This unit forms part of the Course in MCAST Award in Weldability of Metals and the Management of Engineering Welding. Once a learner complete all the units in this course satisfactorily; that is has obtained a pass mark in the assessment and respected the 80% attendance s/he will achieve an award pegged at MQF Level 5, 20 ECVET Credits
This unit covers the versatility of fixtures and positioners to facilitate welding projects and ensure good quality welds by reducing human errors. The use of fixtures and positioners to increase production and decrease the cost of welding projects, handling and the safety requirements that one needs to consider when designing and using such dedicated equipment are also an integral part of the course.
Known hazards for most common welding, cutting and other related processes and the practices that one must adopt to minimize personal injury and property damage, form the core part of this unit. However, learners should always read and understand the manufacturer’s instructions on safe practices for the materials and equipment being used in every particular situation and do not rely only on the content covered by this unit.
This is a 32 hrs of guided learning course. Students need to invest further hours in the course, which will include private study and home assignments.
Lessons are held as indicated on the prospectus and website.
Learning Outcome 1: Evaluate the appropriate use of welding fixtures and positioners
- Fixture: holding of parts during assembly by – bars, clamps, spacers etc
- Design features: convenient and accessible welding position, strong and rigid, ease of handling, level of accuracy, tack welding and welding design, quick moving components, friendly to operator,
- Design parameters: type of fixturing, tolerance and distortion requirements of the assembly, Jointing process, accessibility to the joint, limitations of fixture materials, Service life, number of fixtures needed to meet production, root face control provision: ceramic blocks, bed of flux, copper bars, arc blow control
- Design features: manual or automatic movement to optimize joint position for: welding position, cleaning, inspection, machining, weld repair.
- Considerations: Deposition rates, welder skill, operator factor and set-up costs, weld quality
- Types of positioning: one motion, two motion, three motion: Turning rolls, Headstock – Tailstock Positioners, Turntable Positioners, Tilting-Rotatinf Positioners, Drop-centre Tilting Positioners, Powered Elevation Positioners
- Technical Considerations: Centre of Gravity: parameters – torque from load, weight, tractive effort
Learning Outcome 2: Describe general housekeeping and protection from hazards at the work place and surrounding areas
- General welding safety: Management support, Training; General: Protection screens, Wall reflectivity; Public demonstrations: Fire, Explosion, Burns, Noise, Hot Work permit systems, Machinery guards
Learning Outcome 3: Summarise the main Hazards from Welding Fumes, Gases and Electrical Sources
- Arc Welding nature and sources: Welding fumes as a byproduct of vaporization, oxidation, and condensation from consumables and parent metal
- Potential hazardous gases: carbon monoxide, oxides of nitrogen, ozone, and phosgene or other decomposition products of chlorinated hydrocarbons
- Oxyfuel Gas Welding and Cutting
- Exposure factors: Position of the head, type of ventilation, shop size, number of welders, design of welding helmet, base metal and surface condition
- Electrical Sources:
- Electrical Shock: Shock mechanism, shock sources; Equipment selection; Installation; Grounding; Cables and Connections; Multiple arc welding operations, Modification and Maintenance, Prevention of fires
Learning Outcome 4: Recommend adequate ventilation requirements
- Ventilation methods: Natural, General area mechanical ventilation, Overhead exhaust hoods, portable local exhaust devices, downdraft tables, cross draft tables, local ventilation, Respiratory Protective Equipment
- Special ventilation situations: Welding in confined spaces, welding of containers, Highly toxic materials, Fluorine Compounds, zinc, Cleaning compounds, chlorinated hydrocarbons, cutting of stainless steel
Learning Outcome 5: Choose the appropriate method to handle compressed gasses
- Gas Cylinders and Containers: Filling, Usage and storage, Withdrawal of Gas, Pressure Relief Devices
- Cryogenic Cylinders and Tanks; Regulators; Manifolds; Fuel Gases; Fuel Gas Fires; Shielding Gases
- Oxyfuel Gas Welding and Cutting: Torches, Hoses, Backfire and Flashback, Hose Line Safety Devices, Shutdown Procedures
The following are the suggested pre-requisites and/or entry requirements needed:
- Hand on experience in one or more welding process.
- Knowledge of local Health and Safety Legislation
- Familiar with construction/ industrial sites.
- Level 4 or above in Welding and Fabrication.
- Level 4 in Physics plus industry experience.
Applicants may be called for an interview prior the commencement of the course.
Course participants may be awarded either an MCAST Certificate of Attendance or an MCAST Certificate of Achievement.
MCAST Certificate of Attendance
- An MCAST Certificate of Attendance will be awarded to those candidates who attend at least 80% of the lessons.
MCAST Certificate of Achievement
- An MCAST Certificate of Achievement will be awarded to those candidates who satisfy the 80% attendance criteria AND ALSO choose to sit and pass the course assessment/s.
- Students who opt not to sit for the assessment/s or fail (the assessment/s) will however be awarded an MCAST Certificate of Attendance provided that they fulfill the minimum attendance criteria as stated above.
If the student intends to obtain a Certificate of Achievement, she/he is required to sit for an assessment/s. Assessment/s may take various forms such as a home assignment, class assignment, practical test and time constrained test. However, the assessment/s is not compulsory and an applicant may choose not to sit for it.
There are no additional costs or special materials / equipment to bring.