Section 9 Testing
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Offshore Units, July 2022 - Part 3 Functional Unit Types and Special Features - Chapter 12 Riser Systems - Section 9 Testing

Section 9 Testing

Parent topic: Chapter 12 Riser Systems

9.1 Hydrostatic testing

9.1.1 The requirements of Pt 3, Ch 12, 1.10 Equipment certification, 1.11 and 1.12 regarding certification and testing are to be complied with.

9.1.2  Steel risers:

  1. The riser system is to be hydrostatically tested after installation. Hydrostatic Testing Procedures are to comply with recognised international Codes and Standards.
  2. A written procedure is to be developed before hydrostatic testing commences. The acceptance criteria are to be agreed by LR.

9.1.3  Flexible risers. For flexible risers, pressure testing includes acceptance tests in the factory and hydrostatic test after installation. The acceptance test pressure should be in accordance with international Codes and Standards for flexible risers.

9.1.4 It is permissible to have pressure variations during a hydrostatic test provided they can be explained in terms of temperature changes and/or motions of the riser system.

9.1.5 In order to calculate the effect of temperature on pressure, it is essential that the temperature of the fluid in the pipe is measured and recorded at the same time as each pressure measurement is made and recorded. Ambient air or sea-water temperature are not relevant.

9.1.6 As a minimum, the temperature is to be measured near each end of the riser. Preferably at least one transducer on the sea bed part of the riser should also be provided.

9.1.7 Temperature sensors attached to the outside of the steel wall of a riser and insulated from the thermal effects of the sea are acceptable provided the test medium has been in the riser for at least 24 hours before the test is started, in order to allow the temperature of the fluid and steel to stabilise.

9.1.8 When conducting a hydrostatic test of a riser, the following requirements are to be complied with:
  1. The pressure (and temperature, if applicable) is to be continuously recorded for the duration of the test on a chart recorder.
  2. The chart is to be signed by the Surveyor at the beginning and end of the test.
  3. Pressure (and temperature, if applicable) readings are to be made at intervals not greater than 30 minutes and tabulated.
  4. Where temperature readings are to be taken the line is to be filled at least 24 hours before the test to enable the temperature to stabilise.
  5. The results of a hydrostatic test are to be recorded by a dossier containing the following:
    • Copies of all charts made during the test.
    • Copies of all tables of pressure readings (and temperature readings where applicable) made during the test.
    • Copies of calibration certificates for the pressure recorders used.
    • Calculations demonstrating temperature correction to pressure change where applicable.

9.1.9 The sections of riser are to be hydrostatically tested at the place of manufacture in accordance with Ch 6 Steel Pipes and Tubes of the Rules for Materials or the relevant National Standard.

9.1.10 Before a consent to start-up a riser can be given, evidence of a satisfactory hydrostatic test is to be provided. The evidence is to relate to a test completed during the 12 months prior to the date of application for the consent to start up.

9.2 Buckle detection

9.2.1 An adequate examination is to be carried out to determine that the completed riser is free from buckles, dents or similar damage.

9.3 Testing of communications, controls and safety systems

9.3.1 Communication systems, remote and automatic controls, emergency shut-down systems and other safety devices are to be tested in accordance with the approved test schedules required by Pt 3, Ch 12, 2.3 Plans and data to be submitted.

Copyright 2022 Clasifications Register Group Limited, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasifications Register Group Limited, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasifications Register'. Clasifications Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasifications Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.