oSIST prEN IEC 60953-4:2025

SLOVENSKI STANDARD
01-oktober-2025
Pravila za preskuse toplotne sprejemljivosti parne turbine - 4. del: Rutinsko
preskušanje
Rules for steam turbine thermal acceptance tests - Part 4: Routine testing
Ta slovenski standard je istoveten z: prEN IEC 60953-4:2025
ICS:
27.040 Plinske in parne turbine. Gas and steam turbines.
Parni stroji Steam engines
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

5/282/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
Project number:
IEC 60953-4 ED1
Date of circulation: Closing date for voting:
2025-08-29 2025-11-21
Supersedes documents:
5/279/CD, 5/281A/CC
IEC TC 5 : Steam turbines
Secretariat: Secretary:
China Mr Chang Fu
Of interest to the following committees: Horizontal function(s):

Aspects concerned:
Energy Efficiency
Submitted for CENELEC parallel voting Not submitted for CENELEC parallel voting
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Title:
Rules for steam turbine thermal acceptance tests - Part 4: Routine testing

proposed stability date: 2035
Note from TC/SC officers:
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
permission in writing from IEC.

IEC CDV 60953-4 ED1 © IEC 2025

1 CONTENTS
2 FOREWORD . 8
3 INTRODUCTION . 10
4 1 Scope . 12
5 1.1 General . 12
6 1.2 Object . 12
7 2 Normative references . 13
8 3 Units, symbols, terms and definitions . 13
9 3.1 General . 13
10 3.2 Symbols, units . 13
11 3.3 Subscripts, superscripts and definitions . 13
12 3.3.1 Reference condition . 13
13 3.3.2 Reference test . 13
14 3.3.3 Comparative test . 13
15 3.3.4 Repeatability . 14
16 3.3.5 Primary parameters . 14
17 3.3.6 Secondary parameters . 14
18 3.4 Definition of routine test results . 14
19 3.4.1 Guidance on routine performance parameters . 14
20 3.4.2 Thermal efficiency . 14
21 3.4.3 Heat rate . 14
22 3.4.4 Thermodynamic efficiency . 14
23 3.4.5 Steam rate . 14
24 3.4.6 Main steam flow capacity . 14
25 3.4.7 Power output . 14
26 3.4.8 Guarantee values for extraction and mixed-pressure turbines . 14
27 3.4.9 Thermal Load Capacity (for Nuclear applications) . 15
28 3.5 Additional definition of routine test results . 15
29 3.5.1 Turbine efficiency -Expansion in superheated region . 15
30 3.5.2 Turbine stage flow factor . 15
31 3.5.3 Corrected Turbine stage pressures . 16
32 3.5.4 Heat rate and power output characteristic . 17
33 3.5.5 Heat input and power output characteristic . 17
34 3.5.6 Component performance . 17
35 4 Guiding principles . 19
36 4.1 Advance planning for test. 19
37 4.2 Preparatory agreements and arrangements for tests . 19
38 4.3 Planning for test. 19
39 4.3.1 Time for routine test . 19
40 4.3.2 Direction of routine tests . 20
41 4.4 Preparation of the tests . 20
42 4.4.1 Condition of the plant . 20
43 4.4.2 Condition of the steam turbine . 20
44 4.4.3 Condition of the condenser . 20
45 4.4.4 Isolation of the cycle . 21
46 4.4.5 Checks for leakage of condenser and feed water heaters . 21
47 4.4.6 Cleanliness of the steam strainers . 21
48 4.4.7 Checking of the test measuring equipment . 21
IEC CDV 60953-4 ED1 © IEC 2025

49 4.5 Comparison measurements . 21
50 4.6 Settings for tests . 22
51 4.6.1 Load settings . 22
52 4.6.2 Special settings . 22
53 4.7 Preliminary tests . 22
54 4.8 Acceptance tests . 22
55 4.8.1 Constancy of test conditions . 22
56 4.8.2 Maximum deviation and fluctuation in test conditions . 22
57 4.8.3 Duration of test runs and frequency of reading. 22
58 4.8.4 Reading of integrating measuring instruments . 22
59 4.8.5 Alternative methods . 22
60 4.8.6 Recording of tests . 22
61 4.8.7 Additional measurement . 22
62 4.8.8 Preliminary calculations . 22
63 4.8.9 Consistency and number of tests . 22
64 4.9 Repetition of Acceptance tests . 23
65 5 Measuring techniques and measuring instruments . 23
66 5.1 Overview . 23
67 5.1.1 Instrument accuracy requirements . 23
68 5.1.2 Measuring instruments . 23
69 5.1.3 Measuring uncertainty . 23
70 5.1.4 Calibration of instruments . 23
71 5.1.5 Alternative instrumentation . 23
72 5.1.6 Consistency of comparative test instruments . 23
73 5.1.7 Special considerations of permanently installed instrument . 24
74 5.2 Measurement of power. 25
75 5.2.1 Determination of mechanical turbine output . 25
76 5.2.2 Measurement of boiler feed pump power . 25
77 5.2.3 Determination of electrical power of a turbine generator . 25
78 5.2.4 Measurement of electrical power . 25
79 5.2.5 Electrical instrument connections. 25
80 5.2.6 Electrical instruments . 25
81 5.2.7 Instrument transformers . 25
82 5.3 Flow measurement . 25
83 5.3.1 Determination of flows to be measured . 25
84 5.3.2 Measurement of primary flow . 29
85 5.3.3 Installation and location of flow measuring devices . 29
86 5.3.4 Calibration of primary flow devices for water flow . 29
87 5.3.5 Inspection of flow measuring devices . 30
88 5.3.6 Differential pressure measurements . 30
89 5.3.7 Water flow fluctuation . 30
90 5.3.8 Secondary flow measurements . 30
91 5.3.9 Occasional secondary flows. 31
92 5.3.10 Density of water and steam . 31
93 5.3.11 Determination of cooling water flow of condenser . 31
94 5.4 Pressure measurement (excluding condensing turbine exhaust pressure) . 31
95 5.4.1 Pressures to be measured . 31
96 5.4.2 Instruments . 32
97 5.4.3 Main pressure measurements . 32
IEC CDV 60953-4 ED1 © IEC 2025

98 5.4.4 Pressure tapping holes and connecting lines . 32
99 5.4.5 Shut-off valves . 32
100 5.4.6 Calibration of pressure measuring devices . 32
101 5.4.7 Atmospheric pressure . 33
102 5.4.8 Correction of readings . 33
103 5.5 Condensing turbine exhaust pressure measurement . 33
104 5.5.1 General .
...