Press Protective Sleeves

[Randy]

Safety can't be stressed enough when it comes to operating a hydraulic forging press. From cylinders, to fittings, to hoses, to operation. As far as hoses go, I highly recommend getting protective sleeves for all of your high pressure hoses. They run from around $3 per foot for the type that slide over to around $10 per foot for the kind that velcrow on over existing hoses. They are made in nylon, kevlar and other materials. Check with your local supplier/hydraulic shop so you can talk to someone to recommend what will work best in your situation. I attached mine with zip ties. What the sleeves do is protect the hoses from rubbing and brief contact with something hot. Due to this it helps the life of the hoses. Plus if a hose would develope a pin hole leak it will be contained in the sleeve and not spraying you or becoming a flame thrower. At that pressure they say that fine spray could cut off a finger, blind you or... Plus working with hot metal around gas or coal forges it wouldn't take much to ignite the spray. Well worth the minimal investment. Also worth looking into the non flamable hydraulic fluids.

[Daniel.85]

Thanks! I was planning on doing some type of protective covering when I start building the press, those look simpler than what I was thinking.

[ptree]

Non-flammable hydraulic fluid? you mean pure water right?
The fluids used that are "less Flammable" ,the actual name are usually Ethylene glycol based and are used in a mix with water. The mix ratio must be maintained since the water will evaporate when the system is operating and the fluid heats up. The Ethylene Glycol does not evaporate and when at the right concentration and below of water the Ethylene Glycol is actually rated as Flammable unlike straight hydraulic oil which is Combustible.

There were some aviation hydraulic fluids that were popular in the 50-60's like Pydaul and Skydral. Both expensive, and very hard on seals that are not exactly matched to the fluid.

Having worked for much of my career with hydraulics in industrial forges, I will say that the less flammable Ethylene Glycol are pretty good choices if you are willing to maintain the mix ratio, using a hand held refractometer. It has lower viscosity and is totally hard on urathane seals, but fairly easy on nitrile seals.

I would offer that designing the system for safety is your best defense. Use hard tube or pipe for your main runs. Sleeve your hoses, and don't run hoses across the floor where hot stuff can fall and rest against the fluid conductor. Place the hydrailics behind a sheet metal barrier if possible, or even on the other side of the shop wall with only the pressure and the return lines inside the hot work area.
A pump kill switch at the press as well as one on the way out of the area are cheap insurance as well.

[Daniel.85]

Thanks for the info ptree. I have definitely been planning for safety with the hydraulics, hard tube, sheet metal barriers and the kill switch(I also have kill switch for my whole shop). I would like to have the hydraulics(and an air compressor) behind a wall even for just the sound barrier, but that wouldn't work for me. I was planning on building a sound dampening box to put over it, like the ones for generators, that would also keep it protected. I'm using induction as well so no open fires should be safer.

[Randy]

ptree, is there still the balance problem with small units like we're using? Guess it should be stated to not mix the two types of fluid. Also do the fire resistant fluids have any issues, too?

Thanks for your input.

[ptree]

ANY water-glycol mixtures, made by many companies are subject to the water evaporating. You should obtain and read the MSDS and Tech data sheet for a fluid to understand the requirements for that fluid. There may be Polygycol/water fluids on the market now, and if so I have not used those.
The fire insurance indusrtry calls the water Ethylene Gycol fluids Less Flammable:)

I don't know if the older MIL-SPEC fluids like Pydroil and Skydroil etc are even still available.
Citgo had a water Ethylene Gycol that was widely available and the additive package allowed it to work reasonably well with units that had been operated on Petreoluim oils with a drain only.
Once the fluids are past 50% water in the mix then there are yet other problems like Pump Cavatation at the inlet if the suction head is too high. Cavatation will destry a pump quick, and sheds metal into the system!
Many of the High Water Content Fluids (HWCF) that I worked with in the late 70's were 95% water but had to have either a flooded suction or a centrifugal pump to feed the hydraulic pump suction.
Flooded suction is as easy as the tank above the pump inlet. True HWCF pumps were designed that were much better at operating with a very low vapor pressure like 95% water. These did eat the Urathane seals and wipers out of components as well as tending to rust the tank roofs if the 5% oil was not maintained.

OIL is easy on the machines but dangerous in a forge. Water is fire proof, but eats machines, and is almost never used pure. You pretty much need a middle ground, for fire safety and machine life, but the compromise must be maintained.