Oval Hose

Oval hose is low-pressure polyethylene pipe that ships and stores flat, then rounds out once it is full of water. On a nursery it does the job of rigid PVC for submains and water transfer without trenching, glue or the freight of pipe, and unlike vinyl layflat it takes standard dripperline connectors punched into the wall.

ML Irrigation supplies oval hose from Netafim, Toro, Rivulis, Irritec and Jain in 21, 29 and 42 psi grades and sizes from 1/2" to 4" to growers in all 50 states.

Which oval hose do I need: 21 or 42 psi, and what diameter?

Start with the pressure grade. Every line here is offered at 21 psi, which is the right grade for a submain that sits downstream of a pressure regulator and feeds drip tape or dripline. Choose the 42 psi grade from Netafim or Rivulis when the hose runs ahead of regulation, straight off a pump, or on a long transfer run where start-up surge is normal. Netafim also makes a 29 psi grade in between.

Then size for flow, not for the pump outlet. Larger diameters carry a whole block and smaller ones work as laterals, which is how Jain positions its range. Rivulis goes down to 1/2", Toro Blue Stripe Oval Hose covers 1-1/2" to 3", Irritec runs 2" to 4" and Netafim 1.25" to 4". An undersized submain starves the far end of the block; the first symptom is uneven tape output.

Coil length decides how many joints you make. Rivulis coils run up to 3,000', Toro comes in 200', 300' and 450' coils, and Irritec's 4" hose ships in 131' bales, so a long run in a big diameter will need couplings.

What goes wrong with oval hose, and how do the lines differ?

The failure we see most is 21 psi hose plumbed where 42 psi belongs: upstream of the regulator, or where a closing valve hammers the line. The second is vacuum. Oval hose is flat when empty, so when a zone shuts off and drains downhill the hose collapses and pulls dirt in through the end fittings. An air and vacuum vent at the high point stops it.

Third, fittings. Nominal size does not tell you the bore: Toro's 2" hose is 2.052" ID, and published inside diameters run from 0.660" to 3.996", so match fittings to the maker's hose, not the nominal size.

The lines differ in resin, sizes and packing. Netafim Oval Tube has the widest grade choice and suits systems you pull up at season's end. Toro Blue Stripe Oval Hose is a linear low-density hose in three sizes for straightforward PVC replacement. Rivulis Oval Hose goes smallest and longest, from 1/2" hose to 3,000' coils. Irritec PE Oval Hose ships in bale-style rolls for retrieval and relocation. Jain Oval Hose is LDPE, UV-stabilized and runs about 98% round under pressure.