Rivulis Air & Vacuum Release MPT 1" - (Air Valves)

What It Does

The Rivulis Air & Vacuum Release Valve performs two distinct jobs in a single compact body. On system startup, it stays open to exhaust large volumes of trapped air as water fills the mainline and laterals — allowing pipes to prime quickly without pressure spikes or water hammer events. On shutdown, it re-admits air to the distribution system, breaking the vacuum that would otherwise cause pipe collapse or suck substrate and media particles back through the emitters.

This is a dedicated Air & Vacuum (kinetic) valve, meaning its float-based mechanism is optimized for high-volume air movement at the beginning and end of each irrigation cycle. It is not a continuous (automatic) air release valve — it handles the big air events, not micro-bubble bleed during pressurized operation. If your design requires continuous bleed under pressure, Rivulis also offers Continuous and Combination valve types in their line.

Who Needs This

Any commercial cannabis or hemp operator running a closed drip or micro irrigation system should have air valves designed into the header. This is especially relevant for multi-zone fertigation builds where zones are cycled on and off repeatedly throughout the day — each on/off event creates an air introduction or vacuum event at the lateral ends and high points in the mainline.

Indoor and greenhouse operators growing in coco, rockwool slabs, or other inert media are particularly exposed to emitter suck-back on shutdown. A single vacuum event pulling substrate fines into a dripper orifice silts up that emitter and creates a dry spot in the canopy. At scale, undetected dry spots translate directly to yield loss and irrigation uniformity problems. Placing this valve at the high point in each zone loop is standard practice in well-designed fertigation systems.

Key Features

The valve body is manufactured from premium resins engineered for long-term UV and chemical resistance — relevant in greenhouse environments where nutrient solutions, sanitizers, and UV exposure are routine. It is rated compatible with both metal and plastic pipe systems, giving flexibility across PVC mainline, poly submain, and drip tape lateral configurations.

The float mechanism is designed to remain open under high air pressure during startup, fully exhausting the pipe before the float seals. Once water reaches the valve, it closes and maintains a drip-tight seal at water pressures as low as 3 psi — low enough to stay sealed across the full range of regulated drip system pressures. The 1" MPT male thread connects directly to a standard 1" FPT tee fitting, which should be positioned at the highest point in the zone or just downstream of the zone control valve.

How It Fits a Commercial Grow Build

In a typical multi-zone fertigation skid design, each zone valve feeds a submain that branches into drip laterals. The correct placement for this air valve is on a tee at the highest elevation point of each zone's submain — that is where air naturally accumulates and where vacuum forms first on shutdown. One valve per zone is the standard minimum; on longer runs or systems with significant elevation changes, additional valves may be warranted at intermediate high points.

For operators running subsurface or flush-to-media dripper configurations (common in coco slabs and rockwool), the suck-back protection function is critical — not optional. This valve pairs cleanly with Rivulis drip tape, dripline, and emitter products available through HSC's irrigation catalog, making it straightforward to spec the full zone from header to emitter in a single quote. Contact HSC to get a quote on this valve alongside any other Rivulis irrigation components for your build.