Section 27 · Install & Run
Installation & siting
A ram forgives mediocre pumps and punishes sloppy civil works. Most "my ram won't run" stories end at the intake, the drive pipe, or the anchor — so build those three like you mean it.
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Choosing a site
The ideal site has: a reliable source with ≥ 1 m of fall (more is power), spare flow beyond your demand — remember the waste is the fuel — a short, straight route for the drive pipe, flood-free ground for the pump, and a sensible path for the delivery line. Before falling in love with a spot:
Streams are usually owned by someone and regulated by something. Confirm water rights or abstraction rules in your jurisdiction, and always leave the stream's environmental flow — fish and downstream neighbours were there first.
Measuring fall & flow
- Fall (H): vertical distance from the source water surface to the ram's waste valve. A clear hose filled with water between two stakes (a "water level") reads level to within a centimetre over hundreds of metres; a clinometer or a phone's level app works too. Measure to the source surface at working level, not flood level.
- Lift (h): same trick, ram to delivery-tank water surface.
- Flow: the bucket-and-stopwatch is exact enough — time how long a 10 L bucket takes to fill from the full pipe/channel. For open channels, time a floating object over a measured distance and multiply the cross-section by the surface velocity (× ~0.85 to correct for channel drag).
- Measure in the dry season. A ram designed for April flows starves in August. If the spare flow varies 5× across the year, design for the low month.
Intake & forebay
The intake's job is to hand the drive pipe solid water with no air and no grit — the two things that stop a ram. A small forebay (settlement tank) at the source makes this almost automatic:
- Screen the outlet: 1–2 mm mesh, cleanable, sized ~10× the pipe area so partial clogging doesn't starve the pump.
- Submergence: keep the pipe mouth at least 2–3 pipe diameters below the surface, and off the bottom, or it will gulp air, then silt.
- Settling depth & volume: enough quiet water for grit to drop out; a minute or two of drive flow is plenty.
- Overflow & spillway: the forebay must pass excess flow around the ram, especially when the pump is stopped.
- Access: you will clean this screen; make it easy.
Routing the drive pipe
The drive pipe is the engine's flywheel — treat it accordingly:
- Rigid steel preferred; heavy pressure-rated PVC acceptable on some sites. No hose, ever (see why).
- 3–7 × H long, constant diameter, never reduced mid-run.
- As straight as the land allows; where bends are unavoidable, smooth large-radius curves, not elbows.
- No high points: a monotonic fall from intake to pump. A sag that traps air is a cushion that will stop the beat.
- Watertight and airtight: drive-side joints see suction pulses; a leaky thread ingests air with every beat. Use glands, unions and sealant properly.
- Anchored or buried: the pipe must not flex or creep with each slam. Trench below frost depth where freezing is a thing.
- If you need a shutoff, use a free-flow type — gate or full-bore ball valve, never a restrictive globe.
Mounting the ram
- Concrete pad (or an immovable timber crib) with hold-down bolts: a ram beats ~80,000 times a day; anything loose walks.
- Above flood level and above the waste water's splash zone.
- Waste channel: carry the spill clear of the foundation and the neighbour's path. Bonus points: lead it to a pond, irrigation channel or reed bed — it's clean water, just spent.
- Access & noise: leave room to kneel and wrench. The clack is part of the charm; a timber cover or pit housing tames it if it isn't.
The delivery line
Delivery is forgiving: the air chamber isolates the line from the hammer, so HDPE or pressure-rated PVC is fine. Size it for low friction on long runs (typically around half the drive pipe's diameter; larger for distance). Ensure the pressure rating exceeds the full static head with margin — if the chamber ever fails, the line sees raw slams. Bury it or protect it from UV, rise steadily to the tank, and fit a small overflow so a stuck float can't flood the hillside.
Commissioning checklist
- ☐ Screen clean, pipe mouth submerged, forebay settling quietly
- ☐ Drive pipe purged — water runs from the open waste valve with no spitting
- ☐ Every drive-side joint dry (remember: airtight, not just watertight)
- ☐ Air chamber charged; snifter bubbling once the beat settles
- ☐ Waste valve tuned: steady beat, roughly 30–100 per minute
- ☐ Delivery valve opened gradually — dumping it can stall the cycle
- ☐ Delivery measured at the tank matches the design estimate
- ☐ Waste water channeled away; anchors torqued; pad dry
- ☐ Revisit after one week to re-tune and hunt the slow leaks
Winter & drought
Cold: moving water freezes reluctantly, so a ram running 24/7 can survive moderate winters if the intake, drive pipe and pad are below frost depth and the delivery line drains or is buried. Where hard freezes are certain, drain the system before the first hard frost — ice splits chambers and bodies without malice. Drought: if the source drops, reduce the drive flow or lighten the valve rather than letting it gulp air; if the intake surfaces, stop the pump and wait for rain. A ram abandoned dry for a season suffers no harm at all — one more virtue.
When it's beating on its own, the Maintenance schedule is all that stands between you and twenty years of free water.