The time is May. In Rajasthan, Maharashtra and Madhya Pradesh, Kharif crops – cotton, soybean, groundnut, maize are sown June-July. Farmers that are putting in or expanding sprinkler irrigation systems now have the time to do it well. Anyone waiting until the first week of June is ordering from depleted stock, taking whatever sizing the dealer has available, and then asking why their system pressure drops down on the far end of the field.
Here is the practical approach to sizing sprinkler pipe fittings for kharif 2026 and, more importantly, the five size blunders that cost more to rectify after installation than to prevent pre-installation.
5 Sizing Mistakes That Kill Kharif Irrigation Performance
Mistake 1: the lateral diameter is too small.
The most frequent mistake. A farmer with a 5 acre cotton field utilizes 20mm laterals for a 90 metre line to save on pipe cost. As water gets to the last sprinkler head on the lateral, pressure drops 35% of the initial head. The last 20 metres of the field receive 40% less water than the first 20 metres. Cotton yield falls. The farmer blames the pump, but it’s the lateral diameter that’s the problem.
The fix: Where laterals are longer than 60m and operating pressures are 2.5 – 3.0 bar, change from 20mm to 25mm laterals or use pressure compensating sprinkler heads. The difference in cost for the pipe is only ₹4-6 per metre, which is significantly less than the loss of production due to unequal irrigation.
Mistake 2: Incorrect Coupler Type for Seasonal Systems
Sprinkler systems are portable and are set out at planting and taken up after harvest. Using electrofusion couplers on portable laterals will make the system non repositionable fused connections cannot be moved. Cheap push fit couplers not suitable for the system pressure will create leak spots on every surge event when the pump starts or stops.
The fix: Use portable lateral joints with PP compression couplers as per IS 17425. Tool free, rated for the pressure range of farm sprinkler systems, and reversible for seasonal collection and storage. Arihant Plast offers a complete variety of HDPE Sprinkler fittings with the right compression coupler characteristics for all typical lateral diameters.
Mistake 3 – Not considering fitting pressure ratings
A farmer buys 20mm HDPE pipe rated SDR 13.6 (PN 8) but uses cheap unrated fittings that blow at 4 bar. The system is generally functioning at 3.5 bar fine. But pump start up pressure goes up to 5-6 bar for a short time. The fittings break. The field is flooded. The pump runs dry and burns up.
The fix: Every fitting on the sprinkler pipe should have IS 17425 mark to ensure the pressure class. Buy from ISO 9001:2015 Certified Manufacturers. Every batch of fittings from Arihant Plast comes with batch paperwork that confirms the pressure rating for that production lot.
Mistake 4: Ignoring TEE and Elbow Losses
Each tee and elbow in a sprinkler system results in a pressure loss due to turbulence. If the system design does not take into account the pressure losses due to fittings, sprinkler heads will underperform at every branch point and change of direction. For example, a 5 acre farm system with 12 TEEs and 8 elbows on the submain network can have a total fitting pressure loss of 15-20% of the available pump pressure the equivalent of pushing the whole submain 100-150 metres further away from the pump.
The fix: Add 10-15% to the friction loss predicted for straight pipe runs to particularly account for fitting losses. If the system has multiple changes of direction, utilize a hydraulic design tool or refer to the sprinkler system manufacturer’s design handbook before confirming pipe and fitting sizes.
Mistake 5. Not checking IS 17425 certification before ordering
The sprinkler system shall be eligible for 55-90% subsidy under Pradhan Mantri Krishi Sinchai Yojana (PMKSY) plan of India, if components used are IS certified and sourced from BIS registered manufacturers. Farmers using uncertified fittings from the cheapest local provider are not entitled to claim subsidy losing significantly more in subsidy than they saved in the fitting price.
The fix: Check each sprinkler pipe fitting for IS 17425 marking before you buy. Ask for the manufacturer’s BIS license number and verify it in the BIS online database. Arihant Plast sprinkler fittings are IS 17425 certified paperwork provided for PMKSY subsidy claims
Frequently Asked Questions
Q1: For a 5 acre farm sprinkler system, the mainline diameter should be 3/4 inch.
Ans: For a 5 acre farm with a standard 5-HP pump providing 25,000–35,000 LPH, a 63mm HDPE mainline (SDR 13.6 or SDR 11, PE 100) will meet the flow velocity requirement of 1.2–1.5 m/s. Submains are often 50mm and laterals 20mm or 25mm depending on run length. Always verify using a hydraulic calculation using your actual pump curve.
Q2: PMKSY subsidy rate for sprinkler irrigation in Rajasthan 2026 is 50%.
Ans: The subsidy rate for sprinkler irrigation in Rajasthan is 55% (general farmer) and 75% (SC/ST farmer) in 2026 under PMKSY. Subsidy is given on the system cost up to the normative cost per hectare fixed by the state agriculture department. Systems shall be designed using IS certified components from BIS registered producers.
Q3: Are Arihant Plast’s HDPE sprinkler pipe fittings compatible with all HDPE pipe brands?
Ans: Yes, assuming the outside diameter of the pipe matches the fitting bore requirement. HDPE pipes are made as per IS 4984 or IS 17425 with standardised ODs Arihant Plast fittings are manufactured on identical OD standards and would fit on any IS specified HDPE pipe of same nominal size.
Q4: What is the minimum order quantity (MOQ) for B2B sprinkler fitting buying from Arihant Plast?
Ans: Minimum order quantities vary according on product type and size. For bulk procurement of the kharif season, please contact arihantplast.in/b2b-enquiry/ with Bill of Materials (BOM) for the project and Arihant Plast’s staff will give bulk price tiers and logistical coordination for field delivery.
