16 Important Question related to Piping Equipment and Piping Layout

1. What are the steps involve in Plant design?
Answer: -

The mechanical design and development of the plant has three major steps as: -
A. Conceptual layout design.
B. Equipment layout design.
C. Piping layout design.

2. What is conceptual layout design?
Answer: -

It is the part of basic engineering package. It consists of following information: -
A. Essential process design requirement such as horizontal & vertical relationship of equipment.
B. Space allocation for basic plant requirement (space required for laboratories, office, storage etc.)
C. Planning for control room, motor control center room etc.

3. What is Equipment layout design?
Answer: -

It is the detailing of conceptual layout. It is the basic document of mechanical engineering design or in
other words this document is the basis for development of construction drawing by all disciplines. It is
sometimes also referred as plot plan for large outdoor plant.
It consists of following information: -
A. Floor space needed for the equipment and other facilities are shown.
B. Access, removal space, cleaning area, storage space and handling facilities are outlined.

4. What are the essential data/ documents required for preparation of equipment layout?
Answer: -

The essential data or documents required for preparation of equipment layout is as: -
A. Process flow diagrams (PFD) and Piping & instrument Diagrams (P& ID).
PFD/ P& ID indicates the inter connectivity of each equipment, information regarding solid
handling, gravity feed, line slopes, loop sizes, venting requirement, special piping materials etc.
which in turns governs the equipment location to a great extent.
B. Project design data.
This consists of following information as: -
* Geographic location, proximity to roads and railway, topography and local codes and regulations,
weather conditions such as rainfall records, seasonal temperature differences, wind direction,
outlet points for drains etc.
*The above information such as wind direction influences the location of cooling towers, furnaces,
stacks etc. Similarly, the information regarding outlet drain points affects the design of storm water
drains and requirements of enclosures.
C. Equipment sizes and Building.
This includes fabricated equipment such as vessels, Heat Ex-changers, Reactors, Tanks and
proprietary equipment like pumps, Compressors, Furnaces etc. For locating the above, the
equipment is grouped to have optimum location for minimum pipe run as well as fallow the process
flow sequence.

5. What are the two basic configurations for the equipment layout (unit plot plan)?
Answer: -

The equipment layout can basically be divided into two configurations:
A. The Grade Mounted Horizontal arrangement as seen in the refineries and petrochemical plants.
B. The vertical Arrangement as seen in many chemical process industries.

6. What is Grade mounted Horizontal Arrangement of equipment layout?
Answer: -

In the Grade mounted Horizontal Arrangement, the equipment is placed on the either side of the
central pipe rack with auxiliary roads. Advantage of this arrangement is that the equipment is located
at grade level, which makes it easier to construct, operate and maintain. Disadvantage is that it takes
lot of ground area.

7. What is Vertical arrangement of equipment layout?
The structure mounted vertical arrangement has equipment located at multilevel in steel or concrete
structure. This could be indoor or outdoor. Advantage is of small coverage area and ability to house
the facility to suit process requirement or climate conditions.

8. What are the basic principles of locating the Equipment irrespect of the type of arrangement?
Answer: -

The certain basic principles to be followed while locating the equipment is as: -
A. Economic piping :
In order to minimize the cost of piping, the equipment should be located in process sequence and
close enough to suit safety needs, access requirements and flexibility. The equipments are identified
which forms the subsystem within the unit. The component within the subsystem to be arranged to
have most economical piping and the whole subsystem to be arranged within the unit to have most
economic interconnection.
B. Process Requirement:
The equipment layout should support requirement like minimum pressure drop, gravity feed and loop.
C. Common operation:
The equipment that requires common maintenance facilities, common utility and continuos operator
attention shall be located the same area.
D. Underground Facilities:
Before deciding the equipment location, the facilities such as storm water drain, effluent drain, fire
water, cooling water to be placed underground.

9. What is Line Routing Diagram?
Answer: -

A line routing diagram is a schematic representation of all process and utility-piping system drawn on
a copy of plot plan. This diagram does not show the exact locations, elevations or interference but it
locates the most congested area.

10. How do you calculate the width of Pipe rack?
W = (f X n X s) + A + B.
…Where, f : Safety Factor
= 1.5 if pipes are counted from PFD.
= 1.2 if pipes are counted from P&ID.
n : number of lines in the densest area up to size 450NB.
= 300 mm (Estimated average spacing)
= 225 mm (if lines are smaller than 250 NB)
A : Additional Width for:
: Lines larger than 450 NB.
: For instrument cable tray / duct.
: For Electrical cable tray.
S : 300 mm (estimated average spacing)
: 225 mm (if lines are smaller than 250 NB)
B : future provision
= 20% of (f X n X s) + A

11. Up to what limit the width of pipe Rack is restricted? What type of arrangement shall be done
if the width of rack calculated is more then the restricted limited?
Answer: -

Normally pipe Rack width is limited to 6.00 Mtrs. If the width of rack calculated is more then the
arrangement shall be done in multiple layers. The arrangements adopted are: -
A. Single column Rack ‘T’ type.
B. Double column Rack with a single tier.
C. Double column Rack with a double tier.

12. How much space is kept in between column of pipe rack?
Answer: -

Normally, 5 to 6 Mtrs. spacing is kept in between the column of pipe rack.

13. At which location the wide spacing (spacing more than the normal) in between the column is
Wide spacing is necessary at road crossing or where loading or access space is needed.
14. How much Headroom clearance is required under the following type of crossing?
A. Structures/ pipe lines inside operating area.
B. From top of the Rail.
C. Above crest of road for crane movement.
D. Above crest of road for Truck movement.
E. Above crest of road between process units.
Answer: -

The Headroom normally provided is as: -
A. Structures/ pipe lines inside operating area. : 2200
B. From top of the Rail. : 7000
C. Above crest of road for crane movement. : 7000
D. Above crest of road for Truck movement. : 6000
E. Above crest of road between process units. : 4500
15. What sort of drawing/ layout is required for piping layout?
Answer: -

The following Drawing/ Layout are required for piping layout.
A. Piping & instrumentation Diagram (P& ID).
B. Equipment Layout.
C. Piping Specification.
D. Equipment Drawing.
E. Vendor Requirement for proprietary equipment.

16. What care shall be taken while routing piping for instruments?
Answer: -

Following points shall be taken care of while routing piping for instruments.
A. Flow measuring instrument needs certain straight length on upstream & downstream of the
instruments. Normally, 15D on the upstream and 5D on the downstream is kept.
B. The pipe line in which flow meters such as magnetic flow meters, vortex meters, turbinemeters etc
are located shall be routed in such a way that the line must be filled with liquid all the time. The
pipe line shall be supported with robust support on both side of the meter.
C. Control valves are located at grade e.g. at about 500mm height from finished ground to provide
convenient access for operation and maintenance. Block and bypass valve shall be located to
have easy operation/ access from the grade. Locating control valve on the vertical line shall be
D. Isolation valves for level gauges and pressure gauges shall be made accessible. All primary and
secondary indicators of pressure, temperature, flow, level, positioners etc shall be visible from the
operating area.
E. Rotameter shall be placed on vertical line and the inlet shall be from the bottom of the instrument.

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