Minimum Size of Fillet Weld

Every inspector has dealt with the design rules that prohibit sizing a fillet weld below a certain size for a given thickness of material? If you look at AWS D1.1 2020 Structural Welding Code (Steel) you can find this in Table 7.7. If you happen to own a copy of AISC 360-16 Specification for Structural Steel Buildings you’ll find this on Table J2.4. Below you can see AISC’s Table J2.4 – Minimum Size of Fillet Welds.  The minimum fillet weld sizes are basically based on the thickness of the material being joined. Most people think that the minimum fillet weld sizes are … Continue reading Minimum Size of Fillet Weld

Heat input and Weld size (leg-length)

Heat input from welding is important because it has an effect on cooling rates which in turn can significantly affect the mechanical properties of the weld and heat-affected zone. It also plays a role in susceptibility to distortion. High heat input can be beneficial in some cases and detrimental in others. A common misconception is that as long as amperage and voltage remain the same heat input doesn’t change. This is wrong because travel speed is also a factor. Heat input is a function of three essential variables: amperage, voltage, and travel speed. Change one and heat input changes. The formula for … Continue reading Heat input and Weld size (leg-length)

How to control distortion in welding?

Distortion caused by the heating and cooling cycles of welding is extremely problematic. It can place structures out of dimensional tolerance creating costly rework. In some cases, parts need to be scrapped. Understanding the causes of distortion is an absolute necessity for those managing welding operations. Three mistakes account for the vast majority of distortion problems. These are: Over-welding One of the things you may hear most often when it comes to reducing or eliminating distortion from welding is to pulse weld. Pulse welding is done by switching back and forth between a peak (high) and a background (low) current. Manufacturers of welding … Continue reading How to control distortion in welding?

What is quenching?

『𝐐𝐮𝐞𝐧𝐜𝐡𝐢𝐧𝐠 𝐚𝐬 𝐚 𝐇𝐞𝐚𝐭 𝐓𝐫𝐞𝐚𝐭𝐦𝐞𝐧𝐭』 ↳𝗤𝘂𝗲𝗻𝗰𝗵𝗶𝗻𝗴 is a vital heat treatment process used to rapidly cool a material, typically a metal alloy, from a high temperature to room temperature or below. ↳𝗠𝗲𝗰𝗵𝗮𝗻𝗶𝘀𝗺 𝗼𝗳 𝗤𝘂𝗲𝗻𝗰𝗵𝗶𝗻𝗴:1- 𝙃𝙚𝙖𝙩𝙞𝙣𝙜:The material is heated to a specific temperature, typically above its critical transformation temperature.2-𝙍𝙖𝙥𝙞𝙙 𝘾𝙤𝙤𝙡𝙞𝙣𝙜 & 𝙋𝙝𝙖𝙨𝙚 𝙏𝙧𝙖𝙣𝙨𝙛𝙤𝙧𝙢𝙖𝙩𝙞𝙤𝙣:Upon rapid cooling during quenching, the material undergoes a phase transformation depending on the composition of the material.The most common phase transformation associated with quenching is the formation of 𝙢𝙖𝙧𝙩𝙚𝙣𝙨𝙞𝙩𝙚, a hard and brittle phase characterized by a unique crystal structure (BCT). ↳𝗤𝘂𝗲𝗻𝗰𝗵𝗶𝗻𝗴 𝗠𝗲𝗱𝗶𝘂𝗺𝘀:Different quenching mediums have varying cooling … Continue reading What is quenching?

𝐁𝐨𝐥𝐭 𝐆𝐫𝐚𝐝𝐞𝐬 (8.8) 𝐯𝐬. (10.9)

𝐁𝐨𝐥𝐭 𝐆𝐫𝐚𝐝𝐞𝐬 (8.8) 𝐯𝐬. (10.9) 1️⃣ 𝗕𝗼𝗹𝘁 𝗚𝗿𝗮𝗱𝗲 (8.8)Grade 8.8 bolts are made of medium carbon alloy steel.They have a minimum tensile strength of 800 MPa and a minimum yield strength of 640 MPa.These bolts are known for their moderate strength and durability.They are commonly used in machinery, automotive parts, and general engineering applications. 2️⃣ 𝗕𝗼𝗹𝘁 𝗚𝗿𝗮𝗱𝗲 (10.9)Grade 10.9 bolts are made of alloy steel and have a higher strength than Grade 8.8 bolts.They have a minimum tensile strength of 1000 MPa and a minimum yield strength of 900 MPa.These bolts are specifically designed for applications that require high strength … Continue reading 𝐁𝐨𝐥𝐭 𝐆𝐫𝐚𝐝𝐞𝐬 (8.8) 𝐯𝐬. (10.9)

Weld-neck vs Slip-on Flange

𝐊𝐞𝐲 𝐃𝐢𝐟𝐟𝐞𝐫𝐞𝐧𝐜𝐞𝐬 𝐁𝐞𝐭𝐰𝐞𝐞𝐧 𝐖𝐞𝐥𝐝 𝐍𝐞𝐜𝐤 𝐅𝐥𝐚𝐧𝐠𝐞𝐬 𝐚𝐧𝐝 𝐒𝐥𝐢𝐩-𝐎𝐧 𝐅𝐥𝐚𝐧𝐠𝐞𝐬 𝐢𝐧 𝐏𝐢𝐩𝐢𝐧𝐠 𝐒𝐲𝐬𝐭𝐞𝐦𝐬! 𝗪𝗲𝗹𝗱 𝗡𝗲𝗰𝗸 𝗙𝗹𝗮𝗻𝗴𝗲𝘀:✧ Designed with a long-tapered neck.✧ Butt-welded to the pipe, ensuring a smooth, continuous joint.✧ Offers exceptional strength and rigidity, distributing stress evenly and reducing the risk of leakage.✧ Ideal for high-pressure and high-temperature applications, such as in petrochemical, oil and gas, and power generation industries. 𝗦𝗹𝗶𝗽-𝗢𝗻 𝗙𝗹𝗮𝗻𝗴𝗲𝘀:✧ Feature a flat, circular shape with a slightly larger diameter than the pipe, making them easy to slip over the pipe.✧ Welded on the backside, primarily on the outer rim of the flange, simplifying alignment and installation.✧ Suitable … Continue reading Weld-neck vs Slip-on Flange

Pitting corrosions

𝗪𝗵𝗮𝘁 𝗶𝘀 𝗽𝗶𝘁𝘁𝗶𝗻𝗴 𝗰𝗼𝗿𝗿𝗼𝘀𝗶𝗼𝗻?✧ Pitting corrosion can be a major problem for metals, causing small pits or holes that weaken their structure.✧ Pitting corrosion is more aggressive than uniform corrosion as it concentrates corrosive elements at specific sites. 𝗛𝗼𝘄 𝗶𝘁 𝗼𝗰𝗰𝘂𝗿𝘀?✧ Pitting corrosion happens when a metal’s protective layer breaks down, allowing harmful substances to attack the surface and create small pits.✧ This occurs due to imperfections on the metal surface, contamination, or physical damage.✧ The affected areas dissolve, while the rest of the metal remains relatively unaffected. 𝗛𝗼𝘄 𝘁𝗼 𝗺𝗲𝗮𝘀𝘂𝗿𝗲 𝗶𝘁?We can use these techniques:1️⃣ Visual Inspection: Simply looking … Continue reading Pitting corrosions

Piping arrangement, gap, space, and layouts

𝐏𝐢𝐩𝐞 𝐀𝐫𝐫𝐚𝐧𝐠𝐞𝐦𝐞𝐧𝐭 𝐨𝐧 𝐏𝐢𝐩𝐞 𝐑𝐚𝐜𝐤𝐬 𝐁𝐚𝐬𝐞𝐝 𝐨𝐧 𝐀𝐒𝐌𝐄 𝐁31.3 ; The 𝘈𝘚𝘔𝘌 𝘉31.3 standard, which is used for industrial piping design in the oil, gas, petrochemical, and related industries, includes various provisions for the layout of pipes side by side. Some of the aspects addressed in this standard for pipe layout include: 𝐒𝐩𝐚𝐜𝐢𝐧𝐠 𝐛𝐞𝐭𝐰𝐞𝐞𝐧 𝐩𝐢𝐩𝐞𝐬: The 𝘈𝘚𝘔𝘌 𝘉31.3 standard specifies the minimum and maximum allowable spacing between pipes. This includes the spacing between parallel pipes and intersecting pipes. The objective is to ensure there is enough space for access, maintenance, and repair of the pipes. The purpose of specifying pipe … Continue reading Piping arrangement, gap, space, and layouts

What is Hydrates?

Hydrates are crystallized, compact, porous and rather light mass, similar to compressed snow. They are made of water, hydrocarbons, H2S and CO2. Unlike ice, hydrates have an unusual characteristic: they form at a temperature that is above water freezing point . For instance, they can form at 20 °C at particular pressures. When they are exposed to air, they dissolve chugging and fizzing because of the gas that is more or less slowly freed according to the surrounding temperature. When they are lit in the air, they can slowly and completely burn, until they leave a small residue of water. … Continue reading What is Hydrates?