What Is PPE For Welding?
Personal Protective Equipment (PPEs) is a universal term for the clothing and equipment used to protect the welder from heat, sparks and flames.
Welding safety is important, and proper PPE will help you protect yourself from injury. Following these guidelines is the most effective way to ensure that you are safe when welding.
There are three main types of PPE used in welding. The first type of personal protective equipment is impact-resistant gloves, which help prevent burns and cuts caused by molten metal splashing or flying off the surface while welding.
The second type of gear is welding helmets that protect the welder’s head and face from debris falling on them. This gear also protects the welder’s face from direct sunlight as well as any sparks or pieces of metal that may fly off the workpiece.
The final piece of PPE used in welding is safety glasses, which are worn to protect the welder’s eyes from flying metal splashes.
The layer of Clothing a welder wears should be based on what type of metals they’re most likely to be working with.
What Are The Hazards Of Welding Stainless Steel?
The two main hazards of welding stainless steel are the heat and the fumes released. The molten metal is quite hot especially when welding mild steel or steel with a low melting point, so you need to take safety precautions to protect yourself.
Welding stainless steel also produces fumes so wearing a respirator is important.
Alloying elements are used to increase the strength and durability of stainless steel, but they can also contribute to its flammability. This is why welding in an area where there are any combustible materials is not recommended.
What Hazard Can Be Caused From Welding Near Combustible Material?
When welding near combustible material such as wood, paper or rubber the weld can heat up these materials and they might catch fire.
A potential problem with welding near combustible materials is that the welds may not be strong enough to support the nearby structure.
Another potential risk is that there might not be enough space for you to move around while you’re welding because there’s combustible material close by.
This can make it harder for you to get out of danger when something goes wrong, like if something catches fire.
What Are The Four Basic Welding Positions?
A number is used to define the position and an F for Fillet G is normally used in reference to the groove which means the type of the weld.
1. Flat Position (1G or 1F),
This is when the flat surfaces are parallel to each other. The face of the weld is nearly horizontal. The axis of a weld is located at the intersection of the longitudinal and transverse axes.
The axis is a line that runs through the length of the weld and is perpendicular to its cross section at its center.
2. Horizontal Position (2G or 2F),
In horizontal welding, the weld axis is approximately horizontal, but the type of joint dictates the complete definition. In this instance, for a butt weld, it is at right angles to the edges of both pieces being joined.
The angle of the weld can be characterized by measuring the distance between edges of the pieces to which it is being made.
3. Vertical Position (3G or 3F),
Most of the time, the axis of a vertical weld is approximately vertical. The term “vertical position welding” refers to a process where a work piece is fixed in place and then passed through an arc.
It is generally used when welding pipe to a vertical support surface.
4. Overhead Position (4G or 4F),
In overhead welding, the metal deposited tends to drop or sag on the plate, causing the bead to have a high crown. This is because the arc that forms is on top of a thick layer of liquid and gas.
The arc depends on the process and it is classified by the distance from the work piece to the plate.
What Are The Essentials Of Proper Welding?
Aside from the consistent sizzling sound produced by a proper arc, the form of the molten pool and the movement of the metal at the back of the pool serve as guides in determining weld quality.
A properly created deposit will have consistent ripples on the bead and will be smooth with no overlaps or undercuts.
Some of the basic essentials include;
1, Correct current.
You will be dissatisfied in your weld if the current on your equipment is too high or too low.
If the temperature is too high, the electrode melts too quickly, resulting in a huge and irregular molten pool; if the temperature is too low, there is insufficient heat to melt the base metal, resulting in a tiny, piled-up, irregular molten pool.
2. Exact arc length.
When the arc is prolonged or the current is too high, the metal melts off the electrode in massive globules that wobble from side to side as the arc wavers, resulting in a broad, spattered, and irregular bead with poor fusion between the initial and deposited metal.
3. Appropriate electrode size.
The type, position, and preparation of the joint, as well as the electrode’s capacity to carry high current values without harming the weld metal or reducing deposition efficiency, all contribute to the selection of electrode size and the required current values.
4. Appropriate travel speed.
When your momentum is too quick, your pool does not keep contaminants and gas out for long enough. The bead is pointy, rippled, and slender.
The metal builds up when the pace is too slow, and the bead becomes high and broad with a rather straight ripple.
5. Right electrode angle
In fillet welding and deep groove welding, the electrode angle is especially important.
When performing a fillet weld, hold the electrode such that it bisects the angle between the plates and is perpendicular to the line of weld, and if undercut occurs in the vertical member, reduce the angle of the arc and guide the arc toward the vertical member.
What Is ASME Code Welding?
ASME welding codes and standards are set with the purpose to ensure that every weld is made correctly and safely.
The ASME code mandates that welders possess certification for certain welding techniques used to construct ASME code vessels. The welders and the equipment are carefully tested to ensure that they meet the exacting standards.
Advantages of ASME welding codes include:
- The welders are properly trained and educated in the proper techniques for all welding.
2, Proper selection of filler metals and consumable metals.
3, Close attention to details like welding procedures, scrap, deformation of the plate or electrode during welding etc.
Welders must possess basic qualifications as well as additional training and experience to be certified in each code welding procedure. A welders certification may be revoked for fabrication of code welds that do not meet code requirements.
What Is The Difference Between WPS And PQR?
WPS stands for Welding Procedure Specification, this document is kept by the superintendents, who have responsibility for certain structures or parts of structures.
PQR stands for Process Qualification Record, this is a log of information about the type of materials used, welding procedure and other pertinent data that is used by the quality department to ensure that each and every ship meets specification.
The PQR records are kept in a safe place and are reviewed regularly to ensure the processes are being followed.
How Long Is A PQR Valid For?
A PQR is valid for three years, and it must be reviewed before the end of that time period. A PQR is absolutely no good if left lying on a shelf, you need to ensure that you are following a procedure by first declaring it as your PQR.
Change of parameters change the process, and each time you change something, you need to revise the PQR. Revisiting this document will allow you to decide if any changes are required.
Change of welding procedure can be due to a change in material, joint design type or a revision in existing procedures. Revising your PQR will allow you to track which parameters have changed and where they are different from those used in previous procedures.
How Do You Run PQR?
After completion of welding you take the item to lab and fill in the PQR. Then you sign it and date it, then send it off to the quality department by first putting all relevant information in a cover note and then ensuring that you include a copy of your welding certificate.
If you wish to change any parameters, perform an evaluation of that parameter with the supervisor to determine if there is a need for a change.
If you are performing welding on an assembly and you have made some changes, ensure that all pertinent data are included in the PQR when submitted for testing.
Do Welding Procedures Expire?
Welding procedure have expiry date based on the work that is being performed and indicated in the procedure qualification records.
Look at the welding procedure and ensure that you are using the right equipment, followed all operational procedures, and handle the material in accordance to your safety guidelines.
After a period of time any changes should be addressed and reported back to quality control department.
Your PQR will be reviewed by supervisor who will take decisions regarding samples that have been submitted and also when they require a change based on parameter changes, or if required welding procedures need to be changed.