SCALE FACTORS IN

PIPELINE ENGINEERING

DESIGN

Presented by Y.Muthuraman

M.Tech PLE(R150214029)

What is Scale factor ?

Scale Factor(SF) =

SF-Scale factorAS-Distance between the two points on MapPS-Distance between the two points in the Earth

Cartographers

Why we need Scale factor ?

Scale Factor in Pipelines Scale factor differs from one location to another.

We need to cover the entire ROUTE OF PIPELINE (From Source Station to Transmission Station) by calculating the Scale Factor which varies with respect to Map Projection terrain or plane or valley or any location.

Distortion and Scale factor• Longitudes starts from 0 degree meridian

line, all the longitudes forming same diameter circles on the earth.• Latitudes starts from 0 degree Equator line,

all the latitudes forming the circles, whose diameter goes on decreases, towards North & South pole.

Distortion and Scale factorEarth has different Circumference(2πr)

Distortion

Scale factor differs for every latitude

•

Map Projection• A plane is placed tangent to the Earth’s

Surface• The points are projected from the centre of the

earth to the plane gives us the parallel lines(lattitude).• Earth looks from centre point of view and

projected on to the plane and creates the image on chart/map.

CYLINDRICAL/mercator PROJECTION Cylinder placed around the equator and

makes tangent plane. Plane contains parallel lines(line at which

cylinder is tangent to equator) and projections of meridians, both maintains the same diameter in all the circles of latitude

No distortion in circumference of Earth’s Surface

Lambert Conformal Projection• Best method for mapping the pipelines mostly

preserving the • Maxi. Scale Error of 2.5%

Shape of the features Directions of the RouteDistances between two pointsAreas to be located

Requirements for Scale Factor

Pipelines having different scenarioElevation, Compresssor station, buried pipeline , subsea pipeline , forest, roads , streams1. Positioning of respective elevation 2. Datum point , 3. Latitude coordinate, 4. Longitude coordinate , 5. Eccentricity from parallel lines

Steps to calculate the Scale factor for Routing the pipeline • Set the Central Meridian in your source station of

pipeline.(Eg. Pipeline layed from 12degree WEST to 36 degree EAST)• Set the standard Parallel lines within the site starts from

central meridian with the spacing of latitudes 6 degree interval.

(Eg. 12W – 36E have the range of 24 degree)So, each latitude spacing = 24/6 = 4 degree of latitude

Steps to calculate the Scale factor for Routing

the pipeline• Convert the latitude degree into Radians for

calculating the scale factor(k).• k = ( sqrt(1.0 - e2*sin(lat)*sin(lat))/cos(lat) ) *

( cos(lat1)/sqrt(1.0 - e2*sin(lat1)*sin(lat1)) ) 

e2 = eccentricitylat = latitude of pointlat1 = standard parallel

Map Scale & True Scale for Routing of Pipeline•Multiply the Scale factor with Map Scale and

get the True Scale value of the real world• Scale Factor Distortion is minimized by getting

scale factor from Lambert Conformal Map Projection

X,Y values from Map projection

Central meridian value

Height and width of routing area

By typing the Scale Factor we can change the Scale ratio of :

Scale factor for different Areas

Conclusion• Hence the scale factor depends on the type of map

projection for different areas, which are going to be considered for routing the pipelines.• Area may be having Elevation , Roads, Stream,

Subsea, Terrain, Forest , Protected Areas, Valley , Rivers.• Scale factor varies and also scale distortion is

reduced.