Pre-Buried Drain and Pipes Steps for Corrugated Galvanized Steel Tank
Preparation
1.1 Material preparation
1.1.1 Drainage pipe material:
PVC (polyvinyl chloride) pipe or PPR (random copolymer polypropylene) pipe is usually selected.
PVC pipe is relatively cheap and easy to install; PPR pipe has better performance, strong corrosion
resistance and long service life. The pipe diameter is determined according to the size of the water tank
and the drainage flow requirements. Generally, small water tanks (volume less than 10 cubic meters) can
use pipes with a diameter of 50-75mm, medium-sized water tanks (10-50 cubic meters) use pipes with a diameter
of 75-110mm, and large water tanks (more than 50 cubic meters) may require pipes with a diameter of more than 110mm.
1.1.2 Pipe fittings:
including elbows, tees, and straight joints. Elbows are used to change the drainage direction, for example,
when the drainage pipe needs to bypass obstacles such as water tank brackets; tees can be used to connect branch pipes,
such as connecting drainage and overflow pipes at the same time; straight joints are used for straight connections of pipes.
The specifications of the pipe fittings should match the selected drainage pipe.
1.1.3 Valves:
Choose suitable drainage valves, such as gate valves, butterfly valves or ball valves.
Gate valves have good sealing performance and low fluid resistance, and are suitable for large-diameter pipes;
butterfly valves open and close quickly and take up little space; ball valves are easy to operate and have precise flow regulation.
The size of the valve is determined according to the pipe diameter, and attention should be paid to the quality and sealing performance of the valve.
1.1.4 Sealing materials:
such as PVC glue (for PVC pipe connections), rubber sealing rings (for enhancing the sealing of pipe interfaces and pipe fitting connections),
and raw tape (for sealing at valve interfaces).
1.2 Tool preparation
1.2.1 Cutting tools:
hand saws or special pipe cutters. Hand saws can be used to cut pipes of various diameters,
but the pipe mouths may not be smooth after cutting; special pipe cutters can make the cutting surface neater,
especially for harder pipes such as PPR pipes, the cutting effect is better.
1.2.2 Installation tools:
wrench (for tightening nuts on pipe fittings and valves), screwdriver (for fixing auxiliary accessories such as pipe clamps).
Plan the layout of drainage pipes and dig trenches
2.1. Determine the location of the drain outlet
2.1.1 Bottom drainage is preferred: The drain outlet is preferably set at the bottom of the water tank,
so that complete drainage can be achieved to avoid residual water in the water tank,
which may cause water quality deterioration or bacterial growth. For the bottom of the water tank with a slope,
the drain outlet should be located at the lowest point.
2.1.2 Consider the purpose of the water tank and subsequent equipment connection:
If the water tank is used for a water supply system, the location of the drain outlet should be convenient for
connection to subsequent water treatment equipment or water supply pipelines; if it is used for special purposes
such as fire protection, the layout of the drain outlet must comply with the requirements of relevant fire protection
regulations, and may need to be connected to a specific drainage system.
2.2. Dig trenches
2.2.1 Dig trenches according to the pipe diameter and burial depth requirements,
and ensure that the bottom of the trench is flat and has a certain slope (generally 0.5%-1%).
2.2.2 The trench width should be slightly larger than the outer diameter of the pipe to facilitate installation and backfilling.
2.2.3 If the soil is soft or there is a risk of collapse, support plates can be used to reinforce the trench.
Pipeline installation
3.1. Cut the pipe to the appropriate length
According to the design direction of the drainage pipe and the actual installation distance, use a cutting tool to cut the
pipe to the appropriate length. When cutting, ensure that the cutting surface of the pipe is flat and vertical.
For PPR pipes, it may be necessary to simply clean the pipe mouth after cutting to remove the debris generated during the cutting process.
3.2. Pipeline connection preparation
3.2.1 PVC pipe connection: For PVC pipes, evenly apply PVC glue to the end of the pipe inserted into the pipe fitting and inside the pipe fitting.
Apply glue in an appropriate amount to avoid excessive glue entering the pipe and affecting drainage.
3.2.2 PPR pipe connection: PPR pipes are generally connected by hot melt. Use hot-melt welding equipment to heat the connection
parts of the pipe and the pipe fitting to an appropriate temperature at the same time (the hot-melt temperature of
PPR pipes is generally around 260°C), and then quickly insert the pipe into the pipe fitting. During the insertion process,
the axis of the pipe and the pipe fitting should be kept consistent, and the insertion depth should meet the marking requirements of the pipe fitting.
After waiting for cooling and solidification, the pipe and the pipe fitting are firmly connected together.
3.2.3 Install rubber sealing rings: Install rubber sealing rings at the connection between the drainage pipe and the water tank wall and some
key pipe fitting connections (such as elbows, tees, etc.). Place the sealing ring in the sealing groove of the pipe fitting or in the gap between
the pipe and the water tank wall to ensure that the sealing ring is installed flat without distortion or damage.
Backfill soil
First fill and compact the area around the pipe with fine sand or gravel to avoid uneven force on the pipe.
Backfill the soil in layers, with each layer not exceeding 30 cm thick, and compact it layer by layer.
Be careful not to damage the surface of the pipe.
Testing and acceptance
Fill water into the pipe to check for leakage.
Ensure that the drainage system operates normally and the water flows smoothly without blockage.