XG(H) Gravel Pump vs. Standard Slurry Pump Structural Differences: Single Casing vs. Double Casing – Which Is Better for Large Particle Transport?

Subtitle: From casing design, flow passage to maintainability – a comprehensive comparison for coarse, abrasive slurries

Introduction

In applications such as river dredging, sand mining, and tailings transport, selecting the right pump for large‑particle, high‑concentration slurries is critical. The XG(H) series gravel pump and standard slurry pumps (e.g., AH, ZJ, ZGB series) differ fundamentally in design: XG(H) gravel pumps use a single casing with clamp connection, while standard slurry pumps use a double casing with bolted connection. This difference leads to distinct performance in large‑particle handling, maintenance convenience, and wear life.

Many users are confused: single casing or double casing – which is better? As a professional slurry pump manufacturer, this article compares the two designs from the perspectives of casing structure, flow passage, repair access, and particle size capability, helping you make the optimal choice based on your material.

1. Basic Definitions of the Two Designs

2. Single Casing (XG/H) Design Features and Advantages

2.1 Wide Flow Passage

The XG(H) gravel pump has an extremely spacious pump chamber with wide impeller passages and streamlined casing. This allows it to pass particles up to 150–260 mm (depending on model), while standard slurry pumps typically pass ≤80 mm. For slurries containing cobbles, gravel, or large sediment, the single‑casing design has an irreplaceable advantage.

2.2 Clamp Connection for Fast Maintenance

The casing and cover are joined by a clamp with an O‑ring seal. Simply loosening the clamp bolts allows quick access to the impeller and wear parts. Compared to removing dozens of bolts on a double‑casing pump, maintenance time on a single‑casing pump can be reduced by more than 50% – ideal for frequent field service.

2.3 Single‑layer Wear‑Resistant Casing

The casing itself is the wear part, typically cast from high‑chrome iron. Although replacement cost is higher, the thick, wear‑resistant casing provides good life under coarse particle impact. Larger models may also have replaceable liners.

3. Double Casing (Standard Slurry Pump) Features and Advantages

3.1 Replaceable Liners – Lower Long‑Term Cost

The outer shell of a double‑casing pump is a pressure‑containing part (cast iron or steel), while the inner liner is made of high‑chrome alloy or rubber. When the liner wears, only the liner needs replacement – the shell is reused. For fine particle, high‑concentration, long‑term continuous operation, double‑casing pumps offer lower lifecycle spare parts cost.

3.2 Higher Sealing Reliability

Double‑casing pumps use bolted connections with uniform gasket or O‑ring compression, providing higher pressure capability (>2.5 MPa). Clamp seals on single‑casing pumps may leak under very high pressure.

3.3 Efficiency Optimization Potential

Double‑casing pumps typically have more refined hydraulic designs, achieving higher peak efficiency (>70%). For fine particle slurries, they consume less energy.

4. Core Comparison: Large Particle Handling Capability

Conclusion: For applications requiring transport of large particles (>80 mm), the single‑casing gravel pump is the only choice. For smaller particles (<50 mm), double‑casing pumps are more economical.

5. Maintenance Convenience Comparison

Guidance: If field maintenance capability is limited or frequent clog clearing is needed, the single‑casing pump is better. If long‑term operating cost is the priority, double‑casing pumps are superior.

6. Selection Decision Matrix

7. Case Study: Pump Selection for a River Dredging Project

Background: River dredging required transporting slurry containing cobbles (up to 120 mm) over 1.5 km at 45 m head.

Selection: XG 10/8 gravel pump (single casing) with clamp connection.

Results:

• No clogging for 6 months

• Each inspection took only 30 minutes to open cover

• Wear part life 4,000 hours

If a standard slurry pump had been used: Expected clogging 1‑2 times per week – continuous operation impossible.

Conclusion

XG(H) gravel pumps (single casing) and standard slurry pumps (double casing) have clear application boundaries. Single‑casing gravel pumps excel in wide flow passages, fast clamp opening, and超大 particle handling – they are the only choice for large‑particle transport and frequent maintenance. Double‑casing slurry pumps feature replaceable liners, higher efficiency, and lower long‑term operating cost – ideal for fine particles, high concentration, and continuous long‑term operation. The primary selection criterion is the maximum particle size: if particles >80 mm, choose a single‑casing gravel pump; if particles <50 mm, prefer a double‑casing slurry pump.

As a professional slurry pump manufacturer, we offer both XG(H) gravel pumps and full‑range double‑casing slurry pumps, with free selection consulting based on your material characteristics. Please contact our technical team.