September 13, 1985. In
1994, the ASME Board on Standardization approved the disbandment of the Committee on
Turbine Water Damage Prevention along with the withdrawal of the standard TDP-1. This was
due to perceived lack of interest and use by the industry.
Subsequent interest from users and potential users for TDP-1 convinced ASME to reconstitute
the Committee under the Board on Pressure Technology Codes and Standards in June 1997. As
a result of this committee’s work, TDP-1–1985 was revised and approved as an American National
Standard on June 17, 1998.
Advances in power plant technology, most notably combined cycle, multiple steam generators,
cycling, cogeneration technology, and modern plant instrumentation and control systems, con-
vinced the Committee to again revise the Standard. The result was TDP-1–2006. This revision
was approved as an American National Standard on November 6, 2006.
The current Standard is a revision of TDP-1–2006. The broad acceptance that this Standard has
received caused ASME to decide to reissue it in mandatory language rather than a recommended
practice. In addition to the change to mandatory language, this revision also includes minor
modifications and clarifications to the previous revision. This revision was approved as an
American National Standard on February 5, 2013.

iv
Copyright c 2013 by the American Society of Mechanical Engineers.
No reproduction may be made of this material without written consent of ASME.
 ASME TWDP COMMITTEE
Turbine Water Damage Prevention
(The following is the roster of the Committee at the time of approval of this Standard.)

STANDARDS COMMITTEE OFFICERS

L. A. Kielasa, Chair
R. G. Narula, Vice Chair
T. W. Schellens, Secretary

STANDARDS COMMITTEE PERSONNEL

J. C. Boyle, FM Global
A. Atoui, Alternate, FM Global
V. C. Buquoi, Siemens Power Generation, Inc.
M. Heue, Alternate, Siemens Power Generation, Inc.
A. M. Donaldson, WorleyParsons
J. C. Archer, Alternate, WorleyParsons
G. W. Doody, Nuclear Service Organization, Inc.
G. M. Golden, Consultant
L. A. Kielasa, Detroit Edison Co.
R. A. Masten, Sargent & Lundy
R. G. Narula, Consultant
D. D. Reed, Dominion Generation
T. W. Schellens, The American Society of Mechanical Engineers
D. W. Schottler, Xcel Energy
J. J. Shutt, Cygnature Consulting, LLC
J. Steverman, Jr., Steverman Engineering, LLC
M. Wiernicki, ITAC
W. C. Wood, Duke Energy
S. I. Hogg, Contributing Member, University of Durham

v
Copyright c 2013 by the American Society of Mechanical Engineers.
No reproduction may be made of this material without written consent of ASME.
 INTENTIONALLY LEFT BLANK

vi
Copyright c 2013 by the American Society of Mechanical Engineers.
No reproduction may be made of this material without written consent of ASME.
 ASME TDP-1–2013

PREVENTION OF WATER DAMAGE TO STEAM TURBINES USED

FOR ELECTRIC POWER GENERATION: FOSSIL-FUELED PLANTS

1 SCOPE 2.1.2 However, since malfunctions do occur, imple-

ment one or more of the following steps to prevent
This Standard includes recommended practices con-
turbine damage due to water induction:
cerned primarily with the prevention of water damage
(a) detect the presence of water either in the turbine
to steam turbines used for fossil-fuel-fired electric power
generation. The practices address damage due to water, or, preferably, external to the turbine before the water
wet steam, and steam backflow into a steam turbine. has caused damage
The practices are applicable to conventional steam cycle, (b) isolate the water by manual or, preferably, auto-
combined cycle, and cogeneration plants. The practices matic means after it has been detected
cover design, operation, inspection, testing, and mainte- (c) dispose of the water by either manual or, prefera-
nance of those aspects of the following power plant bly, automatic means after it has been detected
systems and equipment concerned with preventing the
induction of water into steam turbines: 2.1.3 No single failure of equipment, device, or
(a) motive steam systems signal, or loss of electrical power, shall result in water
(b) steam attemperation systems or cold steam entering the turbine.
(c) turbine extraction/admission systems
2.1.4 Steam lines connecting to the steam turbine
(d) feedwater heaters directly or indirectly shall be designed to ensure that any
(e) turbine drain system saturated steam or condensate that may have collected
(f) turbine steam seal system while the line or portion of the line was out of service
(g) start-up systems is drained and warmed adequately prior to being
(h) condenser steam and water dumps returned to service.
(i) steam generator sources
Any connection to the turbine is a potential source of 2.1.5 Any automatic control system used to control
water either by induction from external equipment or by steam line drain valves identified in these guidelines
accumulation of condensed steam. The sources treated shall be designed so that the system has a means of
herein specifically are those found to be most frequently initiating automatic valve actuation and a separate
involved in causing damage to turbines. Although water means of verifying the appropriateness of the automatic
induction into the high and intermediate pressure tur- action. For example, if a drain valve is closed automati-
bines has historically been recognized as the most dam- cally based on a timer, something other than the timer,
aging, experience has shown that water induction in such as a level switch that would alarm if water were
low pressure turbines can cause significant damage and still present in the steam line, shall be used to verify that
should also be taken seriously. the timer initiation was appropriate. If an inappropriate
This Standard is not intended to impose new require- action is taken, an alarm shall be provided.
ments retroactively for existing facilities.
2.1.6 An integrated control system (ICS) such as
a distributed control system (DCS) can, by its inherent
2 CRITERIA design, provide additional control and monitoring capa-
2.1 Basis bility for power plant systems and equipment. Use of
an ICS has been considered as an option for control and
2.1.1 The normal practice to prevent turbine water monitoring potential sources that might allow water to
induction is to enter the turbine. If an ICS is available, the additional
(a) identify systems that have a potential to allow redundancy and availability of that system shall be used
water to enter the turbine as indicated in this Standard. However, if no ICS is
(b) design, control, maintain, test, and operate these provided, following the non-ICS specific requirements
systems in a manner that prevents accumulation of is intended to still represent a conservative design for
water protection from water induction.

1
Copyright c 2013 by the American Society of Mechanical Engineers.
No reproduction may be made of this material without written consent of ASME.