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Posts Tagged ‘pipe’

Land drains in agriculture.

Traditionally, land drains were formed in clay soils and peats by excavating a trench and forming a “tunnel” using flat stones, this was very labour intensive but could be often be done using free materials to hand. Typically they were two to three feet (600mm-900mm) below the surface. Agricultural land drains have to be installed sufficiently deep to avoid plough damage.

Later short earthenware pipes were used laid edge to edge. These are still used. These can be laid in an excavated trench, more usually these days, a horizontal hole is formed in the ground using a mole plough and the pipes are forced in by means of a hand or mechanical press.

By this means, heavy wet soils, bogs and swamps could be rendered amendable to agriculture. Virtually all crops need a well drained soil to grow well.

Modern land drains.

Many modern land drains are created utilising rigid or flexible plastic pipes pierced with holes, laid in pea gravel . (The pea gravel is pea sized pebbles without sharp points to damage to pipe.) Geotextile material can surround the gravel to keep out silt. This can be installed in an excavated trench or…

Specialised mole ploughs are available that can form the hole, insert the perforated pipe (and gravel if required), all in one simultaneous and continuous process. An extremely powerful (usually tracked) tractor is necessary. The flexible pipe is carried as a roll on the back of the machine. There is a sometimes a hopper for gravel which is kept topped up by an adjacent machine. The pipe and gravel go down apertures in the plough blade as the tractor proceeds along the desired route.

Land drains in building construction.

The purpose of land drains in building construction is somewhat different. If voids are created in the ground for any reason they tend to fill with water. Also the static loads on any subterranean structure and retaining walls can be massively increased by the presence of water in the surrounding ground. Land drains are introduced to relieve this pressure. Traditionally, the drains were created by backfilling behind retaining walls etc. with rubble and allowing the water to drain through the rubble to some suitable point.

Land drains as part of highway construction.

Instead of having open ditches at the side of highways, land drains can be installed. The excavated trenches are completely filled with gravel(ie, no soil cover). This is far safer if a vehicle should run off the highway.

Problems

Holes or gaps have to be left in the pipes to allow water to transfer from the subsoil to the pipe and these tend to block with soil or allow silt into the pipe so blocking it or reducing the flow of water. This can be partially overcome by surroung the pipes with gravel. However with time even the gravel becomes choked with soil/silt, so in the latest practice, the gravel is surrounded with a “geotextile” material which filters out soil particles. Ideally, land drains are laid with access points so that high pressure water jetting is possible to clear silt.

However, whatever the technology, all land drains have a finite life and eventually become ineffective due to the ingress of silt and/or the blocking of the surrounding filter media.

Categories: Agricultural soil science | Building engineering | Hydraulic engineering | Hydrology | Land management | Archaeological featuresHidden categories: Articles that need to be wikified from November 2008 | All articles that need to be wikified | Articles lacking sources from November 2008 | All articles lacking sources

Sometimes a pipe is in such bad condition that modern sewer pipe lining is not possible. Examples would be when extensive sections of the pipe are partially collapsed which is common for Orangeburg pipe, or large sections of pipe are missing which is common for cast iron pipe, or a customer is unfamiliar with pipe re-lining, which is the more modern method used in trenchless pipe rehabilitation. In such cases pipe bursting technology is used.

The pipe bursting technology involves pulling a cone-shaped “head”, with a new high density polyethylene (HDPE) pipe attached, through an existing pipeline. As the head moves through, it breaks the old pipe and pushes the pieces back into the surrounding soil. The head also expands the bore diameter slightly larger than the outside diameter of the new pipe it is pulling in. This reduces friction, but it also makes it possible to replace an existing pipeline with one of a larger diameter. Of course very powerful winches and strong cables have to be used for this type of sewer pipe rehabilitation.

A bursting head with no other attachment is called a static head, and it depends entirely upon the power of a winch to pull it through an existing pipeline. In some cases, a bursting head is equipped with a cutting blade or an internal pneumatic hammer. The cutting blade concentrates all the pulling force into one area, making the initial opening of the pipe easier. In hard, dry soils, or when heavy pipe fittings are encountered, the driving force of a hammer aids penetration.

As the HDPE pipe is pulled into the old sewer pipe that requires replacement, new sections of HDPE pipe are fused together using a plastic welding technology. This makes a seamless pipe that will prevent root intrusion, water infiltration and exfiltration.

There are some limitations to using the pipe bursting process:

The first is the line has to be in good enough condition for the cable to be pulled through the line.

Pipe Bursting will not fix a sag, or, belly. The bursting head and new pipe follows the path of the old pipe.

Rocks, ledge and some other conditions may jam the bursting head preventing it from passing and still require excavation to complete the job.

Some bend configurations may not allow pipe bursting as the bursting head may exit the pipe and get stuck requiring excavation.

Each installation starts with excavation of a small pit (about two feet by three feet) at the property line and another where the service line enters the house. Vacuum excavation is used to open the pits because many utilities are clustered near the property lines. The soil is cut with a water jet, then vacuumed out by a Vactor truck with a 6-inch tube. Usually, the pits can be excavated in less than an hour.

City code in Sarasota requires that a cleanout be installed every 75 feet in new service laterals. For laterals over 75 feet long, pits are sometimes dug for the extra cleanouts, and the new pipe is pulled from one pit to the next. At other times, the entire length of the new line is pulled first and the cleanouts are installed later. We used small, modular equipment manufactured by Tric Tools, Inc. (www.trictrenchless.com) to install the new lateral lines. Normally, the pulling equipment is set up in the pit at the property line because it is deeper, and therefore offers more head wall surface to pull against. The Tric hydraulic puller can produce a pulling force of 60,000 pounds. The white, 4-inch SDR 17 HDPE (high density polyethylene) pipe is supplied on 800-foot reels. The color enhances video inspections, and the length greatly reduces the need for onsite pipe fusion.

When the pits are ready, a cable is strung through the existing service line from the property line to the house. There, the cable is attached to a 4-inch bursting head, which has a special blade to help crack or cut the old pipe. In turn, the bursting head is fused to the new pipe. In the pulling pit, the cable runs through a resistance plate and metal frame before it attaches to the hydraulic puller. A diesel-powered Vermeer high pressure pump supplies hydraulic power to the puller. Once the pull begins, the new HDPE pipe is pulled into place at 5 to 10 feet per minute, depending upon the power of the hydraulic pump.

Site prep is the best term that is used to describe the operations necessary to make raw land ready to accept improvements such as buildings, parking lots, roads, and other amenities. Once the project has been completed, the site prep is invisible.

The term site prep is a broad term that can include several different tasks, such as clearing and grubbing, soil erosion, sediment control, storm drains, water and sewer pipes, topsoil stripping, rock removal, underground utility, and several other tasks.

Soil erosion and management

To protect the quality of the water, soil erosion and sediment control measures are vital. With most locations, storm water permitting is required. All erosion and sediment control measures and devices must be in place and inspected before the first tree drops or first shovel full of dirt is removed.

The designs for storm water management systems are becoming more and more complex. The detension basins have complex and spiraling side slopes and bottoms that have almost flat grades.

Clearing

The limits of clearing can be marked with a GPS dozer. By following the outline of the display in the cab, the bulldozer can cut a path through the wooded area so other equipment will have a clear line to go by.

The traditional method used to clear debris, such as burning, is rapidly fading away. The air pollution standards will prevent any type of burning of most areas across the United States.

Site prep made easy

Depending on the job site, what you have to do will vary greatly. With excavation, what is needed to complete a job is as different as night and day. No matter what type of work you are doing, it will almost always require the use of heavy machinery.

Clearing lots for houses, grading roads, laying pipe, fixing water leaks, and digging foundations are just some of the most common tasks found with the art of excavation. To do this type of work, it takes a special individual as work is outdoors year round, meaning that you freeze in the winter and burn up in the summer.

Laying pipe is a task that takes skill. You first must dig the trench for the pipe, making sure that the elevation is right, and that the pipe will meet the specifications listed in the blueprints. There are several different types of pipe that needs to be layed, including water, sewer, and storm drains.

When you first begin your job, you’ll need to have the proper permits from the area that you are going to be disturbing the ground in. Once you have the proper permits, you can begin your work. With some jobs, you’ll need to document on paper just how much land you disturb each day.  

Sometimes with excavation, the job site and plans will call for ponds or temporary ponds. This can be fun to do, although you have to be careful as well. Very common with sub divisions, ponds are something that take a lot of skill to dig right.

Manholes are something else that you will encounter as well. You can use machinery to set them in place, although they will need to go a certain way. The easiest way to put them in place is by using an excavator, as you can lower it down and have a couple of workers set it in place.

Anytime you are working on an excavation site, you should always be careful and make sure you do things by the book. There are always rules and regulations that you need to follow. Excavation is a very fun trade, although you’ll need to be well versed with following plans, running machinery, and having fun outdoors.

Hydraulics is a branch of engineering science which is concerned with the mechanical properties of liquids and the general power of fluids.

It is also focused mainly on the engineering uses of fluid properties. Hydraulics, therefore, derived its theoretical foundation fluid mechanics. Hydraulics spans a vast scope of topics, ranging from science to engineering disciplines.

Among the concepts it covers include dam designs, turbines, pumps, circuitry, pipe flow, hydropower, river channel behavior and erosion.

Machineries using the principles of hydraulics include bulldozers, backhoes, forklifts, cranes, and shovel loaders. Hydraulics is also the reason why we see cars being lifted in service centers so that technicians can work beneath them.

It is also because of this same technique that elevators operate. Airplane surfaces are operated and controlled by hydraulics, and even the brakes in our cars use hydraulics.

The idea behind hydraulic systems is simple. It states that force applied at a point gets transmitted to the next point with the use of an incompressible fluid, which is usually a type of oil. In the process, the force is being multiplied.

In a simple hydraulic system, two pistons are connected by a pipe which is filled by oil. These pistons are installed into two glass cylinders which are filled with oil. The glass cylinders are then connected to each other by a pipe filled with oil.

When force is applied to one piston, the force is transferred to the next piston through the oil in the pipe. Because oil cannot be compressed, the efficiency is very good because all of the force applied shows in the second piston.

The pipe which connects the cylinders can also come in any length, shape and size, so it can bend, twist, or turn through all the things separating the two pistons. This pipe can also be a fork, which simply means that one master cylinder can drive one or more slave cylinders.

In hydraulics, it is very important that the system eliminates air bubbles. The presence of air bubbles in the system affects its efficiency as the force being applied to a piston compresses the air in the bubble rather than transferring it to the second piston.

The brakes in a car are the simplest example of piston-driven hydraulic system. As the brake pedal is pressed down, it pushes the piston in the brake’s master cylinder. This action drives four slave pistons to push the brake pads towards the brake rotor so the car stops.

The force coming from your leg is not enough to stop the car, so car multiples the force. This is called hydraulic multiplication. In most cars today, there are two master cylinders driving two lave cylinders each.

This design allows the car to brake or stop even if there is problem in the first brake, or if there is an oil leak. In other hydraulic systems, valves connect cylinders and pistons to a pump which supplies high-pressure oil. The valve applies forward and backward force to the pistons.

You can see large hydraulic machines in construction sites. These machines, driven by hydraulic power include excavators, skidloaders (also known as the “bobcat”, because it was the name given by its first manufacturers), and dump trucks.

When you see these machines, remember that despite their enormous sizes, the common force driving them comes from hydraulics.

If your residence or commercial building needs sewer repairs, the plumbers in Los Angeles are ready to help. Using state-of-the-art technology and video inspections, they can pinpoint your sewer problems quickly and efficiently.

In Los Angeles and the surrounding area, people do not like the destruction that comes with traditional sewer line repairs. The video inspection also reveals whether you have cracks in your sewer lines, root intrusion, or a complete collapse of your sewer line. The video inspection is achieved by connecting a tiny camera to the end of an auger line.

Trenchless technology, available in most cases, allows the plumbers to make repairs from just two small access points, one on either end of the line. This means faster repairs and minimal disruption to your landscaping, yard, or driveway because the entire sewer line does not need to be uncovered.

For many years, getting to sewer lines to replace and repair meant large scale excavation. This was both a costly and a lengthy process, leaving you with a yard and driveway to repair once the sewer was repaired. Many times the cost to replace trees, sidewalks, driveways, and landscaping exceeded the cost of the sewer repair.

Advances in technology now allow for trenchless sewer line repair, and plumbers in Los Angeles have been leaders in the industry in this specialized area. There are two different options for trenchless sewer repair. One is pipe relining and the other is pipe bursting. Pipe bursting involves bursting the old pipe apart as a new pipe is pulled through.

The old, original pipe acts as a guide as the new pipe is pulled through. It is then ripped apart by the equipment pulling in this new pipe. You are left with a strong new pipe exactly in the same place as where the old pipe was.

Pipe relining has some similarities, but instead of splitting the old pipe apart to replace it, a fiberglass liner is places inside of the damaged pipes. The pipes are sealed, and your pipes will now last for many years to come. Relining may last as long as several decades, depending on how the work is completed and other details.

Trenchless sewer repair is the way to go to avoid costly damage to trees, sidewalks, driveways, and landscaping. If you are given the choice, and it is completely up to you, opt for a trenchless sewer line repair in order to maintain the plumbing and sewer system in your residential or commercial building.