Monday, 25 September 2017

Q:- A medium carbon steel weld shoukd be inspected:

1. As soon as it is safe to do so
2. When the weld is finished
3. 48hrs after the completion
4. After ndt examination

Sunday, 10 September 2017

Q:-Lineup clamps shall be used for butt welds in accordance with the procedure specification. When it is permissible to remove the lineup clamp before the root bead is completed:

1. The completed part of the bead shall be in approximately equal segments spaced approximately equally around the circumference of the joint. 
2. The completed part of the bead shall be removed and rewelded after removing the clamp. 
3. The completed part of the bead shall be peened before removing the clamp. 
4. The completed part of the bead shall be at least 4 inches long for all pipe sizes 
5. None of the Above

Wednesday, 6 September 2017

Top 10 Interview Questions Related To Pipes Supports

Interview Questions Related To pipes Supports:-

1. What are the Criteria for Pipe Supporting?

Answer: -

Following are the points, which should be taken into account for proper supporting: -

A. Load of bare pipe + fluid + insulation (if any).
B. Load of bare pipe + water fill.
C. Load of valves and online equipment and instrument.
D. Thermal loads during operation.
E. Steam out condition, if applicable.
F. Wind loads for piping at higher elevation, if required.
G. Forced vibration due to pulsating flow.
H. Bare pipe with size above 12” shall be supported with Pad or Shoe.

2. What is the basic span of supports for 2”/6”/10”/24” pipe?

Answer: -

Basic Span is 5.5m / 9m / 11.5m / 15m respectively.

3. What is the function of providing the anchor, cross guide and guide for piping?

Answer: -

Anchor is provided to restrict all the axial and rotational movements of pipe, whereas cross guide is
provided to restrict displacements of pipe along with the axis perpendicular to its centerline and Guide is provided to restrict the longitudinal movements of pipes along with its axis.

4. How is piping to Tank inlet nozzle is supported and why?

Answer: -

Piping to Tank Nozzle is supported with spring type support (first support from Nozzle) in order to
make the nozzle safe from the loads which occurs due to the displacement of pipe ( Displacement
may be due to thermal expansion of pipe, tank material, tank settlement etc).

5. What are the types of flexible spring hangers?

Answer: -

1. Constant Spring Hanger 2. Variable Spring Hanger.

6. What is the purpose of providing Graphite Pads in supports below shoes?

Answer: -

To reduce the friction factor. The coefficient of friction for Graphite Pads is 0.1

7. Where do you provide Anchor and Slotted Support of Heat Exchanger?

Answer: -

Anchor support of Heat exchanger is provided on the side from which Tube bundle will be pulled out for the purpose of maintenance work also it is based on the growth of the connecting piping as
exchanger should grow with the piping.

8. What should be the material of shoes for supporting AS pipes & why?

Answer: -

If CS shoes are used then pad in contact with the pipe shall be of Alloy steel to avoid dissimilar
welding at pipe. To avoid alloy steel welding and dissimilar welding, fabricated clamps either of CS or SS can be used.

9. What are sway braces?

Answer: -

Sway braces are essentially a double acting spring housed in a canister. Their purpose is to limit the
undesirable movement. Undesirable movement means movement caused by wind loading, rapid
valve closure, relief valve opening, two phase flow or earthquake.

10. What is the difference between variable spring hanger and constant spring hanger?

Answer: -

Variable spring Hanger: -
As the name itself indicates the resistance of the coil to a load changes during compression.
Constant spring Hanger: -
Constant spring hanger provides constant support force for pipes and equipment subjected to vertical movement due to thermal expansion.

Monday, 4 September 2017

Q:- What is meant by the term junction?

1. The area containing the HAZ and the weld metaL
2. The weld metal and parent metal
3. The boundery between the fusion zone and the HAZ
4. The part of the weld, has undergone mettalurgical changes due to the heat from welding