The provided source materials focus on the technical specifications, features, and commercial details of double-acting hydraulic jacks, primarily for heavy-duty applications such as trailer lifting and industrial use. These documents are sourced from manufacturer and retailer websites, offering product descriptions, component lists, and operational guidelines. The information is geared towards commercial and industrial buyers rather than consumer free sample programmes, promotional offers, or no-cost trials. Consequently, the following article synthesises the available technical and commercial data on double-acting hydraulic jacks, presenting it in a structured format relevant to UK-based consumers, tradespeople, and enthusiasts seeking reliable product information.
Product Overview and Core Components
Double-acting hydraulic jacks are designed for applications requiring both powered lifting and lowering, providing greater control and speed compared to single-acting models. The source materials describe several kits and individual components suitable for various heavy-duty tasks, including trailer maintenance, construction, and industrial lifting.
A typical double-acting hydraulic jack kit, as detailed in the sources, includes several key components: - Hydraulic Power Unit (HPU): A double-acting pump that supplies hydraulic fluid under pressure for both the extending (raising) and retracting (lowering) phases. For instance, one kit features a power unit with a 3,200 psi relief setting on the extend port and a 1,500 psi relief setting on the retract port. - Hydraulic Cylinders/Jacks: These are the lifting elements, often rated for significant capacities. For example, a 24,000 lb lifting capacity kit comprises two 12,000 lb jacks with 2" x 20" cylinders. - Control Mechanisms: A remote pendant (e.g., a 15-foot power-up/power-down pendant) is commonly included for user convenience and safety. - Supporting Hardware: This encompasses hydraulic hoses (e.g., 48" hoses with #6 JIC fittings), fittings (tees, elbows, adapters), battery cables, and a flow divider to ensure synchronized operation of multiple jacks. - Additional Features: Some kits may include a rubber strap for securing the jack and optional solar or AC chargers for the power unit.
Key Specifications and Performance Metrics
The technical data provided across the sources outlines critical performance metrics for these hydraulic systems. These specifications are essential for determining suitability for specific tasks and ensuring safe operation.
- Lifting Capacity: Systems are available with varying capacities. A notable example is a kit with a total lifting capacity of 24,000 lbs, delivered by two individual 12,000 lb jacks. Another source mentions double-acting cylinders with capacities ranging from 10 to 500 tons, with higher capacities available upon request.
- Pressure Settings: Relief valve settings are crucial for safety. Common settings include 3,200 psi for the extend port and 1,500 psi for the retract port, as noted in multiple sources. One product specifies a safety pressure relief valve in the return port to prevent over-pressurization during retraction.
- Stroke and Dimensions: Jacks are described with specific strokes (e.g., 6" to 20.13" for industrial cylinders) and maximum heights. For trailer jacks, the maximum distance from the ground to the bottom of the trailer frame is often around 8 inches.
- Hydraulic Flow and Fluid: The maximum hydraulic flow rate is typically around 2 GPM (gallons per minute), with some systems operating within a 1-5 GPM range. The recommended fluid type is Automatic Transmission Fluid (ATF), specifically non-synthetic, as indicated in one specification sheet.
- Construction and Durability: Materials are emphasised for strength and longevity. Jacks are commonly made from high-grade, hardened, and tempered alloy steel. Exposed surfaces are often hard chrome-plated for corrosion resistance. Designs are tested to meet ASME standards, and components like Grade 8 hardware are used for durability.
Design Features and Safety Mechanisms
The sources highlight several design features aimed at enhancing performance, versatility, and safety.
- Double-Acting Mechanism: This allows for powered push and pull cycles, offering positive control and speed in applications requiring extra strength and reliability. It interfaces well with automated operations.
- Counterbalance Valves: Integrated counterbalance valves act as hydraulic locks, preventing jack drift during transit and ensuring stability in both extended and retracted positions.
- Flow Dividers: These components are included in dual-jack kits to ensure both jacks operate in unison. They automatically redirect hydraulic fluid to the slower jack, balancing pressure and lift height for even lifting.
- Mounting Options: Trailer jacks are available in "Weld On" or "Bolt On" configurations, providing flexibility for different installation requirements. Industrial cylinders feature base mounting holes for easy fixture mounting.
- Optional Accessories: For enhanced versatility, some models offer optional mounting holes, collar threads, and tilting saddles. Hollow-type cylinders are also available, which can be used for tensioning wires, strands, bolts, or rods, or as standard cylinders when used with a head cap.
Applications and Use Cases
The described products are suited for a range of demanding applications, primarily in commercial, industrial, and heavy-duty towing contexts.
- Trailer Maintenance and Construction: Double-acting hydraulic trailer jack kits are explicitly designed for lifting heavy-duty trailers, including livestock, horse, car, cargo, dump, and flatbed gooseneck trailers. They facilitate building new trailers or replacing existing jacks, offering an easy setup and push-button operation.
- Heavy Industry and Construction: BEMCO JACKS' plain ram hydraulic jacks are built for superior strength in heavy lifting applications across these sectors. The double-acting cylinders from Gilmore & Kramer are suitable for applications requiring powered push and pull cycles, such as material handling.
- General Heavy Lifting: With capacities spanning from 12,000 lbs to 500 tons, these systems can handle a wide array of heavy equipment and loads, provided they are operated at 80% of their rated capacity for optimal safety, as recommended in one source.
Sourcing, Availability, and Commercial Terms
The provided materials offer insight into how these products are marketed and sold, though they do not mention free samples, trials, or promotional offers.
- Retail Channels: Products are available through manufacturer websites (e.g., Primary Mover, BEMCO JACKS, Gilmore & Kramer), online retailers like Amazon, and specialist trailer parts suppliers (e.g., Johnson Trailer Parts).
- Shipping and Logistics: Shipping policies vary. One source offers free shipping within the Lower 48 US states, noting that remote locations may incur an additional fee. Another emphasises same-day fulfilment from a warehouse, avoiding drop-shipping. Shipping weight for a complete 24K kit is listed as 225 lbs.
- Pricing and Offers: The Amazon listing for a Primary Mover kit notes "No featured offers available," indicating that the platform may not be displaying current promotions for that item at the time of the data snapshot. The product is sold under specific OEM part numbers (e.g., PFJ-2-MB-K, 12K-DBLTJ) and has a defined UPC.
- Customer Support: Manufacturers encourage potential buyers to contact them for expert guidance on selecting the right jack for specific needs, with one providing a phone number (602) 292-9690 and another suggesting LinkedIn for further information.
Conclusion
The source materials provide a comprehensive technical and commercial overview of double-acting hydraulic jacks and related systems. These products are characterised by high lifting capacities, robust construction from alloy steel, and safety features such as pressure relief valves and counterbalance mechanisms. They are primarily designed for industrial, construction, and heavy-duty towing applications, with specific kits tailored for trailer lifting. The information is sourced from manufacturer and retailer websites, which are considered reliable for product specifications and commercial terms. However, the provided data does not include any information regarding free samples, promotional offers, no-cost trials, or consumer-oriented mail-in programmes for these or similar products. Consumers seeking such offers would need to consult manufacturer websites or deal-finding platforms for potential promotions, as none are documented in the current source material.