Enerpac’s no-tears way to peel away problems of onion jack stressing

One of the challenges to the popular method of using an onion jack to stress steel strand cables in concrete structures is ensuring safe reliable hydraulic power where mains electricity is not always available.

Enerpac XC cordless pumps provide a clean, quiet go-anywhere source of power for the onion-jack method, which involves applying hydraulic force to the clamped end of the braided steel stressing strands, which forms into an onion shape that can then be fixed and concreted into place within the concrete structure to form an anchoring point to stress from.

These powerful 700 bar (10,000psi) cordless hydraulic pumps offer the performance capabilities of an electric or pneumatic powered pump with the convenient portability of a hand pump, says Enerpac Australia and New Zealand National Sales Manager Mr Darryl Lange. Designed to satisfy the need for a long-lasting pump that can be used in hard-to-access and remote areas, XCSeries cordless pumps are constructed of lightweight materials, equipped with a powerful, one-half horsepower motor and feature 28-volt, Lithium-Ion battery technology to deliver the speed, power and longevity of a corded pump.

“In addition to powering onion jacks, these versatile pumps can also be used in and around inaccessible and remote sites to power a host of tools widely used in construction, infrastructure, building, mining, energy, industrial plant and vehicle maintenance tasks. The lightweight XC pump comes complete with a carry strap for increased mobility on site,” said Mr Lange.

The onion jack process is common to multi-story or slab construction where access is inhibited by beams or other obstructions. In such cases, worksite personnel cannot use stressing cables’ standard live end and dead ends.

The Enerpac onion jacking method can also be used where a strand blow-out has occurred and needs rework to the strand, says Mr Lange.

With its bladder reservoir, Enerpac’s cordless pumps eliminate venting and offer leak-free operation in any orientation. Plus, the overall body, handle and trigger have been ergonomically engineered to maximise ease-of-use and portability. XC-Series cordless pumps deliver oil flow of two litres per minute at its low-pressure setting and .25 litres per minute when operating at full pressure, up to 700bar (10,000 psi). Additionally, the lithium-ion technology ensures XC-Series pumps provide end users with the battery runtime necessary to accommodate demanding application requirements. Enerpac’s XC-Series promotes operator safety by removing trip hazards associated with traditional powered pumps, and a trigger lock-off mechanism that protects against unintended operation during transport. “With our in-depth understanding of industry demands and the challenges plaguing portable pump technology, we designed the XC-Series to be a durable solution versatile enough to satisfy our customers’ performance requirements,” said Mr Lange. “The XC-Series features a two-litre reservoir model, making this cordless pump the ideal solution for operating small to medium tools and cylinders.” The XC series portable pump complements the broader Enerpac range of pumping technologies used and backed with comprehensive service throughout Australasia, ranging from hand types to powerful, energy-saving electric and fast-acting pneumatic types. The ranges include rugged workhorses such as the ZU448REA300 double-acting pump can be coupled with compact and powerful Enerpac post-tensioning tools for mono strand construction applications common on building and infrastructure development sites. Enerpac features a versatile line of concrete pre-stressing and post-tensioning products, along with an extensive range of associated hydraulic pumps and accessories, all from a single source.