Nearly 20,000 lbs. of Shield Arc 80 electrodes were used on an Alaskan pipeline welding project in Prudhoe Bay.

The offshore line is laid at sea depths ranging from 3 to 40 feet. The pipe-line lies a minimum of 7 feet below the floor of the ocean. Pipe was welded in heated tents and then laid through a slot cut in the sea ice by special trenching machines.

As one of its tools, Houston Contracting selected Shield Arc 80 welding electrode, supplied by Lincoln Electric Co. of Cleveland. The Shield Arc 80 is an 80,000-psi tensile strength consumable that is designed especially for pipeline welding. Each diameter of the Shield Arc 80 was manufactured from one heat of steel and under controlled chemical composition—both of the steel core wire and the coating mixes.

Before leaving the Lincoln Electric facility, the electrodes were tested for weld metal mechanical properties and soundness. The manufacturer also determined that the electrodes fell within the acceptance range of American Welding Society specifications. The electrodes were certified to American Welding Society A5.01 shielded metal procurement guidelines and A5.5 specification for low-alloy steel electrodes for shielded metal arc welding.

Hermetically sealed cans and special packaging were used to ship the electrodes to Alaska for CTOD (crack tip opening displacement) testing. This test includes simulating field welding conditions using liquid nitrogen to cool the pipe and then applying torsional flex tests. In total, Lincoln shipped nearly 20,000 pounds of electrodes in three diameters (3.2, 4, and 5 mm) for the project.

The injection-molded plastic impact beam, made of Xenoy polycarbonate/polybutylene terephthalate, supplied by GE Plastics of Pittsfield, Mass., replaces what is typically a stamped steel shell. The beam fits snugly against the inside surface of the fascia, giving a stiff feel and providing support for step loading. Attachment holes and locators, for snapping in the step pads, are molded in, which eliminates the need for secondary operations. The mass of the beam is 4.5 kg, compared with 11.5 kg for a typical stamped steel shell.

The molded-in-color thermoplastic polyolefin fascia eliminates the cost of painting, as well as peeling, fading, and dulling. The plastic's flexibility enables it to resist dents and dings under minor impacts. The 3.2-kg injection molded part has five gate openings, and was filled with a sequential valve-gating system to reduce knit lines.

The bumper provides a top surface area to step on. The replaceable step pads, also of thermoplastic polyolefin, protect the top surface of the fascia. The 4-kg step pads are self-retaining through molded-in snap retainers on the underside surface. The step pads have retainers that pass through the holes in the fascia and then snap into molded-in holes on the top surface of the plastic beam. The step pads also hold the cover to the beam.

The steel hitch plate provides towing capability and adds stiffness and strength to the bumper. The frame brackets (3.6 kg), beam brackets (3 kg), and hitch plate (7.3 kg) are made of high-strength, low-alloy steel to provide a solid system for trailer towing.

The hybrid bumper's structural components are claimed by Ford to be lighter by about 2 kg than comparable stamped steel designs. The step bumper passed the 4-km/hr. barrier and pendulum impact test without damage to the vehicle or the bumper system itself. It also provides rigid support for step loading, while incorporating Class II towing (350-lb. maximum tongue load and 3,500-lb. maximum gross trailer weight) capability.

A modified assembly lowers the weight and controls vibrations of an exhaust system by up to 50 percent compared to conventional ones.

Conventional exhaust systems are suspended by soft rubber hangers, which allow the system to move freely to accommodate engine vibration, vehicle movement, and thermal expansion. Because only a few points support the entire system, it must have a great deal of mechanical strength to resist bending and torsion. The mechanical strength requirement dictates the material thickness of the system's pipes, endcaps, and shells.

Bosal's Light Weight design attaches the mufflers and resonators to fixed brackets that are bolted to the underfloor. In place of the flexible rubber hangers, the exhaust system is fixed to the underfloor with solid rubber blocks, which hold the muffler to the underbody more tightly, according to Piet Steenackers, director of advanced research for Bosal International in Lummen, Belgium. Bosal replaced traditional single-flex joints with double-flex joints that provide a better decoupling of the exhaust system from engine vibrations.

The rubber blocks hold the exhaust system to the underbody more tightly, limiting movement from vibration and acceleration to just 1 to 2 mm, said Steenackers, compared to 2 cm or so with conventional exhaust systems. The sturdier attachment allows thinner and lighter components to be used, as well as larger muffler volumes, he noted.

Because the Light Weight exhaust system has minimal movement, the space between it and the vehicle underfloor can be relatively small, allowing larger muffler volume without losing interior space. "On a silencer of 5 cm in diameter, if you can add 1 cm on the radius, you have an enormous amount more volume," said Steenackers. In addition, the double-flex joint helps to reduce vibration levels that are propagated down into the exhaust by about 10 decibels. Interior noise levels are comparable to conventional exhaust systems, according to the company.

The premier issue of IRT's Industrial Reports examined No. 50 steel roller transmission chain. IRT's lab stretched six brand-name chains statically, then ran them on an endurance tester. The report ranks the chains by the amount each stretched after 600 hours on the endurance machine. Chains ran unoiled except for what had been applied initially at the factory.

Schwartz said IRT operates as a virtual company, calling upon 50 employees and consultants as needed, many of whom have served on national standards boards. Industry veterans bring forth their testing and product knowledge as Industrial Reports examines air cylinders, plug-in relays, bearings, V-belts, or air valves—all of which are slated for testing soon.

Industrial Reports accepts no advertising and operates without any links to suppliers, industry groups, or trade associations. The reports are written in a clear, unassuming style. "Our readers are interested in which brands performed the best," Schwartz said. "Although we can test for why products fail, we prefer to know which ones do and how they compare to each other."

The company decided to overcome the problem by welding the bearing to the turbine wheel. Using a SureWeld 20 ultrasonic plastic welder, supplied by Sonobond Ultrasonics of West Chester, Pa., the company was able to attach the bearing to the turbine wheel, creating a strong molecular bond. "Ultrasonic welding with the SureWeld 20 causes the materials to become one," said Herlehy. "Now the bearing doesn't move within the assembly, so the jamming problem has been eliminated."

Polaris Pool Systems uses ultrasonics to weld a bearing into a turbine wheel assembly.

Ultrasonic welding technology transmits vibrational energy to the interface of the plastic parts being joined. The energy causes the plastic to soften for a fraction of a second, forming a bond when it solidifies. Sonobond Ultrasonics supplied a customized welding horn and fixtures specifically for the Polaris application. The welding equipment eliminated the slippage problem and also aligned the welded parts. Average weld time of the part is only 0.3-0.4 second. SureWeld units use a 1,000- to 3,000-watt power supply.

Polaris is considering the use of ultrasonic welding to speed up the production of other components as well. The company is testing a prototype, developed by Sonobond, to produce the wheel and pulley assembly, which until now have been joined with adhesives. "Converting to ultrasonic energy will reduce costs and production time," said Herlehy.

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