Hercules Jack FAQs

Q. Does the Jack come calibrated?
A. No jacks ever ship to a customer calibrated. Unfortunately, the shipping companies are not the most gentle people and more times than not your jack would not be calibrated by the time it got to you. Many state D.O.T.’s and PCI require the jack to be calibrated once it arrives at your plant.

Q. Can I calibrate my own jack?
A. Yes, you can provided some conditions are met. First, a Calibration Loadcell calibrated through NIST, National Institute of Standards. Second, you should have a knowledgeable person (PCI requires a P.E.) who is familiar with the operation of both the loadcell and the jack, as well as an understanding of the calibration procedure.

Q. Can I hook a different brand of ram up to my Hercules pump unit?
A. No. Our system works on 3000 psi operating pressure and our gauges are set up for our specific ram piston area, Model “B” 17.23 sq. in., Model “C” 22.8254 sq. in. So, it is very important to only use Hercules rams with Hercules pumps.

Q. Can I operate my Model “B” ram off my Model “C” pump unit or vice versa?
A. No. Due to the different ram piston area, you must use a Model “B” ram with a Model “B” pump and a Model “C” ram with a Model “C” pump.

Q. How often do I need to change the oil and filter?
A. If your jack is used a lot, we recommend filter changes quarterly and oil annually. Should the oil become contaminated, e.g., water or dirt, stop stressing and change the oil and filter. Depending on the severity of the contamination, repeating these steps may be necessary. Be sure to check your oil level every morning. Recommended oil can be found in the manual.

Q. Why won’t my initial analog gauge zero out?
A. As long as the pump is running it is creating residual pressure and the analog gauge is detecting it.  The digital gauge’s programing will allow it to zero out.

Q. Can I hook my ram up to a swing arm or gantry?
A. Due to the weight of the rams, many prestress operations choose to hoist the ram in any number of ways. Make sure the lifting aid enables the ram to stress straight and true with the direction of the strand.

Q. Why are your Hercules rams so heavy?
A. We have to make them tough . They are going in a prestress yard! Do some math. Think of the number of pulls each year and the loading of each pull. Now multiply that by 10 or 20 years and that is a lot of loading cycles. In order for the rams to last that long, they have to be manufactured tough, thick and, unfortunately, heavy.

Q. Why do I need to use the ease-off function when stressing?
A. You need to use the ease-off function to prevent shock loading the strand and strand chucks. The ease-off function allows the hydraulic pressure (load) to release gradually allowing the strand chuck to lock on to the strand in a slow and controlled manner. Bypassing the ease-off function will cause the pressure to release instantly, transferring the load in the strand chuck. Better known as shock loading, this is bad for the strand and the strand chucks. The gauges in your jack can also be jarred out of calibration.

Q. Why do I need the strand safety latch at the end of the ram?
A. The strand safety latch not only keeps the strand from flying out, it also helps keep the strand centered in the ram during stressing.

Q. Can I disable the horn and light?
A. We do not recommend that you disable the horn and light. They are there for a reason. Prestressing is inherently dangerous and the horn and light is a good way to warn your employees to get away from the stressing area. Organizations such as PCI require you have such warning devices.

Q. Can I install quick disconnects on my hydraulic hoses?
A. We do not recommend this. Hoses with quick disconnects can be dropped or drug around on the ground picking up all kinds of contamination. Next the hoses get plugged back in and so does the debris. Just a little bit of contamination in the system can cause all kinds of trouble with a hydraulic system.

Q. Where can I get parts for my Hercules jack?
A. You can buy parts for the Hercules jack through us. Many of the parts, such as Sun cartridges, motors and hydraulic pumps, can be found locally.