#1 | 2019
SYN] Magazine
12/18

"This is structural transformation in practice!"

“Coalminers have become groundwater protection operatives. This is structural transformation in practice,” says foreman Markus Schneider at no. 3 shaft of the Auguste Victoria colliery in Marl. “Solutions like the new hydraulic flange spreader from Atlas Copco Tools will help us perform our future tasks safely and efficiently.”

140 tonnes of spreading force

Safe disconnection and alignment of flanged piping

Flanged joints need maintenance whether they are located on platforms high above chemical plants, at ground level in the process industry or more than 1,000 m below ground. New flange spreaders from Atlas Copco Tools make this key work on piping easier and improve ergonomics as this example from a colliery in the Ruhr area shows.

In Germany, underground coal mining came to an end last December. However, as 150 years of industrial coal mining have left deep traces, mine shafts cannot be simply filled in when mining comes to an end. “We are preparing for the post-mining phase,” says Dr. Stefan Roßbach, responsible for dewatering in the technical and logistics service department of RAG Aktiengesellschaft (formerly Ruhrkohle AG). “Every year, we pump about 65 million cubic metres of water out of active and abandoned mines,” the department manager reports. “This way, we prevent saline water from deep underground from rising in an uncontrolled way and penetrating the groundwater strata used for drinking water extraction.”

The Auguste Victoria colliery in Marl, where mining came to an end at the end of 2015, is one of 12 dewatering stations currently in operation. “From shaft 3, we pump water from a depth of 1,195 m to the surface and discharge it to the nearby river Lippe,” Roßbach reports. The water is currently fed via an extensive underground piping network to a pump chamber on the sixth level, from where it is pumped to the surface via a double piping system installed in the shaft.

The masters of the flanges

“The many kilometres of piping in the colliery have countless flanged joints. Our team must maintain these flanges and prevent leaks,” says foreman Markus Schneider, describing the key task of the dewatering team. Schneider says that there are so many flanged joints because each individual pipe needed to be taken down into the mine through the shaft. “You could say that shafts are the bottlenecks in a pit. This is why our pipe segments are considerably shorter than in piping on the surface.” He adds that the maintenance requirements are considerable and that the flanged joints are not always easy to reach for the replacement of gaskets.

“We tested the new spreaders from Atlas Copco Tools. These tools convinced us because of their ease of use and the high force available for the disconnection and alignment of piping strings,” the technician reports. 


Hydraulic spreaders reduce accident risks

Schneider says that it was a matter of luck whether you could separate the pipe ends manually, depending on the condition and diameter of piping and the space available in the mine. “Of course, you can use hoists or apply crowbars as levers, but if you slip, an accident report becomes almost inevitable,” he adds, warning of the risks of injury.

He says that the convenient ACHS 14-T flange spreader from Atlas Copco Tools is a safe alternative that requires considerably less force. The modular system consists of a compact pump connected to the spreader itself via a high-pressure hose. “The manual pump, which only weighs 4 kg, delivers a pressure of 700 bar, which is converted into a finely adjustable spreading force of up to 14 tonnes,” says Schneider. The entire equipment is supplied in a sturdy case. “You only need a gap of 6 mm to work on a flange, which is very useful,” Schneider reports. He says that this narrow gap is adequate for inserting the first stage of the graduated spreader wedges and offers the area of contact required.

For working in confined spaces, the fact that the full spreading force can be applied to each individual spreader wedge is very useful. “It is practically impossible for the graduated spreader wedges, which are made to provide a tight fit, to slip out of the gap,” says the maintenance expert, underlining another key advantage. “The parallel movement of the wedges prevents scratching and damage to the flange surfaces of the type which can always occur if you use conventional crowbars.”

In addition to the hydraulic tool, Atlas Copco Tools also has a purely mechanical flange spreader in its range (ACSM 08-T). In this case, the spreading force is generated by a torque wrench instead of a manual pump. This compact unit allows the miners to develop a spreading force of eight tonnes without significant effort. “However, six tonnes more force are very useful, especially with our big pipes. That’s why the ACHS 14-T is our favourite.”

A never-ending task

To provide long-term protection for groundwater resources, RAG Aktiengesellschaft will have to monitor underground water and transfer it safely to the surface for many years. Schneider sums up the changing tasks of his colleagues: “Once we were miners who produced coal. No we have become groundwater protection operatives.” He takes his leave with the traditional miners’ greeting of “Glück auf!”