How to Buy a Used Grout Plant
A grout plant is a mixer, a holding agitator and a pump, and it is usually bought as a set. What the set can do depends less on any single component than on whether the three are matched to each other and to the work.
The first question is always what you are grouting. Micropiles, ground anchors and jet grouting place very different demands on pressure and continuity, and a plant that suits one may be unusable for another.
Start with the application
Anchor and micropile grouting typically wants a well-mixed, consistent grout at moderate pressure, delivered reliably. Jet grouting wants very high pressure and uninterrupted flow, and the plant is a different class of machine as a result.
Establish the pump’s maximum working pressure and its output at that pressure, not its free-flow figure. The two are often quoted interchangeably in listings and are not the same number.
Confirm whether the plant can run continuously. A batch plant that has to stop to mix will not suit work where an interruption compromises the product.
Mixer and agitator
High-shear colloidal mixers produce a more stable, better-hydrated grout than paddle mixers and are the norm for anchor and jet work. Establish which is fitted, because it is not a cheap conversion.
Check the mixer drum and paddles or rotor for wear, and look at the seals around the shaft — grout is abrasive and shaft seals are a routine failure point.
Confirm the agitator capacity is sensible against the mixer batch size and the pump output. A holding tank too small for the pump means the plant cannot run continuously whatever the mixer can do.
Pump and wear parts
Establish the pump type. Progressive cavity pumps are common for anchor and micropile work and wear through rotor and stator; piston pumps handle higher pressures and wear through seals, valves and liners.
Ask when the wear parts were last replaced and what they cost. On a progressive cavity pump the rotor and stator are consumables with a real running cost, and a plant sold just before a change is a plant with a bill attached.
Check the pressure gauges and any pressure relief arrangement actually work. On a high-pressure plant this is a safety item, not a convenience.
Power, mounting and site practicality
Confirm whether the plant is diesel or electric, and whether that suits your sites — enclosed and urban work often rules out diesel.
Establish how it is mounted: skid, trailer or container. Container-mounted plants are far easier to move internationally and are worth a premium if you work across borders.
Check the water supply and dosing arrangement. Inconsistent water measurement is the most common cause of inconsistent grout, and an automatic dosing system is worth having.
Inspection checklist
- Application confirmed: anchors and micropiles, or jet grouting
- Pump working pressure and output at that pressure established, not free flow
- Continuous running confirmed if the work requires it
- Mixer type established — colloidal or paddle
- Mixer drum, paddles or rotor, and shaft seals inspected
- Agitator capacity checked against mixer batch size and pump output
- Wear part replacement history and cost established
- Pressure gauges and relief arrangement confirmed working
- Power source suitable for your sites
- Mounting arrangement confirmed for how you move plant
- Water dosing arrangement inspected
Frequently asked questions
What is the difference between a colloidal and a paddle mixer?
A colloidal mixer uses high shear to fully wet and disperse the cement, producing a more stable grout that bleeds less. A paddle mixer simply stirs. Colloidal mixing is the norm for anchor and jet grouting work, and converting between the two is not cheap.
Can I use an anchor grout plant for jet grouting?
Usually not. Jet grouting needs much higher pressure and uninterrupted flow, and a plant built for anchor and micropile work will not deliver either. Establish the pump’s pressure and output at pressure before assuming a plant can cross over.
What are the running costs?
Mostly wear parts on the pump. Progressive cavity pumps consume rotors and stators; piston pumps consume seals, valves and liners. Ask when they were last replaced and what a set costs, and price an imminent change into the offer.
Browse grout plants on Piling Broker or read the other buyer’s guides.