Category: WELDING

WELDING, Welding Engineer2 Comments

WPS/PQR – JOINT DESIGN

Amarine Antonio

Definitions: Welding Groove Design & Bevel Preparation What is Backing in welding What is Back gouging in welding What is Retainer in welding What is CJP, PJP in welding What is Buttering in welding, In Situ Buttering AWS D1.1: Non-Tubular vs Tubular and how to prepare the PQR WPS Codes/Specifications  references for crosscheck the essential variables applied to write WPS/PQR: AWS D1.1: WPS variables – Joint design ASME IX: WPS variables – Joint design EN ISO 15614: WPS variables – Joint design API 1104: WPS variable – Joint design End Product Design Codes Notes on Welding WPS: ASME 31.3 (Process … Continue reading WPS/PQR – JOINT DESIGN

WELDING, Welding Engineer1 Comment

Welding Work Clamp (Return line)

Amarine Antonio

Work Clamps The work clamp must be the correct size for the current being used, and it must clamp tightly to the material. Heat can build up in the work clamp, reducing welding efficiency. Power losses in the work clamp are often overlooked. The clamp should be touched occasionally to find out if it is getting hot. In addition to power losses due to poor work lead clamping, a loose clamp may cause arcing that can damage apart. If the part is to be moved during welding, a swivel-type work clamp may be needed, It may be necessary to weld … Continue reading Welding Work Clamp (Return line)

WELDING, Welding Engineer2 Comments

Welding Cable or Lead set-up

Amarine Antonio

The terms welding cables or welding leads are used to mean the same thing. Cables used for welding must be: 1- Flexible 2- Well-insulated 3- Correct size for the job. Most welding cables are made from stranded copper wire. Some manufacturers sell a newer type of cable made from aluminum wires. The aluminum wires are lighter and less expensive than copper. Because aluminum as a conductor is not as good as copper for given wire size, the aluminum wire should be one size larger than would be required for copper. The insulation on welding cables will be exposed to hot … Continue reading Welding Cable or Lead set-up

WELDING, Welding Engineer1 Comment

What is Duty Cycle in Welding

Amarine Antonio

The duty cycle is the percentage of time a welding machine can be used continuously. Most SMA welding machines cannot be used 100% of the time because they produce some internal heat at the same time that they produce the welding current. SMA welders are rarely used every minute for long periods of time. The welder must take time to change electrodes, change positions, or change parts. The duty cycle of a welding machine increases as the amperage is reduced and decreases as the amperage are raised. Most SMA welding machines weld at a 60% rate or less. Therefore, most … Continue reading What is Duty Cycle in Welding

WELDING, Welding Engineer1 Comment

Welding Arc Blow Causes & Remedies

Amarine Antonio

Arc Blow is the deflection of arc from its normal path because of magnetic forces. When electrons flow, they create lines of magnetic force that circle around the path of flow. These lines of magnetic force are referred to as magnetic flux lines. They space themselves evenly along a current-carrying wire. If the wire is bent, the flux lines on one side are compressed together, and those on the other side are stretched out. The unevenly spaced flux lines try to straighten the wire so that the lines can be evenly spaced once again. The force that they place on the wire is usually … Continue reading Welding Arc Blow Causes & Remedies

WELDING, Welding Engineer2 Comments

Typical Welding operating Voltage

Amarine Antonio

Operating, welding, or Closed-circuit voltage, is the voltage at the arc during welding. Operating voltage is much like the water pressure observed as the water hose is being used. The operating voltage will vary with arc length, type of electrode being used, type of current, and polarity. The welding voltage will be between 17 and 40 V. What if Operating Voltage is too High? –> See:Welding Voltage & Arc Length Relationship Continue reading Typical Welding operating Voltage

WELDING, WELDING METALLURGY2 Comments

What is OCV Open Circuit Voltage Maximum value

Amarine Antonio

Open Circuit Voltage Open circuit voltage is the voltage at the electrode before striking an arc (with no current being drawn). The open-circuit voltage is much like the higher surge of pressure you might observe when a water hose nozzle is first opened. It is easy to see that the initial pressure from the garden hose was higher than the pressure of the continuous flow of water. The open-circuit voltage is usually between 50 and 80 V. The higher the open-circuit voltage, the easier it is to strike an arc because of the initial higher voltage pressure. Additional question? What is … Continue reading What is OCV Open Circuit Voltage Maximum value

WELDING, Welding Engineer2 Comments

Welding Power Types CC, CV, RAV

Amarine Antonio

Welding power can be supplied as three typical types as below: ■ Constant voltage (CV)—The arc voltage remains constant at the selected setting even if the arc length and amperage increase or decrease. ■ Rising arc voltage (RAV)—The arc voltage increases as the amperage increases. ■ Constant current (CC)—The total welding current (watts) remains the same. This type of power is also called drooping arc voltage (DAV) because the arc voltage decreases as the amperage increases. The shielded metal arc welding (SMAW) process requires a constant current (CC) arc voltage characteristic, illustrated by the constant current line. The shielded metal arc … Continue reading Welding Power Types CC, CV, RAV

WELDING, Welding Engineer3 Comments

Welding Current Types DCEN, DCEP, AC

Amarine Antonio

There are three different types of current used for welding are alternating current (AC), direct-current electrode negative (DCEN), and direct current electrode positive (DCEP). The terms DCEN and DCEP have replaced the former terms direct-current straight polarity (DCSP) and direct-current reverse polarity (DCRP). In other words, DCEN and DCSP are the same currents, and DCEP and DCRP are the same currents. Some electrodes can be used with only one type of current. Others can be used with two or more types of current. Each welding current has a different effect on the weld. DCEN – Use for GTAW, SMAW- Root or … Continue reading Welding Current Types DCEN, DCEP, AC