Free Basics of Piping Questions and Answers — Questions and Answers
Question 1: In a plumbing system, a valve is used for:
- Flow control
- Flow isolation
- Pressure Regulation
- All of these (Correct answer)
Correct answer: All of these
Valves are essential components in any piping or plumbing system, serving multiple critical functions. They are used to control the flow rate of fluids, completely isolate sections of a system for maintenance or safety, and regulate pressure to ensure safe and efficient operation. Depending on their design, different types of valves are optimized for these specific purposes, making them indispensable for system management.
Question 2: Another name for a non-return valve is?
- Globe valve
- Gate valve
- Check valve (Correct answer)
- Control valve
Correct answer: Check valve
A non-return valve is commonly known as a check valve. Its primary function is to allow fluid to flow in only one direction and automatically prevent backflow, which can cause damage to pumps, contamination of the system, or other operational issues. This unidirectional flow control is crucial in many piping applications to maintain system integrity and efficiency.
Question 3: What grade of stainless steel is known as acid proof steel?
- SIS 2333
- AISI 316 (Correct answer)
- SIS 2359
- AISI 304
Correct answer: AISI 316
AISI 316 stainless steel is often referred to as 'acid-proof steel' due to its superior corrosion resistance, especially against chlorides and various acids, compared to AISI 304. This enhanced resistance comes from the addition of molybdenum to its composition. It is widely used in marine environments, chemical processing, and medical applications where high resistance to corrosive media is required.
Question 4: What does isometric indicates' cloud marking mean?
- Change in isometric
- Change in Piping system
- Change occurred in Revision (Correct answer)
- Change in material
Correct answer: Change occurred in Revision
In piping isometric drawings, a 'cloud' or 'revision cloud' drawn around a specific area indicates that a change has been made to that part of the drawing since the previous revision. This visual cue helps engineers and fabricators quickly identify modifications and ensure they are working with the most up-to-date design information. It's a standard practice for revision control and communication in engineering documentation.
Question 5: Which of the following does not correspond to a flange facing classification?
- Raise Face
- WNRF (Correct answer)
- Flat face
- Ring type joint
Correct answer: WNRF
Flange facing classifications describe the design of the sealing surface of a flange, such as Raised Face (RF), Flat Face (FF), and Ring Type Joint (RTJ). WNRF, however, stands for 'Weld Neck Raised Face,' which describes the *type* of flange (Weld Neck) combined with its facing (Raised Face), not solely a facing classification itself. It's a comprehensive description of a specific flange style, not just its sealing surface.
Question 6: Which material is most frequently used for gaskets?
- PVC
- Graphite
- Compressed Asbestos Fibre (Correct answer)
- Steel
Correct answer: Compressed Asbestos Fibre
Historically, Compressed Asbestos Fibre (CAF) gaskets were extremely common due to asbestos's excellent heat resistance, chemical inertness, and sealing properties. While health concerns have led to a significant reduction in its use and a shift towards non-asbestos alternatives in modern practice, CAF was for a long time the most frequently utilized material for gaskets in many industrial applications.
Question 7: Which kind of 90-degree elbow is most frequently utilized in plumbing
- 1D elbow
- 5D elbow
- 3D elbow (Correct answer)
- 1.5D elbow
Correct answer: 3D elbow
A 3D elbow refers to an elbow where the radius of curvature is three times the nominal pipe diameter (3D = 3 x NPS). While 1.5D (long radius) and 1D (short radius) elbows are also common, 3D elbows offer a smoother flow path with less pressure drop than shorter radius elbows, making them a good balance between space requirements and hydraulic performance in many plumbing and process applications. This balance makes them a frequent choice.
Free Basics of Piping Questions and Answers
In a plumbing system, a valve is used for: