How to size hydraulic breaker

When sizing the breaker to the machine, two key points should be given careful consideration:

l Machine operating weight

l Hydraulic system capabilities

With the correct carrier weight, RockAge offers hydraulic breakers that are designed to break any material that the machine can handle. Sizing the breaker by carrier hydraulics gives the operator a carrier/breaker combination designed to optimize the system efficiency, thereby reducing heat generation and eliminating power loss.

The following steps will result in a well-matched installation. This manual will not cover all types of applications, so for assistance in any unusual situations please contact your RockAgerepresentative.

Based on Carrier Weight

By using the Carrier Sizing Chart below, you can narrow your hammer choice. Normally breaker production rate is the most crucial factor when trying to choose a breaker size. It is of great benefit to do some research and understand your hydraulic system capabilities and the material size and hardness before determining an expected production rate. This rate will also be affected by breaking conditions and the operator.

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Based on the Type of Work

The Production Rate is the next important factor to consider in sizing the breaker. Most situations call for the largest breaker that your carrier could handle. The largest breaker is therefore the one to choose. The lifting capacity of your machine is then the limiting factor. The carrier must be able to safely handle the breaker at any distance out from the machine where you might be working.

Small Breakers

Smaller sized breakers up to 1,000 ft·lb class (1350 joule) are typically used in concrete and other light duty work.

Medium Breakers

Medium sized breakers 1,500-4,000 ft·lb class (2000-5400 joule) are used in both concrete and rock applications with limitations on the size and amount of material to be broken.

Large Breakers

Larger breakers greater than the 4,000 ft·lb class (5400 joule) are typically used in hard rock, high production applications.

Breaking Oversize

When breaking oversize material, the breaker is expected to break the material down quickly into multiple pieces. This is optimum production. If the operator has to re-position the breaker towards the edge of the rock and gradually downsize the material, the production rate slows down. To assess which breaker will effectively handle this application, the size and hardness of the material must be known.

For example, if a 4 cubic yard piece of hard rock (20,000 psi or greater) needs to be broken in half, a 7,500 ft·lb or larger breaker is required. If a 2 cubic yard piece of limestone (20,000 psi or less) needs to be broken in half, a 3,000-5,000 ft·lb breaker is required.

Trenching

When trenching, the breaker is expected to fracture a solid mass of rock into manageable pieces. The size of the material could be hundreds of cubic yards, and the energy will be quickly absorbed. This is why it is recommended to work from a bench so the rock has somewhere to break out.

When trenching in limestone or medium hard rock, use a 3,000 -5,000 ft·lb breaker. When working in hard material use a 7,500 -10,000 ft·lb breaker.

Breaking Concrete

When breaking Concrete, the breaker is expected to penetrate the material, allowing it to crack and shake loose from the reinforcing steel. High frequency breakers tend to provide better performance in this application. It is not the energy per blow, but the fast blow rate that destroys the concrete`s structural integrity.

On concrete walls, footings and floors use a 750-1,500 ft·lb breaker.

With larger projects consisting of large footings greater than 4 cubic yards, use a 2,000-5,000 ft·lb breaker. The high production demand of bridge and building demolition requires a 7,500-10,000 ft·lb breaker.