DL/T 5071-2012 in English

Manufacturing process guide for the field assembly of Francis turbine runner

1 General provisions

1.0.1 This guide is formulated for the purpose to standardize the technological methods, technical requirements, operating procedures and inspection of Francis turbine runner in field assembly, welding, heat treatment and machining.

1.0.2 This guide is applicable to the whole manufacture of martensitic stainless steel Francis runner on site, and may also serve as a reference for other runners manufactured on site.

1.0.3 This guide is revised according to the requirements of relevant regulations and specifications, combined with the actual construction experience and technological methods of project.

1.0.4 Before the runner is assembled on the construction site, its parts shall be subject to inspection and acceptance according to the requirements of JB/T 8660 Packaging, transportation and storage specifications of hydroelectric generating unit and relevant clauses of the contract. Only the equipment that passes the inspection and acceptance can be assembled.

1.0.5 The manufacture of Francis turbine runner on site shall comply with the current national standards and specifications in addition to this guide.

2 Construction field

2.1 Requirements of the split runner part assembly and welding field

2.1.1 The split runner part assembly and welding field is generally arranged in the installation room of hydropower plant powerhouse, and shall have sufficient bearing capacity.

2.1.2 The room temperature of the runner manufacturing workshop shall not be lower than 5°C and the relative humidity shall not be greater than 75%. The direct blowing of air flow on the runner and its welds shall be avoided.

2.1.3 The runner manufacturing field shall have reliable compressed air, water, power supply and firefighting facilities.

 
2.1.4 The buttress setting of split runner assembly and welding station shall meet the following requirements:

1 As shown in Figure 2.1.4, six buttresses are set for runner welding, with the height of generally 750 mm. The buttress shall be firmly set and connected with section steel, and the top surface shall be flat.


2 The size of the wedge plate used for runner leveling shall be adjusted. It shall be determined according to the stress on the contact surface not greater than 10 MPa, the overlapping length of the wedge plate shall account for more than 2/3 of the total length, and the relative height difference of the top surface of each wedge plate shall not be greater than 1 mm. The wedge plate may be fixed by spot welding temporarily in order to prevent the wedge plate from sliding when lifting the runner.

2.2 Planning and design of the runner segments part manufacture workshop

2.2.1 A special runner manufacturing workshop shall be built on the site of the power plant, which shall be determined according to the main technical parameters, technology and production scale of the runner, and shall be planned and designed with reference to the relevant conditions on the site. One assembly, welding, heat treatment and processing station is generally set in the workshop, and one station may be shared for runner turning, grinding and static balance. The assembly and welding stations may be appropriately added according to the manufacturing quantity and delivery schedule of runners of the power station.

Foreword i
1 General provisions
2 Construction field
2.1 Requirements of the split runner part assembly and welding field
2.2 Planning and design of the runner segments part manufacture workshop
2.3 Requested technology documents of runner parts field assembly
3 Runner parts assembly
3.1 Assembly technology of split runner
3.2 Assembly technology of runner segments parts
4 Runner welding
4.1 Runner welder
4.2 Welding technology of split runner
4.3 Welding technology of runner segments parts
5 Heat treatment of runner
5.1 Weld local heat treatment of split runner
5.2 Heat treatment technology of whole runner
6 Non-destructive testing (NDT)
6.1 Qualification of NDT personnel and equipment
6.2 Period of NDT
6.3 NDT of welds
6.4 Repair of defect
6.5 NDT report
7 Runner grinding
7.1 General requirements of runner grinding
7.2 Grinding process
8 Runner machining
9 Static balance of runner
10 Residual stress test of runner
10.1 Test method of residual stress
10.2 General requirements of residual stress test
Explanation of wording in this specification
List of quoted standards