This was my invitation, thanks for coming!
I invite you to read the third installment that I will be publishing soon. And where I will address the issues of Aqueduct, Gasification, Electricity and Paving in streets.
I was telling that in the trunk, space that forms the street, called road body, between curbstone and curbstone is an interesting swarm of pipes and pieces, which ultimately lead the services that provide comfort, safety and welfare.
Thus, for example, we have:
1. Direct gas
This is one of the activities in which I found myself more uncomfortable despite how interesting it is to do it, but I had never had the opportunity to work with direct gas and neither had our staff, so it was necessary to take a brief introductory and intensive course for 1 week with the technical staff of PDVSA - GAS (Eng. Omar Lujano and technical support staff), then Eng. Lujano would be my inspector on site.
Our installer and on the right, Eng. Omar Lujano, PDVS-GAS inspector.
My country, Venezuela, is a founding member of OPEC, Organization of Petroleum Exporting Countries and is among the first in gas reserves. Recently there have been problems with the distribution and supply to the people with the traditional system of gas cylinders, in my house is the type of gas we use.
Oiza waiting for gas!
But the state has been working for the direct gas supply and this is the alternative with which we work in the neighborhoods mentioned above, Democracia A - B; Buen Samaritano; Próceres de la Florida and Bolivariano.
Plan of direct gas distribution in popular neighborhoods
In the construction of distribution network to the neighborhoods, the connection to the mother pipe is executed by PDVSA-GAS, we ( Inversiones Peñate C.A), we start from that point and it is done with the 110 mm pipe, and we call it main branch, this pipe is made of HDPE (High Density Polyethylene), yellow color of 5 mm thick and comes in rolls of 100 mt. And it extends longitudinally through the main road arteries of the urbanism, from which the netting of the distribution system in the neighborhood is conformed.
The other components are:
1. -Pipelines 90, 63 and 32 mm.
2. Supply valves, bypass, sectioning or shut-off valve for maintenance and shut-off valves for the customer or F4 - F5.
3. Transitions, transition from 30 bar to 0.05 bar pressure.
4. Connections: Elbows; Rings; Clamps, Tee, Valves was what we use.
5. Spy Cable TTU12
6. Sifted sand
7. Mortar Rcc150 kg/cm2
8. Safety tape.
9. Heavy galvanized iron pipe
10. Heavy galvanized iron quick closing valves.
In the road body that has all or most of the utilities the distribution is done as follows:
A. - In the axis of the roadway is placed the sewage pipe (A.N), it is the deepest and has the largest diameter.
B. To one side of this pipe and with a minimum separation of 30 cn in all directions is placed the GAS pipe, it must be at a minimum depth of 1 mt.
C. The aqueduct pipe is installed 25 cm from the curbstone and at a depth of 70 cm, it must also have a minimum separation of 30 cm from the gas pipe.
1. Backhoe machine with 30 cm tuff.
2. Electrofusion equipment
3. Recorder equipment
4. Minor tools
We proceed to stake out the section to be worked on, followed by the excavation of the main pipe. The location of the sewage pipes, which is the initial network installed, must be observed,
Once the main branch with the 110mm pipe is in place, the installation of the bypass valves, sectioning valves or maintenance valves is done, at the end of the branch a closing plug is placed.
At the end of the branch, a closing plug is placed at the end of the branch. In the bypass valves, the pipe diameter of 90 or 63 mm will be mounted, in these branches will be installed the transitions that will make the transition from the operating pressure to the pressure of use in our case 30 psi and 0.05 psi.
Pressure change point transition
Once the excavation is done, a 20 cm thick sifted sand base will be placed to protect the pipeline, it will also be covered with a 30 cm thick layer and on this layer a yellow tape with the danger sign will be placed, with the objective that if the area is ever intervened, when the tape and the sand lens are seen, the proximity of the pipeline will be known.
A base is built on the sidewalk to support the house containing the stopcock and the house installation.
At pavement level, the points of the valves and also the route of the entire pipeline are marked with plates embedded in the concrete.
Spy Cable TTU-12 It is a very important element as far as security is concerned, this CABLE is twisted to the pipe and with an electromagnetic detector.
Pressurized Test: The pressurized test is performed in stages and preferably before plugging the pipe or always leaving the space where the high points are uncovered. This test consists of filling the pipe up to 110 psi and leaving everything closed for 24 hours, (there is a machine with a disk) that together with a manometer will indicate if there is a leak in the sector.
House and home supply: Once the gas is in the house, the connection is made with a 3/8" pipe that is embedded in the floor and wall and is placed 1m away from the kitchen, with a stopcock that allows the gas to be shut off immediately.
It is the third of the services placed in the roadway, the biggest job is to connect to the main branch due to the diameter of the pipe. In this case we did it using a metallic piece conformed by two shells and capable of wrapping a 20 inches pipe, this piece is called "cachicamo". One of the shells has a 4-inch nipple welded to it with a flange to which a 4-inch flanged stopcock is connected. Once the tap is made, we work with adapters to work with 110 mm HDPE (high density polyurethane) pipe and we build, similar to the case of gas, the aqueduct meshing. And for this we need:
1. Piece to embrace 20 inch pipe (cachicamo) 2.
100 mm HDPE pipe, main branch.
HDPE pipe 63 mm secondary branch
3" internal stopcock
Once the connection to the pipe has been made, the excavation is made, the depth of which does not exceed 70 cm and at 25 30 cm separated from the curbstone, in the roadway,
The pipe of the main branch, in this case of 110mm, is extended on a 15cm thick sifted sand base and the secondary branches are connected by means of clamps.
This operation is repeated with the secondary branches, but the clamps will be to feed the house outlets.
Working with this type of piping has greatly simplified the construction of aqueducts for these types of urban developments.
Stopcocks inside the urban development
Household stopcock for access to the aqueduct.
It became very extensive the writing, without wanting to abuse my readers I invite you to read the next writing and end of this series, where I will present Electricity and Roads.
Original photographic support and writing by oizaguirres for raed.cash.
Translated with www.DeepL.com/Translator (free version)