Pin Brazing is a metallurgically safe and easy process of making electrical connections to metallic structures, such as steel and ductile iron pipelines, which are needed to be electrically earthed or cathodically protected. The pin brazing system has some major advantages over alternative systems. In this process, operator training and equipment maintenance should be of high standard.
The Process
The technique of pin brazing is based mainly upon electric-arc silver soldering using a pin brazing unit, a hollow brazing pin containing silver solder and flux. The pin brazing technique is well designed for joints between insulated pipe sections, installation of sacrificial anodes, connection to measuring cables, and bonding zinc bracelets to offshore pipelines. It provides high mechanical strength, extremely low resistance, and easy and fast installation. A large number of connections are required for anode cables, measuring posts etc, within a cathodic protection system. The pin brazing system is ideally suited to this.
History
A revolution in itself when first introduced way back in the 1950's, Pin brazing was basically developed to ensure safe & flawless electrical connection when applied to the varied types of steel structures, be it the attachment of rail bonds, joints between pipes, installation of sacrificial anodes, connection to measuring cables, test posts to name a few. Almost any electrical joint is possible within seconds by this automatic brazing method which has taken the industry by storm.
Cathodic Protection
Cathodic protection is a method to prevent a metal surface from corrosion by making that surface the cathode of an electrochemical cell. It is a technique, which is used to protect the bigger metal structures from corrosion. The cathodic protection systems are primarily used to protect water and structures from corrosion. The cathodic protection systems are primarily used to protect water and fuel pipelines and storage tanks, steel, steel pier piles, ships, onshore oil well casings and offshore oil platforms. It is an effective method of preventing stress corrosion cracking.
Pin Brazing for Cathodic Protection
Pin brazing easily attach the electrical cable connection over the joints, such as in the case of application of cathodic protection system to a pipeline with spigot and sleeve joints. It gets brazed at both the spigot and sleeve ends of the pipe and the cable attached. In case of pipes of ductile or cast-iron, one goes for threaded brazing pins application where a prefabricated cable with nuts is fastened. As for steel pipes, pin brazing either in the form of threaded brazing pins with nuts or cable is used. It gets brazed directly onto the pipe by means of a lug.
As we know, Cathodic protection controls the corrosion of any metal surface by simply transforming that particular surface into the cathode of an electrochemical cell. The system protects steel, water & fuel pipelines & storage tanks to name a few. Consisting vital units essential for providing safe cable connections as the availability of connections for anode cables, test posts et al in a cathodic protection system, pin brazing makes the task much easier. Apart from these, Pin brazing even acts as a welding generator such as a power source in situations where a great many connections need to be made in one place such as pipe coating yards, lay barges etc.
Advantages
There are innumerable advantages of using Pin brazing system because of its varied plus points which has made it one of the most sought after brazing solution. Let us take a look at the distinct salient features of Pin brazing.
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Speed of Connection. The pin brazing process is very fast and typipcally requires just one minute for any connection.
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Low Temperature. Both the low melting point of the solder (up to 650°) and short brazing time keep thermal effects on the metal to a minimum.
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All-Weather. Wind, rain and cold do not prevent the operator from working safely and effectively. Damp conditions pose no problem.
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Easy to Use. Operators can be trained to effectively maintain and use equipment in less than one hour.
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Versatile. The portable nature of the equipment means that connections can be made in almost any location above or below ground, even overhead!
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