Background to Concrete Pumps
A concrete pump is a tool for conveying liquid concrete.
Over a period of more than half a century, concrete pumps have slowly taken over from other methods of transferring liquid concrete. A number of different designs of concrete pump were developed in the first half of the 20th century but it was Friedrich Wilhelm Schwing's company Schwing GmbH which invented the twin cylinder hydraulic concrete pump in 1957. The principle of this design was adopted by almost all other manufacturers and is still the worldwide standard design.
The pump works by one piston drawing liquid concrete into a cylinder from a hopper while the other one simultaneously pushes its concrete out into the discharge pipes. A valve which determines which cylinder is open to the concrete hopper and which one is open to the discharge pipes switches over each time the pistons reach the end point (see rock valve below and animation left - click to enlarge) and the process continues with the first cylinder now discharging and the second drawing fresh concrete from the hopper.
The Concrete Pump was particularly important in revolutionising the construction of large high rise buildings. Previously cranes had been employed to lift large buckets (or skips) full of concrete up to where it was needed. A crane could lift one bucket at a time, normally holding around 2 cubic yards of concrete.
There are many advantages in pumping concrete over this bucket and crane system. As well as being able to pump concrete much faster than buckets could lift it, it also means a constant supply of concrete to the top and the placing hoses can be positioned wherever they need to be so the liquid concrete can pour straight out of the hose where it's needed rather than having to distribute a two cubic yard mound of concrete over the desired area.
Advantages of concrete pumping over lifting it up in skips via a crane:
- Much larger volume of concrete placed per hour. A crane would be doing well lift 12m³ per hour. A Schwing Static Pump can pump over 50m³ per hour to the top of today's tallest high rise buildings.
- Constant flow. Today's Schwing Concrete Pumps can pump concrete as quickly as a truck mixer can discharge into them. Even as fast as two truck mixers can discharge in many situations.
- Fewer wasted man hours. The people placing the concrete need to wait for the next batch while the skip is in motion or being refilled at the bottom. The people at the bottom are just waiting for the skip to come back down while it is in motion or discharging at the top. The continuous flow from a concrete pump means less waiting around.
- The crane can perform other tasks. Instead of lifting buckets of concrete up and down, the crane can be employed to deliver steelwork, scaffolding, formwork and all the other necessary building material to where it needs to be.
- Concrete placed straight where you want it. The placing hose can be moved around so that concrete can be placed wherever it is needed. A Separate Placing Boom can also be employed to position the end hose exactly where it is needed within a large area. Mobile concrete pumps come with their own dedicated placing boom.
- Lower Labour Costs. Because the concrete can be placed exactly where it is needed, only a minimum of people are required to distribute the concrete - unlike when a skip dumps a load and people are needed to then move the concrete to where it is needed.
- Quicker setup times. A mobile pump can arrive on site, extend its outriggers and boom and be pumping concrete many floors up within an hour. It can even do two or even three such jobs in a day.
The Rock Valve
As demand grew for concrete to be pumped further and higher, the flat gate valve in use at the time could no longer cope with the pressures required and in 1982, Schwing patented the revolutionary "Rock Valve". This was able to work with far higher pressures, allowing the heights and distances for concrete pumping to be greatly increased. The high pressure in the Rock Valve system helps seal the valve rather than working against it.
The wide mouth of the Rock Valve also helps keep the system stable and is extremely low wearing due to the low friction design. The abrasive concrete is only scraping against one side of the valve at any one time, nearly halving the amount of wear compared to other designs.
Placing the concrete
Pumping the concrete is one aspect of the overall task. Another is controlling where the concrete is placed. Whilst this can be done by manually positioning the end hose, a remote-controlled articulated placing boom is often used to position the placing hose exactly where the concrete is needed. The robotic arm is designed to unfold is a small area and be able to reach every spot within the length of the boom. Even if there are difficult barriers and constraints in the area. The pipe runs the length of the boom and a placing hose on the end can be positioned to place the concrete precisely where it is needed, quickly and easily.
Types of Concrete Pumps
Other than capacity, the main difference between the various types of concrete pumps is determined by the additional equipment that comes as part of the pump. A concrete pump in its simplest form is best represented by a Stationary Concrete Pump. Additions to this, resulting in other types of concrete pump are:
- Transport - a dedicated vehicle to transport and position the pump,
- A Boom - a dedicated placing boom attached to the pump,
- and even a Truck Mixer - to store and supply the concrete.
A Mobile Concrete Pump, also known as a Truck Mounted Mobile incorporates both a concrete pump and a placing boom mounted onto a truck chassis. Mobiles come with booms ranging from less than 20 metres to ones which can reach heights of over 60 metres. The advantage of a mobile pump is that it can turn up at a job and be pumping concrete very quickly to anywhere within the range of the boom. This makes mobile boom pumps very popular on the widest range of construction projects, being able to pump at very high volumes quickly to wherever concrete is needed with minimum labour requirements.
A Static Concrete Pump, also referred to as a Stationary, Line Pump or Trailer Mounted Concrete Pump is mounted on a trailer and requires separate pipeline to be attached reaching to wherever the concrete needs to be placed. The pipeline is a series of steel or rubber pipes, known also as concrete placing hoses, linked together and manually attached to the outlet of the pump. The other end of the pipe could either be attached to a Separate Placing Boom, allowing the concrete to be placed with precision quickly over a wide area or it might just finish with a rubber placing hose for manual placement. A Static Pump needs to be towed or separately transported to jobs.
The advantage of a static pump is that the pipeline can be long so that the actual pump can be very far away from where the concrete is being placed; maybe hundreds of metres below or even kilometres away. This makes static pumps essential for tunnelling work and high rise constructions. Static Concrete pumps come in a far greater range of capacity than those used on Mobile pumps. From smaller pumps ideal for residential and low rise work right up to the SP8800 which can reach pressures up to 243 bar and pump over 100m³ per hour. It is a middle of the range SP4000 which holds the World Record for pumping concrete to the highest vertical distance. (The job also included a horizontal component of over 1km.) A pumping distance has yet to be found which cannot be done by a Schwing pump.
Truck Mounted Static Pump
A static pump can also be mounted onto a truck chassis but without a boom, resulting in a Schwing Truck Mounted Static Concrete Pump. These are perfect for the many quick jobs where a boom might not reach. It might be a slab for an extension at the back of a home or garden where running a pipeline through or round the building is the only option. A normal static pump would need to be towed or delivered on a Hiab truck but with the Truck Mounted Static Pump, the operator can drive it straight to site. Schwing Truck Mounted Static Pumps also come with storage for up to 100 meters of pipeline and other accessories so everything needed is in one place allowing the operator to pack up and head straight to the next job as soon as a work is completed.
Truck Mixer Concrete Pump
Another aspect of concrete placement is the supply of concrete. Both Mobile and Static Pumps have a large hopper to receive concrete from a truck mixer. However Schwing Stetter offers a mobile product which also carries a supply of concrete with it. The Fahrmischer Beton Pumpen (truck mixer concrete pump) combines not only a pump and boom but also the concrete storage and transport in the form of a mixer truck, all in one package.
Advantages of Schwing Concrete Pumps
Schwing offers a complete range of concrete pumps for sale with versatile machines to cover every application. There are numerous reasons to invest in a Schwing. Here is a list of the features and benefits that come with using Schwing concrete pumps:
- Precision German and US Engineering. You know you are getting high quality, well made equipment.
- Schwing's many decades of experience in concrete equipment design and production. You know your pump has proven reliability.
- Schwing invented today's standard hydraulic twin cylinder concrete pump. Your pump is designed and built by the people who know concrete pumps best.
- Schwing invented and patented the Rock Valve. At the heart of your pump is the best concrete valve available - but only if it's a Schwing.
- The Rock Valve provides low wear and dependability. More concrete pumped between servicing and ware parts replacement.
- Open hydraulic circuits leading to fuel efficiency. More concrete pumped per gallon of diesel.
- Robust outriggers offer maximum steadiness with minimum footprint. Schwing mobile pumps can set up safely in smaller spaces.
- Multi-functional yet logical electrical and remote controls. It's quick and easy to place concrete exactly where you need it.
- Qualified Schwing Stetter engineers are available on site. You can get help wherever you are in the UK.
- Spare parts are available from our extensive London warehouse. You will be up and running again quickly when you need parts.
- Schwing Stetter equipment's reputation for longevity. Your Schwing pump will hold its value so you can resell it later at a better price.
- Our dedication to providing the very best customer service possible. You won't be left in the lurch. We will do all we can to ensure you get what you need from us, when you need it.
- Customisation is available from our expert engineers. You can have your equipment adjusted to specification.
- We maintain pumps as well as sell them. When you buy your pump from Schwing, you are buying from the people who know your pump inside out - literally.
- We have a complete range of concrete pumps available - a pump for every application. No matter what, how or where you're pumping concrete, we have the equipment and expertise you need for the job.
- We offer a full range of complimentary equipment for concrete Batching, Transport, Placement and Recycling. No matter what you're doing with concrete, we have the equipment and experience to help make it a success.
From customers with a single concrete pump to the largest fleets in the world, Schwing Stetter has been bringing solutions along with value and success to the industry for many decades.
We supply the equipment, spare parts and servicing to concrete pump customers all over the UK as well as supporting our Batching, Transportation and Recycling plant customers, tunnel construction, foundation engineering and sludge handling.
The Schwing brand has been well-established in the market for 80 years and continues to be in the forefront of innovation in the design of Concrete Pumps. Our high quality concrete pumping equipment is manufactured in our own factories in Germany and the USA. Look at some of our key projects in the UK and Ireland to see examples of our Concrete Pumps in use.
For more information on Schwing Concrete Pumps, please contact us.
Schwing Concrete Pump Types
At Schwing Stetter UK we sell the full range of Schwing Concrete pumps. Have a look in more detail below at the type of pump you are interested in and always feel free to give us a call if you'd like more information.