Start from the water source and field layout
Start with the required flow for all irrigation zones operating together, the route length, elevation changes and pressure needed at each outlet. Show the pump, filters, valves, fittings and laterals on a layout. Main and lateral diameter ranges are not a substitute for calculating pressure losses for that layout.
LDPE or HDPE
Ask for the actual PE compound, pipe construction, governing standard and declared application. Compare flexibility, permissible bend radius, pressure capability, joining method and field exposure for that product. LDPE or HDPE alone is not a pressure rating. For outdoor exposure, require the specified UV protection and supporting evidence; do not assume a black colour or one additive description qualifies every pipe.
Match the pressure rating to the system
Read PN with its governing standard, material grade and reference conditions. ISO 4427-1 uses 20 °C as its reference temperature and provides guidance for other temperatures. Establish normal pressure, elevation effects, pump shut-off and transient pressure with the system designer, then check the allowable duty of the pipe, fittings and joints together. A generic lateral or main-line PN range cannot settle those checks.
Wall thickness and roll length
Specify outside diameter, nominal wall or SDR, tolerances and the applicable material and pressure standard. Check the resulting internal bore for the hydraulic calculation. Request available coil lengths, coil dimensions and mass, minimum bending and storage conditions, and installation handling. A longer coil can reduce planned joints but may require different handling equipment.
What to send when requesting a quote
Request a PE irrigation pipe quotation review. Send the zone layout and simultaneous flow, route lengths and elevations, outlet-pressure requirements, pump data, water and ambient temperatures, exposure, proposed grade and standard, joining method, quantity and destination. Include the designer's hydraulic and pressure requirements so the quoted pipe, fittings, coil format and packing can be checked together. The diameter and pressure guide explains the calculations and their limits.