EBK 3I-EBK: WELDING PRINCIPLES & APPLIC
8th Edition
ISBN: 9780176919764
Author: Jeffus
Publisher: VST
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Chapter 7, Problem 22R
What should be done if the torch flashes back?
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20-4-2025
Exam-2-Tribology
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7. Viscosity of multi-grade oils
(a) Reduces with temperature
(c) is less sensitive to temperature
(b) Increases with temperature
(d) None of the above
8. In a hydrodynamic journal bearing if eccentricity ratio = 1, it means
(a) Journal/shaft is subjected to no load and the rotational speed is very high.
(b) Journal is subjected to no load and the rotational speed is moderate
(c) Journal is subjected to very light load and the rotational speed is very high.
(d) Journal is subjected to very high load and the rotational speed is negligible.
Q4/ The journal speed of a 100mm diameter journal is 2500 rpm. The journal is supported by
a short hydrodynamic bearing of length L=0.6D, eccentricity ratio = 0.75 and a clearance
ratio C/R=0.001. The radial load on the bearing is 10 kN. The lubricant is SAE 30, and the
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Q1/A/ Compare between the long and short journal bearings
B/ With the help of Stribeck's curve, discuss different regimes of lubrication.
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B/What are the differences between grease and Synthetic oils
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B/What are the criteria to classify sliding bearings?
C/ Answer of the following:
1. According to the SAE viscosity classification, the oil (SAE 40) is lower viscosity than the
oil (SAE 20) at the same temperature. (True or False)
2. For a slow speed-highly loaded bearing, used oils of high viscosity; while for high-speed…
Chapter 7 Solutions
EBK 3I-EBK: WELDING PRINCIPLES & APPLIC
Ch. 7 - Using Table 7-1, list the six different fuel gases...Ch. 7 - What metals can be cut with the oxyfuel gas...Ch. 7 - What other term is used to refer to the OFC...Ch. 7 - What is a combination welding and cutting torch?Ch. 7 - State one advantage of owning a combination...Ch. 7 - State one advantage of owning a dedicated cutting...Ch. 7 - What is a mixing chamber? Where is it located?Ch. 7 - Define the term equal-pressure torch. How does it...Ch. 7 - How does an injector-type mixing chamber work?Ch. 7 - State the advantages of having two oxygen...
Ch. 7 - Why are some copper alloy cutting tips...Ch. 7 - Using Table 7-4, answer the following: a . Oxygen...Ch. 7 - What determines the amount of preheat flame...Ch. 7 - What can happen if acetylene is used on a tip...Ch. 7 - Why are some propane and natural gas tips made...Ch. 7 - What types of tip seals are used with cutting...Ch. 7 - If a cutting tip sticks in the cutting head, how...Ch. 7 - How can cutting torch tip seals be repaired?Ch. 7 - What is used to reduce the high cylinder or system...Ch. 7 - What do the two pressure gauges on a regulator...Ch. 7 - Why must the gas pressure be released and the...Ch. 7 - What should be done if the torch flashes back?Ch. 7 - What is the purpose of a reverse flow valve?Ch. 7 - Why must the reverse flow valve and the flashback...Ch. 7 - How can a hose be checked for leaks?Ch. 7 - Why is the oxygen valve turned on before starting...Ch. 7 - Why does the preheat flame become slightly...Ch. 7 - What causes the tiny ripples in a hand cut?Ch. 7 - Why is a slight forward torch angle helpful for...Ch. 7 - Why should cans, drums, tanks, or other sealed...Ch. 7 - Why is the torch tip raised as the cutting lever...Ch. 7 - Why are the preheat holes not aligned in the kerf...Ch. 7 - Sketch the proper end shape of a soapstone that is...Ch. 7 - What are two methods you can use to determine what...Ch. 7 - What is the best way to set the oxygen pressure...Ch. 7 - Why is it important to have extra ventilation...Ch. 7 - What factors regarding a cut can be read from the...Ch. 7 - What is hard slag?Ch. 7 - Why is it important to make good-quality cuts?Ch. 7 - When using an ordinary welding table, what can be...Ch. 7 - Describe the methods of controlling distortion...Ch. 7 - List three things that can become a problem when...Ch. 7 - How does cutting small-diameter pipe differ from...
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