Jobe Topaz Partfill Float Valve – Water Tank Float Valve for Rainwater Harvesting Tanks & Cisterns

Ships directly from the manufacturer.

The Jobe Topaz Partfill Float Valve is a high-flow water tank float valve built for rainwater harvesting tanks. During dry spells it automatically keeps a low reserve of water in the tank from your mains or pump supply — so the services fed by the tank keep running, while leaving capacity for the next rain to fill.

Here's how it works: as the tank empties, a weighted float travels down its cord and sits on the bottom stop, which opens the valve. The valve runs until the float lifts clear of the stop. When it rains, the float simply rises and falls with the water on its 8.2 ft (2.5m) cord — so the Partfill only tops up when rainfall isn't enough to keep the level above the bottom stop.

The valve installs through the side wall of the storage tank, mounted above the overflow level to prevent backflow, and Jobe rates it for all makes and models of rainwater harvesting tanks. It's available in 1/2", 3/4", 1" and 1-1/4" inlets, all supplied with a long tail, backnut and seal washer.

The Partfill is compact, built from non-corroding materials with 304 stainless steel hardware, locks off with a lock-off switch, and uses Jobe's patented Detach Valve Seal Access System for quick access to the valve seal.

Features

Keeps a Low Reserve
Maintains a minimum water level during dry periods while leaving room for rainwater.

Only Runs When Needed
Tops up only when rainfall can't keep the level above the bottom stop.

Side-Wall Mounting
Installs through the side wall of the tank, above the overflow level.

Lock-Off Switch
Lock the valve in the off position whenever you need to.

Detach Valve Seal Access
Jobe's patented Detach system gives quick access to the valve seal.

Which Size Is Right for You?

1/2" Long Tail
3-15/16" thread length, with backnut and seal washer.

3/4" Long Tail
1-13/16" thread length, with backnut and seal washer.

1" Long Tail
2-7/16" thread length, with backnut and seal washer. More flow than the 3/4" at the same pressure.

1-1/4" Long Tail
2-21/32" thread length, with backnut and seal washer. The largest inlet, with more flow than the 3/4" at the same pressure.

Specifications

Inlet Sizes: 1/2", 3/4", 1", 1-1/4" (long tail)
Long Tail Thread Length: 1/2" – 3-15/16" | 3/4" – 1-13/16" | 1" – 2-7/16" | 1-1/4" – 2-21/32" (backnut & seal washer included)
Operating Pressure: 5–150 psi (0.3–10 bar)
Max Temperature: 140°F (60°C)
Level Differential: Up to 6" (150mm), depending on pressure
Float Cord: 8.2 ft (2.5m)
Mounting: Through the tank side wall, above the overflow
Materials: Glass-filled nylon body, EPDM diaphragm, TPU seal, HDPE float, 304 stainless steel hardware

Jobe Topaz Partfill Spec Sheet (PDF)

Frequently Asked Questions

Will the Partfill fill my whole tank?
No — that's the point. It keeps a low reserve so services fed by the tank keep running, and leaves the rest of the tank's capacity for rainwater.

Where does it mount?
Through the side wall of the storage tank, above the tank's overflow level to prevent backflow.

What supply does it run from?
Mains or pump-supplied water, from 5 psi (0.3 bar) up to 150 psi (10 bar).

Need to fill a pump-supplied tank all the way?
See the Jobe Topaz Differential Float Valve.

Save the space for the rain, keep the water flowing — the Jobe Topaz Partfill takes care of the dry spells.