Grouting Machine Buying Guide: PU vs. Cement, Pressure Requirements, and Maintenance Essentials

Grouting machines are essential tools in waterproofing, structural crack repair, and tunnel leakage control. Whether the project involves PU injection, cement-based grouting, or injection-type epoxy resin, choosing the right machine significantly affects efficiency and long-term repair performance. This guide summarizes key purchasing questions, compares major grouting machine types, recommends pressure settings, and includes a model selection table to help you choose the right equipment.

1. Can one grouting machine be used for both PU and epoxy injection?

Yes. Some high-pressure grouting machines are compatible with both materials when properly cleaned after each use. For example, Saking’s F-512 High-Pressure Grouting Machine supports PU resin, hydrophilic PU, hydrophobic PU, and injection-type epoxy resin. Cleaning with a dedicated solvent after operation prevents residue buildup.

Different materials should be paired with the correct consumables, such as mechanical packers, high-pressure injection needles, steel or aluminum injection heads, and low-pressure cartridges to ensure accurate filling and reliable sealing.

2. What is the difference between piston-type and screw-type (extrusion-type) grouting pumps?

Piston-Type Machines (e.g., F-512 and F-612) provide stable high-pressure output, ideal for PU resin, hydrophilic polyurethane, hydrophobic polyurethane foaming agents, and epoxy injection.

Screw-Type Extrusion Equipment (e.g., F-230 Mortar Extrusion Machine) is designed for continuous delivery of high-viscosity cement-based grout. It is suitable for non-shrink mortar injection, wall cavity repair, and smoothing applications.

For a deeper comparison between the two piston models, see: F-512 vs. F-612 High-Pressure Grouting Machines.

3. What pressure and flow rate are required for high-rise or large-scale grouting projects?

For vertical structures, deep cracks, or high-rise buildings, recommended specifications include:

• Pressure: 3,500–8,000 psi
• Flow Rate: PU approx. 1–2.5 L/min; cement grout up to 16 L/min

The F-612 High-Pressure Grouting Machine meets these requirements and is widely used in metro tunnel leakage control and structural reinforcement projects.

4. How can pressure be controlled effectively during PU injection?

PU injection requires precise pressure control to prevent underfilling or excessive foaming. A suitable grouting machine should include:

• Adjustable pressure control valve
• High-accuracy pressure gauge
• Reinforced piston drive system

Saking’s piston-driven machines are built for stable and consistent pressure output, ideal for PU injection and leakage control applications.

5. Will PU resin clog the machine?

Yes. PU resin hardens quickly and may clog internal pathways if not cleaned immediately.

• Clean immediately after completion
• Use dedicated PU cleaning solvent
• Avoid leaving resin in hoses for extended periods

For high-mobility jobsites such as tunnels or basements, Saking recommends using the battery-powered F-512 version for better flexibility.

6. What is the correct cleaning process after PU injection?

Standard cleaning procedure:

1. Remove the material supply hose
2. Run the machine briefly with cleaning solvent
3. Wipe the machine exterior and lubricate piston components

This applies to all electric, high-pressure, and dual-material grouting machines.

7. Does Saking provide consumables and spare parts?

Yes. Saking offers a complete selection of consumables, including:

• Mechanical packers, high-pressure needles, aluminum injection heads, low-pressure cartridges
• Batteries and motor components for cordless models
• Original spare parts for all Saking grouting machine models

8. Does Saking offer training and operational guidance?

Yes. Saking provides online instructional videos as well as on-site training to ensure professional and safe operation.

9. If the jobsite already has an air compressor, is additional equipment needed?

If an air compressor is available, the F-230 mortar extrusion machine can operate directly without needing an additional electric motor.

For sites without electricity or compressed air, Saking’s electric or battery-powered grouting machines provide greater flexibility.

10. Does Saking offer warranty and after-sales support?

Yes. All grouting machines include a one-year factory warranty and long-term support:

• Online troubleshooting assistance
• Long-term availability of spare parts
• Repair services for older grouting machines
• Support for spraying equipment such as airless sprayers

Grouting Machine Selection Table

Conclusion: Choose the Right Grouting Machine for Better Efficiency and Quality

When selecting a grouting machine, consider the following factors:

• Material type: PU resin, epoxy, cement grout, non-shrink mortar
• Jobsite conditions: available space, power supply, mobility requirements
• Maintenance convenience: cleaning ease, consumable availability, after-sales support

Saking provides a full range of grouting solutions, including high-pressure injection systems, leakage repair equipment, cement grouting machines, PU resin materials, and spraying systems. With proven industry experience and reliable performance, Saking is your trusted partner for professional grouting applications.

For expert recommendations or customized model selection, feel free to contact Saking Industrial.