10+ Pipe Fabricator Interview Questions and Answers

Dimensions of the elbow of unknown degree are calculated using trigonometry and geometry.

• Calculate the centerline radius of the elbow.

• Use trigonometry to find the length of the elbow.

• Consider the angle of the elbow to determine the dimensions.

• Measure the outside diameter and wall thickness of the pipe for accurate calculations.

Metals such as stainless steel, carbon steel, and aluminum are commonly used before the welding process.

• Stainless steel is often used for its corrosion resistance and durability.

• Carbon steel is commonly used for its strength and affordability.

• Aluminum is lightweight and has good conductivity, making it suitable for certain applications.

Proper gap in pipe jointing is crucial for effective TIG and ARC welding, ensuring strong and defect-free welds.

• For TIG welding, a gap of 1/16 inch (1.6 mm) is generally recommended for thin-walled pipes.

• For thicker pipes, a gap of 1/8 inch (3.2 mm) may be necessary to allow for proper penetration.

• In ARC welding, a gap of 1/16 to 1/8 inch is also common, depending on the pipe diameter and thickness.

• Example: For a 2-inch diameter pipe, a 1/16 inch gap ensures adequate fusion w...read more

Isometric drawings provide essential details for pipe fabrication, including dimensions, angles, and material specifications.

• Dimensions: Isometric drawings show the exact lengths and diameters of pipes, ensuring accurate cuts and fittings.

• Angles: They indicate the angles at which pipes must be installed, crucial for proper alignment and flow.

• Material Specifications: Drawings specify the type of materials to be used, such as steel or PVC, which affects durability and compatibi...read more

The pipe is injected with argon gas before welding to create an inert atmosphere.

• Before welding, the pipe is purged with argon gas to remove any oxygen and moisture that could contaminate the weld.

• This is typically done using a purge gas system that fills the pipe with argon and then vents it out before welding.

• Purging with argon helps prevent oxidation and ensures a clean, strong weld.

• Proper purging techniques are essential for high-quality welds in stainless steel and other...read more

Pipes can have various types of seams, primarily categorized into welded and seamless types.

• Welded pipes have seams created by welding two pipe ends together.

• Seamless pipes are manufactured without seams, providing higher strength.

• Common types of welded seams include longitudinal and spiral seams.

• Examples of welded pipes include ERW (Electric Resistance Welded) and SAW (Submerged Arc Welded) pipes.

Gaskets are sealing devices used to prevent leakage between two surfaces, available in various materials and designs.

• 1. Rubber Gaskets: Commonly used in plumbing and automotive applications for their flexibility and resistance to water.

• 2. Metal Gaskets: Used in high-pressure applications, such as in engines, due to their durability and heat resistance.

• 3. Cork Gaskets: Often used in oil pans and valve covers, providing good sealing properties and compressibility.

• 4. Spiral Woun...read more

To fit up a valve, follow these steps: measure and mark the pipe, cut the pipe, deburr the edges, clean the pipe and valve, apply pipe dope or Teflon tape to the threads, align the valve with the pipe, tighten the valve onto the pipe using a wrench.

• Measure and mark the pipe where the valve will be installed

• Cut the pipe using a pipe cutter or saw

• Deburr the edges of the pipe to remove any sharp or rough edges

• Clean the pipe and valve to remove any dirt or debris

• Apply pipe dope o...read more

There are several types of flanges used in pipe fabrication.

• Weld Neck Flange

• Slip-On Flange

• Socket Weld Flange

• Threaded Flange

• Blind Flange

• Lap Joint Flange

Pipe schedule refers to the thickness of a pipe wall and is used to determine the pressure capacity and strength of the pipe.

• Pipe schedule is a standardized system used to classify the thickness of pipes.

• It is denoted by a number followed by the letter 'S', such as Schedule 40 or Schedule 80.

• The higher the schedule number, the thicker the pipe wall and the higher the pressure capacity.

• Pipe schedule is important in industries like oil and gas, chemical, and construction.

• For ex...read more

The center of a 24-inch pipe elbow is the point where the centerline of the pipe intersects with the centerline of the elbow.

• The center of the elbow is where the centerline of the pipe intersects with the centerline of the elbow

• The center of the elbow is important for proper installation and alignment

• The center of the elbow can be calculated using mathematical formulas or measured using specialized tools

Pipe fabrication is the process of creating piping systems by cutting, bending, and assembling pipes to meet specific project requirements.

• Involves cutting, bending, and welding pipes to create a piping system

• Requires knowledge of different types of pipes and fittings

• Common materials used include steel, copper, and PVC

• Used in various industries such as construction, oil and gas, and manufacturing