By PREMAL RAJNIKANT BHATT
As a dedicated farmer, its vital to know different components and fittings related to irrigation.
These include PVC, GI, Brass and HDPE fittings. They are more precious when farmers want to connect irrigation pipes professionally.
Most countries use the metric system, which involves measuring units such as metres and grams and adds prefixes like kilo, milli and centi to count orders of magnitude.
In the US, they use the older imperial system, where things are measured in feet, inches and pounds. These irregularities in units and insufficient manufacturer information always bring confusion and thus blind purchase of materials leading to waste of time and money.
Also, there is difference in threaded fittings, National Pipe Thread (NPT), use and most popular type of seal for pressure calibration systems in the US and Canada.
British Standard Pipe (BSP) is most popular in the UK, Europe, Asia, Australia, New Zealand and South Africa. They are almost the same except one or two things like angle of threads are different in NPT and BSP.
As a farmer, rather than use imperial or matric units, it’s always good to have an idea about or recognise these standards. Most of our irrigation fittings are in mm (Matric) and thread in BSP.
How to measure the right pipe size
All pipes should have printed size (either in inch or mm). However, these prints fade and it is sometimes hard to recognise the size by farmers.
If you have existing PVC/HDPE pipes, and would like to take connection out from it but you don’t have correct pipe size, you will end up with wrong purchase.
Try out the following method to recognise pipe size. PVC/ HDPE pipes are measured by the Outside Diameter (OD), not the inside diameter.
Wrap a piece of string or wire on top of the pipe once, measure the same piece against the ruler measurements in centimeters (cm).
This cm multiply by 10 and then divided by 3.14 to get the pipe size in mm. Also, light, medium or heavy duty pipes have the same OD, but inner diameter becomes smaller as one moves from lighter to heavier class pipes.
As a layman, the good rules of thumb are: 1) All threaded fittings are measured in inches.
2) Materials which require glue (PVC) like pipes, ball valves or compression ring (HDPE) for connection are mm.
3) In-between the above two, there is third category that also exists, mm x inch meaning either they require glue/compression ring on one side and the other thread. Male thread or female thread terms indicate position of thread either outside or inside respectively.
Again remember, most of our irrigation fittings are in matric and BSP standard but you can come across imperial fittings as well.