SL/T 153-1995 Technical Specification for Low-pressure Pipeline Water Supply Irrigation Project (Part of Well Irrigation Area) SL/T 153-95
Some standard content:
Industry Standard of the People's Republic of China
Technical Specification for Low-Pressure Pipeline Water Irrigation Project (Part for Well Irrigation Area)
SL/T153--95
Editor: China Institute of Water Resources and Hydropower ResearchApproving Department: Ministry of Water Resources of the People's Republic of ChinaEffective Date: July 1, 1995
SL/T153-95
Ministry of Water Resources of the People's Republic of China
Notice on Approval of Issuance of "Technical Specification for Low-Pressure Pipeline Water Irrigation Project (Part for Well Irrigation Area)" (SL/T153-95)Shui Ke Jiao [1995] No. 97
According to the 1991 plan for the formulation and revision of water conservancy and hydropower technical standards, the "Technical Specification for Low-Pressure Pipeline Water Irrigation Project (Part for Irrigation Area)" was formulated under the auspices of the Ministry's Science and Technology Department and edited by the China Institute of Water Resources and Hydropower Research. It has been reviewed and approved as a water conservancy industry standard and has been promulgated. The name and number of the standard are: "Technical Specifications for Low-pressure Pipeline Water Transport Irrigation Projects (Part of Well Irrigation Areas)" SL/T153-95. This standard shall be implemented from July 1, 1995. During the implementation process, all units shall pay attention to summarizing experience. If there are any problems, please inform the Ministry's Science and Technology Department, which will be responsible for interpretation. The standard text is published and distributed by China Water Resources and Hydropower Press. March 27, 1995
Project planning
Project design
Water pump selection and matching
Pipes and fittings
Accessory equipmentWww.bzxZ.net
Project construction and equipment installation
Project acceptance
9 Operation and maintenance
Appendix A Terms and symbols
Appendix B
Calculation of radial deformation of pipelines
Additional instructions
Clause explanation
Irrigation of shallow drainage lanes·Water-saving irrigation
...........
SL/T153—95
1 General provisions
1.0.1 This specification is formulated to unify the technical requirements for low-pressure pipeline water supply irrigation projects in well irrigation areas and give full play to the benefits of the projects.
1.0.2This specification applies to the planning, design, construction, installation, acceptance, operation and maintenance of low-pressure pipeline water supply irrigation projects in the irrigation area.
1.0.3In the construction of low-pressure pipeline water supply irrigation projects, wells, water pumps, pipeline systems and field projects must be considered in a unified manner, and efforts must be made to be technologically advanced, economically reasonable and with significant benefits. 1.0.4Machine wells in low-pressure pipeline water supply irrigation projects: new wells must pass the well completion acceptance inspection; existing wells must be in good condition as specified in SD188 "Technical Specifications for Agricultural Wells". 1.0.5In addition to implementing this specification, the construction of low-pressure pipeline water supply irrigation projects shall also comply with the provisions of current relevant standards and specifications.
2Project Planning
2.1Planning Principles
2.1.1The natural geography, hydrometeorology, hydrogeology, surface soil, engineering status, agricultural production, social economy and topography of the planning area should be accurately occupied. 2.1.2 The planning should be carried out on the basis of local agricultural zoning and groundwater resource evaluation; it should be adapted to the overall planning of farmland water conservancy infrastructure construction, and should be adapted to local conditions, coordinated, comprehensively planned, and implemented in stages. 2.1.3 The technical and economic comparison of multiple schemes should be carried out in the planning to achieve the goals of low investment, high efficiency, water saving, energy saving, land saving and easy management.
2.1.4 When conducting technical and economic comparison of multiple schemes, the planning scheme should be selected based on the minimum annual cost. 2.1.5 The water quality of the water source should comply with the provisions of GB5084 "Water Quality Standard for Farmland Irrigation Water". 2.2 Main technical parameters
2.2.1 The irrigation design guarantee rate should be determined based on local natural and economic conditions and should not be less than 75%. 2.2.2 The water utilization coefficient of the pipe system should not be less than 0.95. 2.2.3 For irrigation areas with low-pressure pipeline water supply, the field engineering should be complete, the irrigation method should be reasonable, and the water quota should be appropriate. The field water utilization coefficient should not be less than 0.85. 2.2.4 The condensate utilization coefficient should not be less than 0.80. 2.2.5 The irrigation quota should be determined based on local irrigation test data. For areas without data, it can be determined by referring to the test data of neighboring areas. It can also be calculated according to the following formula: m—irrigation quota, m*/hm\
shallow drainage volume·water-saving irrigation volume
m=10007h3,-3）||t t||Y.- planned wet layer soil dry bulk density, kN/m\; h- planned wet layer soil depth, m; β-- suitable water content (weight percentage) upper limit, can be taken as 0.85 ~ 0.95 of field water holding capacity; β2- suitable water content (weight percentage) lower limit, can be taken as 0.60 ~ 0.65 of field water holding capacity. 2.3 Water supply and demand balance analysis
2.3.1 The available water volume should be determined based on the different typical annual groundwater recoverable volume provided by the groundwater resource evaluation results of the planning area, combined with the supporting equipment capacity: the well area should also review the groundwater resource evaluation results based on many years of mining and replenishment data, and analyze and determine the available water volume.
2.3.2 The water demand should include the water consumption for irrigation, animal husbandry, fishery, industry and life, and the development plan should be considered. 2.3.3 The irrigation water consumption in the corresponding typical year with different guarantee rates should be calculated and determined based on crop composition, multiple cropping index, crop water demand, and available precipitation.
2.3.4 The typical year method can be used to calculate the balance of water supply and demand. 2.3.5 When the water demand is greater than the water supply, it is advisable to adjust the planting ratio, reduce the irrigation area or increase the water source. 2.4 Pipeline system layout and ditch irrigation elements 2.4.1 Generally, a single parallel pipeline system is suitable; the use of a multi-parallel confluence system should be subject to technical and economic demonstration. 2.4.2 The tree-shaped pipe network or ring-shaped pipe network should be determined by comparison based on factors such as the location of the well, the shape of the plot, the planting direction and the supporting field engineering.
2.4.3 The number of pipeline levels should be determined based on factors such as the system irrigation area (or flow) and economic conditions; in early crop areas, when the system flow is less than 30m\/h, a first-level fixed pipeline can be used; when the system flow is between 30 and 60m/h, a two-level fixed pipeline of horizontal pipe (water transmission) and branch pipe (water distribution) can be used; when the system flow is greater than 60m\/h, two-level or multi-level fixed pipelines can be used.
For irrigation areas with highly permeable sandy soil, a ground mobile pipe should be added at the last stage. 2.4.4 The total length of the pipeline should be short, the pipeline should be straight, and the bending points and ups and downs should be reduced. 2.4.5 The length of the main and branch fixed pipelines in the irrigation area should be 90150m/hm2. 2.4.6 The direction of the branch pipe should be parallel to the crop planting row; the spacing between branches should be 50-150m, and the smaller value should be used for one-way irrigation and the larger value for two-way irrigation.
2.4.7 Water plugs (or water outlets) should be evenly arranged according to the irrigation area, and the spacing should be 50-100m. The irrigation area of a single outlet should be 0.25-0.6hm2, and the smaller value should be used for one-way irrigation and the larger value should be used for two-way irrigation. 2.4.8 The specifications and appropriate flow rates of dormant fields and irrigation ditches under low-pressure pipeline irrigation conditions should be determined based on local test data. For areas where no data is available, reference can be made to Tables 2.4.8-1 and 2.4.8-2 for selection. Wang
Ground slope
Ground slope
Planning results
SL/T153—95
Table 2.4.8-1 Field irrigation requirements
Single width flow
[L/(s · m)]
Table 2.4.8-2
0.002~0.005
Single width flow
[L/(s · m)]
Ditch irrigation requirements
0.002~0.005
80~100
0. 5~0. 6
A project planning report should be submitted. The report content should be divided into the following parts: (1) Preface;
(2) Basic information and data;
(3) Main technical parameters;
(4) Water balance calculation:
(5) Planning scheme and comparison;
(6) Field engineering;
(7) Pumped well installation:
(8) Implementation arrangement;
(9) Investment estimation;
(10) Economic benefit analysis:
(11) Attached drawings.
2.5.2 The attached drawings should include the following main drawings: (1) 1/5000 or 1/10000 current status map of water conservancy facilities; (2) 1/5000 or 1/10000 pipeline irrigation project planning map; (3) 1/1000 or 1/2000 typical pipeline system layout map. 0.005~0. 01
80~100
Single width flow
[L/(s + m)]
0.005~0.01
80~100
90~120
0. 6~0. 9
0. 4~0.6
3.1 Design flow
Irrigation and drainage volume, water-saving irrigation
3 Engineering design
3.1.1 The design flow of the irrigation system should be calculated according to the following formula Q. = amA
Q. Design flow of the irrigation system, m/h;
α--Controlled crop planting ratio;
A---Design irrigation area of the irrigation system, m\;\--Irrigation water utilization coefficient;
T-One irrigation duration, d;
t-Daily working hours, h.
When Q. is greater than the pump flow, Q. should be taken equal to the pump flow, and the irrigation area or planting ratio should be reduced accordingly. 3.1.2 The design flow of each level of the tree network should be calculated according to the following formula Q=Q.
Where Q is the design flow rate of the pipeline, m\/h; n is the number of water taps (or outlets) opened simultaneously within the control range of the pipeline; N is the number of water taps (or outlets) opened simultaneously in the entire system. (3.1.2)
3.1.3 The design flow rate of each level of the ring network pipeline should be determined according to the specific situation; the design flow rate of a single well and single ring network pipeline can be calculated according to the following formula
Q=Q:/2
3.1.4 The actual flow base of the pipeline system, each level of pipeline and water supply column (or outlet) should be determined by calculating the working point of the water pump.
3.2 Design head
3.2.1 The maximum and minimum working heads of the pipeline system should be calculated according to formula (3.2.1-1) and formula (3.2.1-2) respectively Hmx=Z. —Z. +AZ+Zhfz+hz
HminZ,-Zo+AZ+hn+Ehil
The maximum working head of the pipeline system, m:
Where Hmax—
HminThe minimum working head of the pipeline system, m
Z. The inlet elevation of the pipeline system, m;
(3.2.1-1)
(3.2.1-2)
Z,--the ground elevation of reference point 1: In the plain well area, reference point 1 is generally the outlet closest to the water source, m; Z2-the ground elevation of reference point 2; In the plain well area, reference point 2 is generally the outlet farthest from the water source, mAZ1, AZ2-are the center lines of the outlets at reference point 1 and reference point 2 respectively The height difference with the ground, m, the elevation of the SL/T153-95
line at the center of the outlet should be the highest ground elevation of the controlled field plus 0.15m; 121
EhnEhn
--the head loss and local head loss along the pipeline from the inlet of the pipeline system to the reference point 1, m; h, Zh---the head loss and local head loss along the pipeline from the inlet of the pipeline system to the reference point 2, m. 3.2.2 The design working head of the pipeline system should be taken as the average of the maximum and minimum working heads. Heax +Hmin
Where H.
The design working head of the pipeline system, m.
3.2.3 The design head of the irrigation system should be calculated according to the following formula Hp=H. +Z. -Za+Ehfo+Eho
Design head of irrigation system, m;
Za—dynamic water level of pump well, m;
respectively the head loss and local head loss along the pipeline from the inlet of water pump suction pipe to the inlet of pipeline system, m.
3.2.4The head (flow) range of water pump operation shall be determined by calculating the working point of water pump. 3.3 Head loss
3.3.【Head loss along the pipeline shall be calculated according to the following formulah
whereinhy
head loss along the pipeline, m;
fpipe friction coefficient;
pipe length, m;
D—inner diameter of pipeline, mm;
m-flow index;
-pipe diameter index.
The values of f, m, and 6 of various pipes can be taken according to Table 3.3.1. Table 3.3.1
Values of t, m, b
Pipe material category
Hard plastic pipe
Asbestos cement pipe
Old steel pipe, old cast iron pipe
Local material pipe
0.948×105
1.455×105
6.25×105
7.76n2×109
Note: 1. The value of t for buried thin-walled plastic pipe should be 1.05 times the value of hard plastic pipe in the table; 2. # is the roughness, cement sand pipe n=0.0143. 3.3.2 The local head loss of the pipeline should be calculated according to the following formula hj =g
where h, - local head loss, m;
local loss coefficient;
u—in-pipe velocity, m/s;
irrigation and drainage port·water-saving irrigation
g——gravitational acceleration, which is 9.81m/s. 3.3.3 The local head loss of the water faucet (or outlet) shall be determined according to the test or the data provided by the manufacturer; if there is no data, it can be selected as 0.3~0.5m.
3.4 Pipe diameter and pipeline working pressure
The diameter of each pipe section of the pipeline system shall be determined through technical and economic calculations; when initially estimating the pipe diameter, the in-pipe velocity can be selected according to Table 3.4.13.4.1
.
Table 3.4.1 Pipeline flow rate table
Flow rate (m/s)
Concrete pipe
Asbestos cement pipe
Cement sand pipe
Hard plastic pipe
Mobile hose
3.4.2 The design working pressure of each pipe section of the pipeline system should be 1.4 times the maximum working pressure (excluding impact pressure) under normal operation; the maximum working pressure should be determined based on various situations that may occur during operation. 3.4.3 Under normal operation (excluding impact pressure), the working pressure of the pipeline shall not be negative. 3.5 Water hammer pressure
3.5.1 When a one-way valve is installed in the pipeline system, the water hammer pressure when the pump is suddenly stopped should be verified. 3.5.2 Water hammer protection measures should be taken in the following situations: (1) In the case of water hammer, the pressure in the pipeline exceeds the nominal pressure of the pipe material; (2) In the case of water hammer, negative pressure may occur in the pipe. 3.6 Anchors
3.6.1 Anchors should be installed on pipelines when the following conditions are met: (1) The pressure head in the pipe is greater than or equal to 6m, and the pipe axis angle is greater than or equal to 15°; (2) The pressure head in the pipe is greater than or equal to 3m, and the pipe axis angle is greater than or equal to 30°; (3) The pipe axis angle is greater than or equal to 45°. Anchors should be installed on a solid foundation and their dimensions should be determined according to the force requirements. 3.6.21
3.7 Anti-scouring facilities at outlets
An anti-scouring pool should be installed at the outlet; anti-scouring measures should be taken for the outlet of ground mobile pipelines. 3.7.1
3.7.2 Anti-scouring pools should be made of local materials, and precast concrete components should be used first. 3.7.3 The bottom of the anti-scouring pool should be at least 15cm below the ground; the anti-scouring pool should cover an area of 0.1~0.25m2. 3.8 Other facilities
3.8.1 Intake and exhaust facilities should be installed at the high and downward bends of the undulating section of the pipeline axis; drain valves and seepage wells should be installed at the low points of the undulating section of the pipeline axis SL/T15395
and the lowest point of the pipeline system. 123
3.8.2 Negative pressure elimination facilities should be installed on the downstream side of the control valve of the slope pipeline, the upstream side of the control valve of the reverse slope pipeline, and the pipe section where negative pressure may occur.
3.8.3 For pipelines buried below the frozen layer and with a depth of not less than 70cm, temperature stress can be ignored; expansion joints or flexible joints can be installed when necessary.
3.9 Design results
3.9.1 The engineering design specification should be submitted.
3.9.2 The drawings in the specification should include the following main drawings: (1) 1/1000 or 1/2000 pipeline system layout; (2) Typical pipeline longitudinal section;
(3) Necessary connection and installation drawings;
(4) Design drawings of ancillary buildings;
(5) Pipeline cross-section:
(6) Typical field engineering layout drawings.
4 Water pump selection and matching
4.1 Selection and matching of new water distribution pumps
4.1.1 For new water distribution pumps for low-pressure pipeline water supply irrigation projects, it is advisable to use energy-saving products announced by the state, and it is strictly prohibited to use obsolete products announced by the state.
4.1.2 The flow rate of the selected water pump should meet the requirements of the design flow rate of the irrigation system and should not be greater than the water output of the well determined by the pumping test; the head should be reasonably selected according to the design head of the irrigation system; under the design flow rate of the irrigation system, the water pump should work in the high-efficiency zone.
4.1.3 The working point of the water pump should be checked separately under the maximum working head and minimum working head of the pipeline system to see whether it is in the high-efficiency zone. If the deviation is too large, the water pump should be reselected or the design of the pipeline system should be adjusted. 4.1.4 The matching pump pipe of the well submersible pump can be enlarged by one level under economically reasonable conditions, but it should not affect the installation and maintenance of the water pump.
4.1.5 In addition to complying with this specification, the selection and matching of water pumps shall also comply with the requirements of the "Technical Specifications for Agricultural Machinery and Equipment" (SD188).
4.2 Utilization and transformation of existing machine-well devices
4.2.1 When using existing machine-well devices to construct low-pressure pipeline water supply irrigation projects, relevant technical data should be collected, and performance parameters such as water pump head, flow, speed and power machine energy consumption should be tested. According to the technical indicators, current technical conditions, design requirements, etc. of the water pump and supporting devices, the feasibility of its utilization and transformation should be determined through technical demonstration and economic analysis. 4.2.2 A specific technical transformation plan for existing machine-well devices should be formulated, and transformation, maintenance and acceptance should be carried out accordingly. 124
Huang Girding Drainage Volume·Water-saving Irrigation Creek
4.2.3 The water pumps that have been repaired or technically transformed should comply with the provisions of Articles 4.1.2 and 4.1.3. 4.3 Efficiency of pumped well installation
4.3.1 The efficiency of pumped well installation is calculated as follows:
Q(H -Za) × 100%
Wherein, the efficiency of pumped well installation;
—Specific gravity of water, N/m;
Q. —- Actual flow rate of irrigation system, m\/s#H:- Actual working head of pipeline system, m
N,- Input power of power machine, kW.
4.3.2 The efficiency of newly equipped pumped well installation shall meet the indicators specified in the Technical Specifications for Agricultural Pumped Wells (SD188); the efficiency of existing pumped well installation shall not be less than 35% for electric motors and not less than 30% for diesel engines. 5 Pipes and fittings
5.1 General provisions
5.1.1 Pipes and fittings used in low-pressure pipeline water supply irrigation projects must comply with the following provisions: (1) Pipes and fittings not manufactured on site should be standardized products, or non-standard products that have undergone technical appraisal and are produced strictly in accordance with technical requirements;
(2) Pipes and fittings manufactured on site should undergo technical appraisal, and corresponding measures should be taken to ensure that their quality is not lower than the indicators at the time of appraisal.
5.1.2 The nominal pressure of the pipe should be greater than or equal to the designed working pressure of the pipeline. 5.1.3 The nominal pressure of the fitting should be greater than or equal to the nominal pressure of the pipe; its specifications, dimensions and deviations should meet the connection sealing requirements.
5.1.4 Cement prefabricated pipes and cast-in-place concrete pipes should not be buried in soils with a sulfate concentration exceeding 1%. When burying pipes in soils with a sulfate concentration greater than 0.1% and less than 1%, cement with a tricalcium lead content of less than 5.5% should be used. 5.2 Plastic pipes and connectors
5.2.1 Thin-walled or double-walled plastic pipes should be used for low-pressure water supply plastic pipes; their performance indicators and tests should comply with the provisions of relevant standards.
5.2.2 The total radial deformation rate (i.e. the ratio of radial deformation to outer diameter) of buried plastic pipes caused by static loads and dynamic loads shall not be greater than 5%; when the burial depth is greater than 70cm, the dynamic load can be ignored. The calculation method of radial deformation of pipelines is shown in Appendix B. 5.2.3 The material of plastic connectors should be the same as that of the pipes. 5.2.4 Welded rigid polyvinyl chloride or high-density polyethylene connectors should meet the following mechanical property requirements: (1) No rupture after free fall from a height of 1m;
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