Welding Terms (A&B)

Dear Readers,

Following terms are commonly used in Welding works. 

Arc Blow – The deflection of an electric arc from its normal path because of magnetic forces.

Arc Cutting – A group of thermal cutting processes that severs or removes metal by melting with the heat of an arc between an electrode and the work piece.

Arc Force – The axial force developed by an arc plasma.

Arc Gouging – An arc cutting procedure used to form a bevel or groove.

Arc Length – The distance from the tip of the electrode or wire to the work piece.

Arc Time – The time during which an arc is maintained.

Arc Voltage – The voltage across the welding arc.

Arc Welding – A group of welding processes which produces coalescence of metals by heating them with an arc, with or without the application of pressure and with or without the use of filler metal.

Arc Welding Deposition Efficiency (%) – The ratio of the weight of filler metal deposited to the weight of filler metal melted.

Arc Welding Electrode – A part of the welding system through which current is conducted that ends at the arc.

Atomic Hydrogen Welding – An arc welding process which produces coalescence of metals by heating them with an electric arc maintained between two metal electrodes in an atmosphere of hydrogen.

Autogenous Weld – A fusion weld made without the addition of filler metal.

Automatic – The control of a process with equipment that requires little or no observation of the welding and no manual adjustment of the equipment controls.

Back Gouging – The removal of weld metal and base metal from the other side of a partially welded joint to assure complete penetration upon subsequent welding from that side.

Backfire – The momentary recession of the flame into the welding or cutting tip followed by reappearance or complete extinction of the flame.

Backhand Welding – A welding technique where the welding torch or gun is directed opposite to the direction of welding.

Backing – A material (base metal, weld metal, or granular material) placed at the root of a weld joint for the purpose of supporting molten weld metal.

Backup Strip — is a strip or section of steel butted up to an open gap between two pieces of steel.

Backing Gas – A shielding gas used on the underside of a weld bead to protect it from atmospheric contamination.

Back-Step Sequence – A longitudinal sequence in which the weld bead increments are deposited in the direction opposite to the progress of welding the joint.

Base Metal (material) – The metal (material) to be welded, brazed, soldered, or cut. See also substrate.

Bead - the deposited filler metal on and in the work surface when the wire or electrode is melted and fused into the steel. A stringer bead is a narrow bead with only a dragging motion or light oscillation, while a weave bead is wider with more oscillation.

Bend Radius – Radius of curvature on a bend specimen or bent area of a formed part. Measured on the inside of a bend.

Bevel – An angled edge preparation.

Blown-up - what you will be if you weld or cut on containers with fumes. NEVER weld or cut on any container unless it is new or you know it has been cleaned and safety certified! Containers can be toxic, flammable, or explosive.

Braze Welding – A method of welding by using a filler metal, having a liquidus above 840 °F (450 °C) and below the solidus of the base metals.

Brazing – A group of welding processes which produces coalescence of materials by heating them to a suitable temperature and by using a filler metal, having a liquidus above 840 °F (450 °C) and below the solidus of the base materials. The filler metal is distributed between the closely fitted surfaces of the joint by capillary attraction.

Burr – A rough ridge, edge, protuberance, or area left on metal after cutting, drilling, punching, or stamping.

Buttering – A form of surfacing in which one or more layers of weld metal are deposited (for example, a high alloy weld deposit on steel base metal which is to be welded to a dissimilar base metal). The buttering provides a suitable transition weld deposit for subsequent completion of the butt weld on the groove face of one member.

Butt Joint – A joint between two members lying in the same plane.

Busted Out - failing a weld test because of defects in the welds. "He busted out on his test plates and didn't get hired."

For More Details about Electrode Classification Click Here

For More Details of TIG Welding Click Here

For More Details of Stick Welding Click Here

For More Details of Welding Symbol Click Here

Introduction of FRP Pipe

Dear Readers,

The Expansion of FRP is fiberglass-reinforced plastic which is a composite material consisting of thermoset resin and fibre reinforcement. FRP is principally made up of thermoset resin and glass Fibers. Resins can be divided into two broad classes: thermosetting and thermoplastic. Thermosetting resins cure to produce an infusible solid material that does not melt when heated. They soften when heated above their glass transition temperature, but do not reach a liquid state. Thermosetting resins used for FRP are typically purchased in liquid form and are reacted to a solid with chemical additives.

FRP is a reliable material of construction for piping and equipment in acid and base chemical services, such as hydrochloric acid (HCI), sulfuric acid (H₂SO₄), Chlorine dioxide (ClO₂), sodium hypochlorite (NaOCI) and caustic (NaOH) solutions.

Compared to most metals, FRP is generally considered a non-ductile material. FRP has a long elastic zone and markedly lower modulus of elasticity as compared to carbon and stainless steel. It should be noted that since FRP is a composite material, its material properties are orthotropic in nature, meaning that the properties are different in the hoop and axial directions.

Pipes can be manufactured by contact moulding (Hand lay-up) or hand lay up in combination with filament winding.

Types of glass fibre reinforcements

1. Chopped Stand Mat (CSM)

2. Rovings

3. Woven glass fabrics

4. Surface Veil

They are manufactured from glass or synthetic fibres such as polyester.  

A wide range of process equipment is constructed from FRP to meet the service conditions including Chlorine dioxide generators and storage tanks, bleach towers, Effluent Piping, Process Piping, Sump, and trough linings. FRP piping system is available in a wide range of sizes starting from 1 inch to 144 inches.

FRP Pipes are light Weight and Non-Corrosive and easily constructed, it is up to 75% less than Steel weight but it is equally strong. Density of FRP composite is 1800 Kg/Cum, Where as Carbon Steel is 7860 Kg/Cum.

Moisture Separator

Moisture separators are devices used in air compressors to remove moisture from compressed air. Since, moisture in compressed air can cause several problems, such as corrosion of tools and equipment, freezing of pipes, and reduced efficiency of the compressor itself. They are employed by several industries, including automotive, food and beverage, pharmaceutical, and textiles. Moisture separators are typically used in systems where compressed air is stored in an air receiver.

They can also help to improve the efficiency of air compressors and other equipment by removing water from the compressed air. Moisture separators are available in various sizes and configurations to suit different applications.

Dehydration is the preservation technique that attempts to remove moisture. The prefix de refers to removing or eliminating, the root word hydra refers to water, and the suffix ion refers to a process, thus making dehydration the process of removing or eliminating moisture or water.

Separators work on the principle that the three components have different densities, which allows them to stratify when moving slowly with gas on top, water on the bottom and oil in the middle. Any solids such as sand will also settle in the bottom of the separator.

There are three types of Moisture separators:

1. Water Separator

2. Moisture Separator

3. Moisture Separator with Filter

First, they are highly effective at removing water vapor from compressed air. Second, they are relatively easy to install and maintain. Third, they are relatively inexpensive to operate. Finally, Moisture separators can be used in various climates and applications.

It is used to protect equipment that can be damaged by contact with moisture, such as pneumatic tools and cylinders, and to improve the equipment’s efficiency by removing unwanted water vapor.