BOLTED

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bolt securing

Installing a Bolt Tensioner from Boltight

Designed with the benefit of more than 30 years experience in the field, Boltight has created a range of tools to meet the challenge of today’s bolt tensioning requirements.

Just watch how easy it is to install these tensioners!

► Click here for more information about Boltight

No more loose screws on giant quay cranes

29 November 2017
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Text: Roxana Ortiz

photo: Paceco

First published in Bolted #2 2017.

CUSTOMER: PACECO ESPAÑA S.A
PRODUCTS: QUAY CRANES, YARD CRANES, SERVICES AND SYSTEMS FOR CONTAINER HANDLING
ESTABLISHED: 1967
SHAREHOLDERS: MITSUI GROUP AND URSSA, S. COOP.
NORD-LOCK PRODUCT: NORD-LOCK 20 / NL20

Offering cranes, services and systems to the container-handling industry, engineering company Paceco España (Spain) must adjust to its customers’ needs. As ships get bigger, quay and yard cranes must increase height and reach, while also becoming more efficient. Today, Paceco España can load and offload ships from 25 container lines. The company currently produces one of the largest and most efficient cranes on the market, the Portainer Malaccamax, which maximally offers a 72.5-metre outreach, a 52.5-metre clearance under spreader, and a 30.48-metre rail span.

Paceco España first connected with Nord-Lock in 2009, when there was a problem with one of the company’s quay cranes. The crane, with a 65-ton load capacity, had problems with the fixing of the gantry reducers – the gearboxes that move the quay crane along the dock. During operation, the fixing screws vibrated loose.

During their problem analyses, Paceco España’s engineers connected with Nord-Lock and when it presented a solution, Paceco España was pleasantly surprised. “We have been using their washers since 2009, and haven’t had any problems with bolted connections being subject to vibrations since then,” says engineer Pelayo Bobes. “With Nord-Lock washers, we have been able to provide total customer satisfaction and in turn saved both money and time.”

Understanding the markings on nuts and bolts

First published in Bolted #2 2017.

Q: What do the markings on bolts and nuts mean?
A:  Bolt heads and nuts are often marked with numbers, letters, dashes, slashes, dots, or an assortment of other marks. Fasteners commonly have two different markings: a unique manufacturer identification symbol – such as letters or an insignia – and information about the fastener strength. Such markings differ based on how the fasteners were made. See the table for the alloyed steel metric and stainless-steel metric fasteners that comply with ISO standards. UNC thread fasteners mainly comply with ASTM standards.

Due to lack of space, markings can be missing on smaller sizes, such as those with diameters below M5 according to ISO 898-1. However, the bolt class must be marked on the head above this size.

 

ASK THE EXPERTS
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Q: What do the markings on bolts and nuts mean?
A:  Bolt heads and nuts are often marked with numbers, letters, dashes, slashes, dots, or an assortment of other marks. Fasteners commonly have two different markings: a unique manufacturer identification symbol – such as letters or an insignia – and information about the fastener strength. Such markings differ based on how the fasteners were made. See the table to the right for the alloyed steel metric and stainless-steel metric fasteners that comply with ISO standards. UNC thread fasteners mainly comply with ASTM standards.Due to lack of space, markings can be missing on smaller sizes, such as those with diameters below M5 according to ISO 898-1. However, the bolt class must be marked on the head above this size.

ASK THE EXPERTS
Do you have a question about bolt securing?
Put the Nord-Lock experts to the test.
Email your questions about bolt securing to
experts@nord-lock.com

Hydropower: Relying on Superbolt for 30 years

1 November 2017
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Text: Chad Henderson

photo: John Kelly

When it comes to long-term Superbolt users, American Mike Bruno is hard to beat. More than 30 years ago, he was involved in one of the earliest installations of Superbolt tensioners in a hydropower turbine. Today, he continues to praise the performance of these tensioners. Here, he shares some inspirational insights.

First published in Bolted #2 2017.

You first worked with Superbolt tensioners at Diablo Dam in 1984. How did that come about?
“I was a machinist working at Seattle City Light, the electric utility for Seattle. We worked out of the machine shop down there, and we would go up and be labour support at Diablo Dam. In 1984, they were doing a stator-rotor inspection on the turbine, so they had to remove the rotor; that involves taking the thrust bearing apart, which is mounted on the turbine shaft. It is very important that the thrust block is perpendicular to the shaft within less than one-thousandth of an inch. Otherwise, it will have run-out and wobble.”

How did the Superbolt tensioners help with that?
“Back then, to get the right tension in the bolts, you had to heat the bolts so they would elongate, do the installation, and then wait for them to cool overnight. If the thrust bearing wasn’t sitting right on top of the shaft, you had to do it all over.

“The engineers at Diablo Dam had been in contact with Superbolt, and they modified the bolts so you didn’t have to go through this long process. Instead, we could tighten up those little bolts. If the thrust bearing wasn’t exactly perpendicular, you just tweaked the bolts on the opposite side. It was a very labour-saving modification.”

Today, you work at Wells Dam. What do you do there?

“I’ve been with the Wells Hydroelectric Project for about 17 years, managing and monitoring the project. What I’ve always enjoyed about my work is that every day there are new challenges or something that you’ve got to fix. We’ve got air systems, electrical systems, mechanical systems, hydraulic systems – all these different auxiliary systems that feed the turbines that run 24 hours a day.”

How has the dam been modernized over the years?
“One of the ways that it has been modernized is that we have installed PLCs on the majority of our alarm systems. Today, we have over 2,500 alarm points on different systems. This allows us to set more parameters for the alarm points, and we can also trend over time and compare with different machines. If something is starting to fail, you can set up a parameter to get an alarm so you can look into it before the failure actually happens.

“We are also using Superbolt tensioners when rebuilding our turbines. They’re being used in the load screws that hold the turbine bearing shoes in place, and in our turbine’s outer head cover, where you can’t access the bolts with a big wrench because it’s close quarters. They’re very reliable.”

FACTS: MIKE BRUNO
TITLE: Project Superintendent, Wells Hydroelectric Project, Douglas County Public Utility district
AGE: 60
LIVES: Chelan, Washington
BACKGROUND: Has a degree in industrial technology from Shoreline College; also studied at Cogswell College. Worked at Seattle City Light as a hydro machinist and foreman until 1990, then as a mechanical supervisor for the Skagit River Hydroelectric Project until 2000. Since then with Wells Hydroelectric Project.
PASSION: Married with three grown daughters, two granddaughters. Enjoys bow hunting and playing golf.

Hydraulic tensioning tool for nuclear reactor pressure vessel

Doosan Heavy Industries & Construction required a bolt tensioning solution to tighten nuclear reactor pressure vessel stud bolts. Boltight was contacted to design a hydraulic tensioning tool to achieve a predetermined bolt elongation, without exceeding the reactor head’s maximum allowable bearing stress.

The required bolt load was critically high (14,500 kN), and the space envelope was very small – the radial space available to install and operate the tensioner was particularly tight.

A tensioning system was designed to accommodate this high preload capacity within the space available. In realising these tools, Boltight engineers also incorporated a hydraulic piston retraction function into the design; to enable the equipment to be reset quickly, reducing operator fatigue. To compensate for dynamic joint behaviour, a spherical reaction nut and piston interface was integrated to accommodate any bending effects in the event of flange rotation.

Various safety mechanisms were incorporated to protect both the tools and the operators. Pressure relief valves were installed, and a floating gearbox design was engineered to avert damage should nut misalignment occur. The gearbox directly interfaced the geared nut which negated the need for a costly, heavy socket, and provided the necessary torque to rotate the nut.

Boltight were able to supply a complicated, bespoke design to exacting standards and achieved the tight delivery period set down by the client.

► Watch: Installation of Boltight bolt tensioner

Superbolt: Improving steel mill safety and productivity

18 October 2017
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Text: Keisuke Okada & Nic Townsend

First published in Bolted #2 2017.

SAFETY. The JFE Steel Corporation’s West Japan Works is one of the largest and most advanced steel mills in the world. Like all steel plants, the operating conditions are exceptionally demanding on machines and equipment, and potentially hazardous for personnel – especially the hot rolling mill, where molten steel is flattened and stretched into thin sheets. The temperature of the steel will reach at least 450°C (842°F).

Until recently, the fasteners that connected the decelerators and pinion stands on the hot rolling mill, were tightened using a 300-kg weight, which was suspended from the ceiling via a crane. The weight would be pulled from a makeshift scaffold, before letting it hit the wrench like a hammer. Overall, the procedure involved five people: three to pull the weight, one to fasten the wrench, and one to operate the crane. It took an hour to tighten each bolt, and the multiple safety risks for the personnel involved were considerable.

Switching to Superbolt multi-jack tensioners has turned one of the riskiest maintenance tasks in the plant into one of the safest. Each connection can now be secured by one person in just 15 minutes. With eight bolts on each mounted application, the overall reduction in downtime and increase in productivity is significant.

In fact, Superbolt multi-jack tensioners have proven so successful that they have been implemented in JFE Steel’s other hot rolling mills in Fukuyama and Chita.

Watch: Superbolt multi-jackbolt tensioners explainer video

Creating big opportunities for small distributor

11 October 2017
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Text: Alastair Macduff

photo: Nord-Lock Group, Viggo Bendz

Danish company Viggo Bendz has recently started supplying Stena Recycling with the Expander System for their grab machines - a potentially lucrative development for a small independent operator.

First published in Bolted #2 2017.

As prices continue to be down in the steel and metals industries, developing a successful partnership with a major customer can go a long way to securing profitability for a small business. The Danish company Viggo Bendz is based in Høng, on the west coast of Sjælland, the largest and easternmost of Denmark’s islands. The company employs eight people and delivers solutions and equipment for crushing, demolition and sorting. Poul Erik Jakobsen is owner and CEO. He took over the running of the business in 2006, just three years after it was formed. “When I started,” he says, “we were mainly dealing with excavators. Then one day I had a realization that the company would not survive in the future if we only sold certain kinds of bolts. We needed to expand our range in order to compete.”

The ability to anticipate change has been important to Viggo Bendz from the outset. Currently, one half of their business is parts for excavators such as teeth, buckets, cutting edges, hydraulic hammers and grabs. However, the other 50 per cent of their turnover comes from machines and complete plants for the environment and recycling business. Contractors are the main users of the Expander System bolts that they distribute, yet they have been well aware of Expander System’s potential in the recycling business, where Stena Recycling is one of the main players.

Located in five markets – Sweden, Denmark, Norway, Finland and Poland – Stena Recycling is committed to sustainability in their business practice. The two companies have had a long relationship, with Viggo Bendz supplying standard bolts for over a decade. However, they recently offered Stena Recycling the Expander System to test on their so-called ‘orange peel grabs’ (see picture). With this kind of machinery subject to wear and tear through constant and prolonged use, Stena Recycling have now taken the opportunity to employ a solution that will reduce the need for maintenance and will increase the safety and machine life cycle, Jakobsen believes. He says that, “By introducing the Expander System, Stena Recycling is saving money. Because of the quality, it represents a long-term investment for them. The industry is tough at the moment, due to the market price for steel and metals. Longer machine life obviously means both greater sustainability and profitability.”

The importance of supplying a sustainable solution to today’s market is something that Viggo Bendz knows well. The waste recycling business is one segment that is at the forefront of sustainable work practices, as companies increasingly focus on resource management and turning waste into new raw materials. More organizations are looking toward employing technology that en­ables this process and fits in with their sustainability strategy. Being able to supply a pivot solution that improves the durability and longevity of moving mechanical parts, means contributing something vital to the business of customers and to the environment as a whole.

As for being a smaller independent company in the current business climate, there are significant advantages according to Jakobsen. “We are focusing on quality products, which means that it is not always the cheapest solution for the customer. It is vital to us that we provide excellent service. Because of our size, we can be flexible and change direction quickly to help our customers and our own business if we need to.”

Being a distributor for the Expander System suits Viggo Bendz’ business model. They have a market presence all over Denmark, covering industries such as construction, mineral and scrap recycling. Currently Expander System accounts for around 200,000 euros of their annual turn­over. Like almost every modern business, raising the company’s profile nationally has meant increasing their online presence. “We are focusing a lot on social media now,” continues ­Jakobsen. “Once a week we try to upload a case story to Facebook. Every time we upload an Expander System case, we get a couple of new customers. This is something that we must continue to use to our advantage.”

With pricing being crucial to compete succesfully in the market for the foreseeable future, Viggo Bendz is both positive and pragmatic about its current position. “Yes, it is all about price,” Jakobsen says. “However, with Expander System we do not have so many direct competitors. Being able to offer reliable, long-term solutions gives us the chance to target customers in waste recycling and other sustainable businesses. Even travelling around locally, you see how many grabs and different machinery are in operation. This potential is exciting for us.”

FACTS: THE SOLUTION
CLIENT: Viggo Bendz.
END CUSTOMER: Stena Recycling.
LOCATION: Denmark.
PROJECT: To provide solution for pivot wear on grab machinery.
NORD-LOCK GROUP PRODUCT: The Expander System.

BENEFITS GAINED:

  • Longer machine life.
  • Less maintenance.
  • Improved reliability.
  • Increased uptime.

 

The Expander System: cost-effective and sustainable

With its focus on sustainability and cost-efficiency, the waste recycling industry is tailor-made for long-term bolting solutions. Grab machines work constantly and repetitively, collecting, sorting and distributing waste of all kinds. Naturally, they develop pivot wear over time. Standard bolt fittings and joints become worn, leading to enforced machine reparations, which in turn lead to downtime.

The difference with the Expander System is that it is installed directly into the existing mounting on the machines, and involves a simple process which avoids welding and line boring. As well as being cost-effective in terms of longer machine life and increased uptime, it also adheres to sustainability principles, requiring less equipment and repeated repairs. By prolonging the lifetime on cylinder rod ends and moving mechanical parts, Expander System contributes to the increased safety and productivity of hard-working grab machinery.

The Expander System is installed on over 10,000 types of machines, covering more than 80,000 different pivot applications so far. The most common industries where they are being used are construction, manufacturing, oil & gas, mining, marine and agriculture.

Within waste recycling, The Expander ­System is not the only Nord-Lock Group solution to be hard at work. Several companies currently employ Nord-Lock Group products, including large UK waste services company Biffa. They have been using the wheel nuts on all their Mercedes trucks since 2012, having found them safer, more reliable and cheaper to source than standard locking wheel nuts.

Find out more about Expander System

Watch: “Are you getting the most out of your machinery?”

 

Matching washers and bolts of different materials

First published in Bolted #2 2017.

Q: Can I use Nord-Lock stainless steel washers with steel bolts?

A: You can, as there is no difference in thread pitch between steel and stainless steel bolts. However, it is always best to use the same material for all parts of the joint. If you use a stainless steel washer together with high-strength fasteners of grade 10.9 or 12.9, you might deform the washers. These are only surface-hardened, and with a very high pre-load, the softer inside might incur “plastic deformation”. Steel bolts of grade 8.8 or lower might work in many applications, since the mechanical strength of grade 8.8 is similar to the one for stainless steel washers.

Another important aspect to consider when designing a bolted joint, including stainless steel washers and steel bolts, is corrosion, especially so-called galvanic corrosion, which may reduce the product life dramatically. Galvanic corrosion damage is induced when two dissimilar materials are coupled in an electrolyte. When a galvanic couple forms, one of the metals becomes the anode and corrodes faster than it would by itself. The other material becomes the cathode and corrodes slower than it would alone. Nord-Lock steel washers with Delta Protekt coating use the principle of controlled galvanic corrosion. Zinc material in this coating protects the cathode (the washer steel material).

 

ASK THE EXPERTS
Do you have a question about bolt securing?
Put the Nord-Lock experts to the test.
Email your questions about bolt securing to
experts@nord-lock.com