ST-45 PUMP — HOW IT WORKS

The following is a brief explanation of how the concrete cylinders, hydraulic cylinders, shuttle tube, valves and hopper work in sequence to pump concrete.

The hydraulic pressure is generated by a variable volume, pressure compensated, axial piston pump that is driven by a diesel engine. The rod sides of the drive cylinders are hydraulically connected together creating a “slave circuit,” which allows hydraulic oil to transfer from one piston to the other.

The two part cycling sequence is initiated by an electrical signal generated by two proximity switches located in the drive cylinder. The proximity switches are normally open, magnetically sensing the movement of the main drive cylinder. As the drive cylinder piston head passes the proximity switch, an electrical signal is sent to the solenoid operated pilot valve which in turn directs pilot oil to the four valves controlling the drive cylinder and the shuttle cylinder.

A one-gallon accumulator assists the movement of the shuttle tube.This circuit assures that the shuttle tube will throw with the same intensity of each stroke regardless of how fast the main drive cylinders are cycling.

Figure 6. Pumping Cycle 2

In the first cycle, hydraulic pressure is applied to cylinder (B), causing the hydraulic piston, which is connected to the concrete piston and piston cup, to discharge concrete into the delivery line (Figure 5).

As one cylinder is discharging concrete, the hydraulic oil from the rod side (B) of the drive cylinders is being transferred through the slave circuit causing the opposite cylinder (A) to move back on the suction stroke, filling the cylinder with concrete.

The shuttle tube is sequenced to pivot to each concrete cylinder as the drive cylinders stroke to push concrete. As the second cycling sequence begins (Figure 6), the shuttle tube pivots to the opposite cylinder (A). The hydraulic piston passes under the proximity switch and sends pressure to the piston, causing it to stroke and discharge concrete into the delivery line. Hydraulic oil is transfered through the slave circuit to cylinder B, causing it to start a suction stroke, refilling it with concrete.The pumping sequence then repeats for the durration of the operation.

Figure 5. Pumping Cycle 1

MAYCO ST-45HRM PUMP — OPERATION & PARTS MANUAL — REV. #4 (07/16/04) — PAGE 19

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Multiquip ST-45HRM manual ST-45 Pump HOW IT Works, Pumping Cycle
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ST-45HRM specifications

The Multiquip ST-45HRM is a highly versatile and robust soil compactor designed for various construction applications. With its advanced engineering and innovative technologies, it sets a new standard in the compaction equipment market. This model is particularly favored for its reliability, durability, and exceptional performance in both small-scale and large-scale projects.

One of the standout features of the ST-45HRM is its powerful engine. Equipped with a high-performance, fuel-efficient diesel engine, it delivers ample power while ensuring reduced fuel consumption. This results in not only lower operational costs but also decreased environmental impact, aligning with today's sustainability goals.

The compactor's dual-directional capability allows for efficient operation in compacting various soil types. Whether tackling granular, cohesive, or mixed soils, the ST-45HRM adapts seamlessly, ensuring optimal performance. Furthermore, it features a unique vibratory system that maximizes compaction efficiency, enabling faster job completion and minimizing the number of passes required.

Operator comfort and safety are paramount in the design of the ST-45HRM. The machine is equipped with an ergonomic operating platform and intuitive controls, allowing for easy maneuverability even in tight spaces. The advanced vibration dampening technology significantly reduces operator fatigue, making long hours of operation more manageable.

Additionally, the ST-45HRM offers impressive maneuverability, thanks to its compact size and precise control. This is particularly beneficial for working in confined areas, such as urban construction sites where space is limited. Its robust construction ensures it can withstand the rigors of challenging job sites while maintaining performance.

Maintenance is made simple with the ST-45HRM. The design allows for easy access to key components, reducing downtime and enhancing productivity. Regular service intervals and the use of quality materials ensure the longevity of the machine, making it a smart investment for contractors looking for reliable and efficient compaction equipment.

In summary, the Multiquip ST-45HRM combines powerful performance, innovative technology, comfort, and ease of maintenance into a single, versatile package. It is an ideal choice for contractors seeking a dependable soil compactor to meet the demands of various construction projects. With its impressive features and capabilities, the ST-45HRM stands out as a leader in the field of soil compaction.
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