Engineering Projects/Igloo/Howard Community College/Fall2012/p1-502-lash/safety

Safety Warning
 *** SAFETY WARNING - Before attempting to operate the pressure washer or conduct this test, read the pressure washer manual in addition to this safety procedures page ***  

Potential Risks
Safety and health risks relating to high pressure hydraulic systems arise from several different causes and pose the possibility of several types of injury. P. D. Ayers of Colorado State University claims in his article, Hydraulic Systems Safety, "Three kinds of hazards exist: burns from the hot, high pressure spray of fluid; bruises, cuts or abrasions from flailing hydraulic lines; and injection of fluid into the skin. The Mine Safety and Health Administration, in Dangers of a Failed Hydraulic Hose reiterates these risks, and adds to them electric shock hazard and fire/explosion hazard if flammable hydraulic fluid enters the air at high temperature and pressure  The CleanForce 1800 pressure washer's manual echoes the concerns of fluid injection injuries, fire or explosion hazard if flammable liquids are sprayed, and the danger of electric shock, and adds that the pressure washer's output stream should never be directed at people or animals.  The Cleanforce 1800 manual additionally says that the pressure washer contains lead, which could pose a health hazard if proper precautions are not taken. Gates Corporation, in its internet article Hydraulic Hose Life Made Simple, says:


 * "Hoses, couplings, assembly equipment, and crimping tolerances vary from one manufacturer to another, and are not interchangeable. Gates says that if components are mixed, coupling retention could be adversely affected. Mixing components not only causes unnecessary downtime, but also, personal injury can result."

In the case of splicing the output hose of this pressure washer, we were unable to find the original manufacturer's specifications for the hose and hose end, and we were not able to use a hose end from the same manufacturer. Additionally, the Colliflower employee who crimped the ends on said that because he did not sell us the hose, he could not guarantee that the fitting would hold or would not leak. The purpose of this test is to establish whether or not the fitting, as it is crimped, will hold the full operating pressure of the pressure washer. Based on the Gates Corp. article, and for the other reasons outlined above, we need to be prepared for the splice fittings to fail.

The risk factors outlined thus far can be summarized as:


 * Fluid injection into the skin
 * burns from hot fluid contacting the surface of the skin
 * physical injuries due to to moving high pressure hoses
 * injuries from being in the path of the output stream
 * electric shock
 * fire/explosion from flammable liquids being sprayed at high pressure
 * lead contamination from lead integral to the pressure washer's construction
 * injuries caused by impact of flying hose ends or other parts in the event of joint failure

Of these, the following do not apply to this situation: (reasons given in parenthesis)


 * burns from hot fluid contacting the surface of the skin (pressurized fluid will be cold water and will thus not cause burns)
 * fire/explosion from flammable liquids being sprayed at high pressure (pressurized fluid will be cold water, which is not flammable)

This leaves the following risk factors for us to take steps to mitigate. Detailed mitigation procedures for each are explained in the next section.


 * Fluid injection into the skin
 * physical injuries due to to moving high pressure hoses
 * injuries from being in the path of the output stream
 * electric shock
 * lead contamination from lead integral to the pressure washer's construction
 * injuries caused by impact of flying hose ends or other parts in the event of joint failure

Fluid injection into the skin
The first line of defense to mitigate this risk will be to operate the test apparatus with a remote control console from a protected location. Locations considered thus far have included on the opposite side of the Plant Ops dumpster from the test set up, and around the corner from the water spigot outside the Clark Building exit door below SA 201.

The second line of defense will be to wear personal protective equipment, such as heavy clothing, gloves, and a face mask or goggles.

The third line of defense against this will be to utilize the standard practice, advised in the pressure washer's manual and several safety articles, of releasing hydraulic pressure before working on the system. We intend to accomplish this with a solenoid valve on the high pressure side capable of being operated from the remote control console.

If initial tests give positive results, we will check for pinhole leaks in the hose prior to beginning regular operation by using the procedure outlined by P.D. Ayers of Colorado State University.

physical injuries due to to moving high pressure hoses
Our first line of defense against this risk will be operating the apparatus from a remote, protected location, as described above.

Our second line of defense will be to tie the hoses with rope, at several different points, to sawhorses in order to restrain them in case of breakage or splice joint failure.

our third line of defense against this risk will be the personal protective equipment described above.

injuries from being in the path of the output stream
Our first line of defense will be to aim both output hose and pump port ad a solid backstop, such as a wall of the Clark building, so that the water is sprayed in a safe direction, even if the hose connection to the pump fails.

Our second line of defense will be operating the apparatus from a protected area.

Our third line of defense will be wearing personal protective equipment.

electric shock
To reduce this risk, ideally we would be able to power the apparatus from an outlet equipped with a Ground Fault Circuit Interrupter. If this proves impossible, we can include one in the remote control console so that the power to the test apparatus itself will be GFCI protected. Finally, we will be physically away from the test area, which would reduce the risk of contact with water from the test, which could reduce body resistance. There is also a GFCI built into the pressure washer, but it is not intended to be plugged into an extension cord.

lead contamination from lead integral to the pressure washer's construction
Our first line of defense will be to assemble the pressure washer as completely as possible prior to initiating the test.

Our second line of defense will be to wash our hands and arms immediately following the test.


 * might want to look for ways to reduce or prevent adverse environmental impacts

injuries caused by impact of flying hose ends or other parts in the event of joint failure
Our first line of defense will be to operate the apparatus from a remote, protected location, details of which process are described above.

Our second line of defense will be wearing personal protective equipment, such as heavy clothing, gloves, and goggles

Additionally, there is a pressure sensitive switch built into the pressure washer unit (called the "total stop system" by the manufacturer) which turns the motor off when the pressure reaches the maximum intended for the system.

We will also make every effort to obtain a gauge for the high pressure side so that we can monitor the pressure and cut power to the unit if it exceeds 1800 PSI. We plan to monitor the test with a camera and remote monitor; We might be able to put the pressure gauge in the view of the camera so we can monitor pressure remotely. If not, we will need to find a pressure transducer to allow us to send a signal to the remote operating console.

Finally, prior to working on the system, we will relieve the high pressure by remotely opening a solenoid valve.


 * Still need to work on this, especially protection of passers by and automobile traffic

 For details of equipment needed to perform the test in accordance with this plan, see the hose test page