Guidelines for Plot Plan / Layout Engineering

Introduction:

For preparation of PLOI PLAN of any plant, the concerned engineer has to proceed in a logical and sequential manner, before actually putting the unit-blocks on the drawing sheet. This note gives a guideline for the steps involved in preparation of a plot plan.

STEP 2

From step 1, we know that the total area which will be occupied by the present and future facilities is ‘A’ sq.m. To this we have to add the area required for General Facilities like Roads, Drains, Underground Services (Cable Trenches, effi. Drains, Storm water Pipes, Chambers, Manholes, Parking Places etc.) Approx. additional area required for these facilities can be calculated as given below, as first approximation.

Thumb-Rule : For Total Space requirement to accommodate all facilities, double the area calculated in the Table in Step No.1 i.e. (2A) sq.m. This has following basis as calculated below.

STEP 3

Having known that the iota] Plot Size required to accommodate all the facilities including process plant, off sites, utilities, non-plant buildings general facilities, is ‘2A’ sq.m, we can now approximately calculate,
the project-plot size.

At times, plot to be chosen for plant-facilities could be L-Shaped. However, actual Trial size and shape’ will depend on the over Land Size, shape and dimensions.

The plant has to be “fitted” in one of the above sizes (or L-Shaped if required).

STEP 4

Next step is to select the portion of the entire land belonging to the owner, which will be
developed to accommodate the Proposed Plant Facilities. For this purpose, we have to first demarcate the ‘Green Belt’ Zone. Minimum width of Green belt differs in different states and countries. Assume following sizes of ‘Total Land and Green Belts as applicable to the land in the example of step 3.

For selecting the most optimum portion of the Total Land, following check- list of governing Factors may be used.

a) Preferably rectangular (or square) shape should be chosen near one of the corners of the Land.

b) It should be nearest to the following public facilities

- Approach Road (State or Distr. Highway)

- Water-supply line (or other water-sources, Well etc.)

- Power-supply ‘Transmission Line (or the location where it can enter the land from the nearest source.)

- Disposal channel for storm-water disposal

c) Proximity to ideal locations for main switchyard/substation, Effluent Treatment Plant, Raw and Fire Water Storage-Tanks

d) Wind-direction.

e) Existing Tree-Plantation.

f) Suitability for Future expansion of the same-plant or other projects in the land.

g) Land Configuration - If the best location selected based on (a) to (f) above, happens to be a very low lying area needing 4 to 6 M filling, to bring it to the safe level above High Flood level, then we may have to select another area adjacent to it, which involves minimum cost of filling work.

h) Suitability of Access Road location from Main adjacent state-Road.

STEP 5

Having thus, located the portion of the land, based on the factors in Step 4, we can now blow-up the area ‘C’D’PQ’ (277 x 217 M) to suitable scale, generally 1:331/3, or 1:50 or 1:100 for a very Big-plot on AO or Al size sheet as given below.

- Draw grid-lines on 100 M x 100 M spacing as shown in STEP 4.

- Draw grid- lines on 50 Mx 50M spacing as shown in STEP 5

- Draw Name-plate, key-plan, N- lines (True 4 plant), ‘Table for List of Unit No, Unit -Name and plot-size.

- On key—plan Hatch the portion of whole land, selected for plot-plan as in STEP 4.

- SHOW ALL OTHER FEATURES AS INDICATED ABOVE.

STEP 6:

For locating different units (Blocks)onto the scaled-drawing as in STEP-S the best way to use A’-CAD Facility. If not available, use cut-pieces of CARD—BOARD cut to required size and shape drawn to the same scale as the plot drawn on Drawing as in STEP 5. Also cut the strips for Roads between adjacent plots. Approximately width of the strips will be

Road - 6M + Shoulders (2x2) = 4M, Drain (lx2) = 2M + Addl. Space (4M x 2)= 8M upto batt. limits -
………..Total = 20 M.

- Arrange the pieces within the specified plot (277 x 217 11 in the example-Step 5), giving consideration to following points.

a) Approximately main road spacing 100 M c/c. N-S and E-W (+ 10 to 20 M)

b) Locate Main-Process-Plant at appropriate place, away from front Boundary- line of the plot.

c) Impose the constraints on the layout and locate the respective units accordingly.

- Vastu Constraints (e.g. Water body near N-E-corner, Fire body near S-E corner etc.) as
specified by clients.

- Access Roads from main Roads

-. Gate House, Weigh- Bridge, Admin/Canteen block.

- Flare-stack as per wind-direction

- Close-ness of certain units like (main substation-incoming line) (Water -Tank - Incoming
Water Lire); (Process-Plant-Control Building- MCC-room etc.)

- Keep adjusting the Blocks and road strips until all blocks are arranged, satisfying all conditions of space requirements, space-constraints, mutual relationship etc.

- Finalize the locations and draw the plot boundaries, roads, drains (double lines) etc.

Number of Units in each plot with reference to the Table on the Drawing.

Number the roads, preferably as given below

All N-S Roads by odd Nos. 1,3,5,7,---- etc. with Rd.No.1, closest to the boundary. All E-W Roads by even Nos. 2,4,6,--- etc. with Rd.—2, closest, to south boundary which forms part of project boundary also. Sub -roads or in-plant Roads to be suffixed by A,B,C etc. e.g. roads - 4 and 6 to be numbered as Rd. 4A, Rd. 4B —-- etc. Roads beev~ and 5 to be numbered as 3A, 3B etc.

Note - WHILE PREPARING PLOT-PLAN, GIVE DUE CONSIDERATIONTO IHE FOLLOWING,
TO AVOID INTERFERENCE OF UNIT-AREAS.

1. ROAD TURNING RADIUS (See Table Above)

2. STORM-WATER, EL & IC-CABLES AND U/g PIPE-CROSSINGS NEAR THE JUNCTION AREA.

3. Statutory & Safety requirements, Safe distance etc.

Criteria for facility location

Utilities Boiler house :

- close to process plant. roads(6m min)at least from two sides.

- minimum pipe run to avoid excessive steam condensation high temperature lines.

- locate downwind to non plant process plant fire hazardous tank farms.

- provide proper ventilation light.

- provide sufficient space / access( bldg. Opening height and near by pipe rack
height) for Boiler erection.

- provide space for future boiler house and erection space /access for boiler.

- provide sufficient space i access (near by pipe rack height) for chimney erection.

- Locate other facilities like WTP, furnace oil storage or coal storage. ETP etc. As per
good engineering practices.

Water treatment plant:

- near to boiler house. Process plant and raw water storage. ETP.

- consider space for acid , alkali storage or separate acid, alkali tank farm.

- minimum pipe run (of bigger water lines).

- road(min 4.5m) on one side is sufficient, but fire fighting space to provided. Utility building(with compressor, chillers etc)

-Close to process plant, minimum pipe run. Locate away from admin ,office. Residential complexes(to avoid noise trouble)

- Air(pressure) vessels outside the building in open area.

- If required provide noise dampening.

- Road(min 4.5m) on one side is sufficient, but fire fighting space to provided.

Cooling towers

- Down wind to process plant, other plant i3uildings,locate in open(ventilated)
area.

- Water drift should not obstruct visibility on roads and corrode the adjacent
plants.

- Locate in crosswind direction to avoid suction discharge mixing and efficiency
reduction.

- Locate close to end user to have minimum pipe run.

- Run the cooling water headers preferably underground. if pipe rack is provided
then Pump-bay below the pipe rack.

- Road (min 4.5m) on one side is sufficient but fire fighting space to provided.
2 Pole/4 Pole structure:

- close to the plot boundary and incoming ht cable.

- away from fire prone areas like fire hazard tank farm coal / baggasse storage.

- provide pathway (1m or 1.5m) if required(road is not required).

Mitch-yard /MCC,PCC room/DG room:

- Close to process plant/utility area(can be combined with utility block).

- Minimum cable run.

- Provide sufficient space, (near by) pipe rack height road (min 4.5m) for DG panel erection.

- Locate at higher grade and above food level.

- Locate dg room away from admin. Office Residential complex. If required provide noise Dampening.

Raw water/ Fire water storage and pump house:

- Close to plant entry, in safe area near to water battery limit / tube well

- Locate at higher grade elevation and high flood level.

- Minimum pipe / cable run fire fighting lines normally underground.

- Road(min 4.sm) on one side is sufficient. but fire fighting space to provided.

- Provide sufficient erection and maintenance space.

Effluent treatment plant:

- Locate in low lying area at remote place away from process(main) plant ,non plant building ensure proximity to industrial estate ETP line.

- minimum pipe / cable run pipes/cables are run underground ,if not the on pipe sleepers

- seepage to soil should be avoided.

- pathway on one side is sufficient but fire fighting space to re provided.