Green Guru LLC — Irrigation & Landscape Lighting

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Pressure Discipline

Caleffi 535 PRV (1" union)

If your source pressure is consistently high (often 85+ PSI in parts of Rochester), a properly sized pressure reducing valve (PRV) can protect the system and reduce misting waste. Our common one-inch union option is the Caleffi 535.

Union serviceability 1" class installs Tuned to 65 PSI Scoped on-site

What a PRV solves (in plain language)

  • Misting waste: excessive pressure can atomize sprays/rotors and blow water off-target.
  • Water hammer + wear: pressure spikes and high baseline pressure accelerate failures in valves, fittings, and heads.
  • More repeatable tuning: stable supply pressure keeps nozzle performance closer to the chart and reduces seasonal drift.
Important: A PRV is an add-on for pressure discipline—it is not a native requirement of SRMS™. SRMS tiers are built around connectivity and control (and response when paired with service plans). See SRMS™ for scope clarity.

How we scope a PRV install

  • Measure static + dynamic pressure: we care about pressure under flow (not just the no-flow reading).
  • Confirm peak zone demand: rotor and spray zones are sized differently; we set the PRV to protect the highest-demand zone while keeping coverage clean.
  • Confirm fit: backflow model, clearances, unions, winterization approach, and service access all matter.

Related pages

Availability

We confirm fit and compatibility during service and can supply or install owner-supplied hardware.

At a glance

Caleffi 535 facts
IndustryIrrigation
BrandCaleffi
Series535 (PresCal)
Connection1" FNPT union
Example parts535360HA (no gauge), 535361HA (with gauge)
Adjustment range15–90 PSI (manufacturer specs)
Maximum flow19 GPM (manufacturer specs for 1" union model)
Max operating pressure300 PSI (manufacturer specs)
Max working temperature180 °F (manufacturer specs)
Where it goesCommonly installed in the PVB/backflow downleg when scoping allows (site-specific)

Pressure issue suspected?

We can test pressure at the source and under flow, then scope the correct mix of PRV, pressure-regulating heads, and programming changes.

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Related: Irrigation upgrades.