Almost every master faced the need to tie into the highway. The technology of work in this case will depend on what pipeline material is used. Utility systems today are assembled from cast iron, galvanized and polymer pipes, but for completeness of information, all technologies should be considered at once. So, let's start the description of each method separately.
Piece using polymer reinforcement
The tie-in into the polymer pipeline will be carried out according to a certain technology. At the first stage, it is necessary to reach the highway by digging a square-shaped pit. Its dimensions should be 1.5x1.5 m. Earthworks at the initial stage are carried out using special equipment. But once you've reached the metal band piping system that's at the top of the line, you'll need to use a shovel to get past the remaining 40cm.
After you see the pipe, you can proceed to dig a trench to the building. Having finished with this, you should begin to equip the outlet. For this, specialclamps, which are also called saddles. These elements are collapsible and are used for tapping into the water supply system. They can be compared with tees, the straight-through pipes of which have two parts. Single clamps and clips can be installed on plastic products. However, saddles will be the most suitable option, because the electrofusion collar is collapsible.
When tapping into a pipeline using this technology, the clamp must be installed over the tie-in point and connected using an electric welder. As soon as these works are completed, the saddle should be inserted into the pipe body, which will ensure a reliable connection and high tightness.
Work methodology
The next step is to drill the pipe using a hole saw or a regular drill. The diameter of the tool must be smaller than this parameter, which is characteristic of the upper nozzle of the saddle. The drill must be inserted into the pipe through the shut-off valve that shuts off the pipes. Drilling is performed using a special nozzle, which guarantees the tightness of the joint.
Some models of saddles involve embedding the cutter crown into the bends. It should be rotated with a forked key. At the final stage, it will be necessary to bring the pipe into the trench, connecting it with a valve. This uses a compression sleeve.
Specialist recommendations
When tapping into a pipeline using the technology described above, a manhole can be placed at the installation site. For this bottomthe pit is deepened, sand and gravel are poured on it, and then rings are installed, the first of which will have a hole for pipes. The pillow, if desired, is strengthened by pouring concrete, the thickness of which should be 10 cm. To do this, you need to use the M-150 or M-200 brand. It is important to bring the head of the well with a hatch to the zero level of the soil. This design facilitates the repair of the plumbing system. The consumer will be able to shut off the system using the central valve.
Piece into cast iron pipe
When you have a cast-iron sewer pipe in front of you, the tie-in into it is carried out using a different technology. This is due to the fact that metal products are harder than polymer ones, but the plasticity of the material is not so high. This indicates that the cast iron may simply burst.
Therefore, when tie-in, the pipe must be dug up and cleaned of rust in the place where the work will be carried out. The top layer of compacted cast iron must be cut off with an angle grinder at the point where you will be embedding. A saddle is installed on the pipe, and a rubber seal is located between the clamp and the fittings. The joint must be sealed.
Work technology
When you have a cast-iron sewer pipe in front of you, the next step is to fix the shut-off valve to the saddle flange outlets. Through the first and have to start a crown. The cast-iron pipe is drilled, while it will be necessary to cool the work site and change failed pipes from time to time.crowns. In this case, you need to use a special cutting tool that has carbide inserts. It will not be possible to cut the material using other equipment. At the final stage, the crown is removed, the water flow is blocked, and the installation of the external branch is carried out according to the standard rules.
Installation of a manhole at the tie-in location
When tapping into a pipeline, a manhole can be installed. This action is desirable but can be omitted. Steel products in terms of ring stiffness are in no way inferior to cast iron fittings, however, they are more ductile compared to cast iron. This explains the possibility of using the original technology when tapping into a steel pipe. The technique is similar to that where polymer products are used.
Arrangement of a tie-in into a steel pipeline is carried out according to a certain technology. The pipe must be cleaned, freed from rust and prepared for work. A flanged threaded pipe is welded onto the product, which is made from main fittings. For the branch pipe, it is permissible to use any type of rolled pipe, the main thing is that structural steel is the basis.
Important to remember
When tapping into a water pipe, after forming the seam, it should be checked for strength. From the inside, the surface is smeared with kerosene, and outside the place must be marked with chalk. Oil stains will appear on the outer surface, which will indicate joint defects.
Features of theworks
Once you have completed all the work that was described above, a threaded or flanged valve can be strengthened to the nozzle. The pipe is drilled through the valve, and the upper layers can be overcome with an electric drill. You can drill the last millimeters by hand. Behind the valve, a branch of the external water supply system is installed, which is brought into the house through an open trench.
When tapping into a water pipe, the slope of the outer branch of the saddle pipe should be 2 °, and it must be directed towards the house. As soon as the outer branch can be collected, it should be checked for leaks. The trench must be buried in the place where the tie-in to the house was made, but this can only be done after the tightness test is completed.
Tie in gas pipeline
A gas pipeline is a structure through which gas is transported. Depending on the purpose, it can be supplied under different pressure. For example, if we are talking about main pipelines, then the pressure in them is quite high, while in distribution systems it can change.
A tie-in to a gas pipeline without stopping work can be carried out during the repair and connection of individual consumers. The system will work without interruption and the pressure will not be reduced. This technology is also called cold tapping and is sometimes replaced by a more traditional method that involves welding the pipe and is considered labor intensive.
Inset tothe gas pipeline when using plastic pipes is carried out using fittings or fittings. For this, metal elements are used, and the method provides for a socket connection, which is glued with special compounds after installation is completed. The steel insert is treated with compounds that can protect the surface from rust, because water ingress can cause corrosion processes.
Insert is carried out by creating alloy inserts perpendicular to the pipe. The insert has a length ranging from 70 to 100 mm and is built up by the method of socket contact connection. This method implies that plastic pipes are placed on a heated steel insert. The method is used to create branches from gas pipelines with low pressure. If the pressure is medium, then before building up, it is necessary to apply powdered polyethylene to the place of the future connection, which will ensure tight adhesion of the two materials.
Features of the tie-in
Installation into the pipeline of cold water supply can be carried out using several technologies. For this, different types of welds can be used, namely:
- tee;
- butt;
- angular;
- lapped.
For tie-in without pressure release, not only saddles are used, but also devices that are known as PGVM. In addition, latches and clamps can be used. If the option with a valve is selected, then a coupling and a branch pipe are welded to the pipe, to which the valve with a chamber is attached. The hole must have a cup cutter, after which the cut fragment is removed through the chamber, and the valve is closed. When tapping into an existing pipeline using this technology is carried out, a branch is connected to the flange after the above work.
As for the PGVM, it is a device that is designed for tie-in without pressure relief. The element is used for gas pipeline systems that have a diameter ranging from 186 to 529 mm. Using this device, you can perform a tie-in, pre-creating holes, the diameter of which will vary from 80 to 140 mm.
Conclusion
If you use a mortise pipe clamp, then a branch can be provided from the main water supply line of a residential building. It is sometimes required to connect an additional consumer or irrigation system device. If the system uses water from a well, then tapping can be done anywhere. If we are talking about central water supply, such work is carried out behind a water consumption meter. In this case, the tie-in into the pipeline under pressure will differ from the technology described above.
This is due to the fact that the pressure in the internal network is turned off at any time. To do this, it will only be necessary to close the central valve. Therefore, for the work you need to prepare a tee. Manipulations will involve the need to drain the water, this is done by opening the bottom tap.
