Responsibilities (W.I.T. Development)

W.I.T. Development and Contracting

This program outlines the minimum requirements that will be met by W.I.T. Development and Contracting,Ine when performing high-pressure water cleaning (HPWC).




  • Provide proper equipment and procedures

Provide safety training for all operators of HP Water systems

  • Perform periodic inspections and audits


  • Oversee all operations involving use of high pressure water
  • Ensure equipment is safe prior to use
  • Allow only qualified employees to operate equipment
  • Ensure areas are safe for passers by
  • Ensure all equipment meets the requirements of this program
  • Provide employees with on-job training
  • Maintain records of maintenance and training
  • Provide safety controls at all work sites


High-pressure water cleaning: The use of high-pressure water, with or without the addition of other liquids or solid particles, to remove unwanted matter from various surfaces.

High-pressure water cleaning systems: Water delivery systems, which have nozzles or other openings whose function is to increase the speed of liquids. Solid particles or additional chemicals may also be introduced, but the exit in all cases will be a free stream. The system includes pumps (pressure reducing devices) and the hoses, lances, nozzles, valves and safety devices as well as any heating elements or injection systems attached thereto.

High-pressure water cutting: The use of high-pressure water, with or without the addition of other liquids or solid particles, to penetrate into surfaces of a material for the purpose of cutting that material.

Dump valve: A device that immediately shuts down the high-pressure water stream if the operator loses control.


High-pressure water cleaning is normally performed using jet streams that can have a velocity greater than that of a 45-caliber bullet, and do as much damage. Therefore, extreme caution and strict compliance with procedures must be used to prevent the jet stream from striking the operator, other employees or delicate equipment. No portion of the body must ever be placed in front of the water jet. These jets of water can easily puncture and tear the skin or penetrate deeper causing infection or serious internal damage. Horseplay with such equipment is strictly forbidden. Violators will be disciplined and subject to immediate termination.



Personnel performing high-pressure water cleaning that are exposed to water spray or reflected material will wear a raincoat, rain pants, safety glasses, hardhat with face shield, rubber boots and gloves. Hearing protection will also be worn. These do NOT provide protection from the jet but do protect against hazards encountered while performing the work.

The following identifies at a minimum the personal protective equipment that will be issued to employees performing high-pressure water cleaning outside of the required hardhat and safety glasses with side shields:

Face shields — Clear shield nine inches deep by fifteen and one-half inches wide by 0.60 thick (ANSI Z87.1-1979 or equivalent).

Rain Suit — Standard vinyl rain suit

Gloves — Made of Neoprene, rubber and PVC with rough wet grip finish.

Rubber steel-toed boots — Knee length with ribbed steel shanks and heavy tread soles for nonslip traction (ANSI Z41.1-1967 or equivalent).

Metatarsal Guards — Designed to be worn with lace-type steel toe boots.

When cleaning equipment which could possible be contaminated with hazardous chemicals, appropriate additional protection specified by the project management/safety will be worn by the operator as well as other employees who may be affected.

When tube lancing or "shotgunning", boots provided with steel toecaps and metatarsal protection will be worn.



The High-Pressure Water Cleaning Job Qualification form (see focus section) must be completed prior to performing any high-pressure water cleaning to deteirmine if there are alternate methods for performing the task that are less hazardous.

The HPWC system will be depressurized when: Not in use.

  • Unauthorized or inadequately protected personnel enter the barricaded area.
  • Replacement or repairs are made to the system.

Recommended practices are violated.

Any incident, near miss or abnormal occurrence will be immediately reported to the responsible supervisor and an investigation conducted.

A cleaning crew will be composed of at least two operators. Each crew member will be in view of another crew member at all times.

Operators will not operate equipment for more than eight (8) consecutive hours in any sixteen (16) hour period. The team members should. rotate their duties during the job to minimize fatigue to the operator holding the tools.

The equipment operator nearest the high-pressure nozzle must always have a means of immediately reducing pressure or interrupting the flow to the nozzle.

When the hose drop exceeds ten (10) feet, the hose will be securely tied off to a rigid support with a fiber rope to limit the pull due to hose weight. Bend radius limits (as identified by the manufacturer) must be maintained.

At least one control valve or switch will control each high-pressure tool. An employee will operate only one high-pressure lance or shotgun at one time.

The area around the job, pump and hoses will be barricaded a minimum of fifteen (15) feet and signs stating "D.AiNGER IIIGH-PRESSURE WATER CLEANING" must be placed at the perimeters. Barricades may be of rope, tape, barrels, etc. as long as they give an effective warning and are highly visible.

If the job is above ground level, barricades may be required below. Warning signs should be placed along those portions of the high-pressure water hose, which are outside the barricades.

High-pressure cleaning hose will be positioned and handled to minimize bends and turns. Sharp bends and turns can result in hose failure.

High-pressure hose connections will have safety cables, chains or the equivalent bridging at each joint.

High-pressure water cleaning equipment must be designed and maintained to achieve a minimum safety factor of three to one (3:1) against maximum allowable working pressure.

The operator responsible for the job will fill out the High-Pressure Water Cleaning Equipment Checklist form before starting each job.

The pressure must be removed from the system before tightening or loosening fittings.

When the hose is pressurized, personnel must not handle the hose within one foot of the hose-to­hose connections.



Reactive back thrust forces from the high-pressure water jets physically stress the operator and affects operator control. Sound footing conditions must be established and maintained during cleaning.

Back thrust forces results from water leaving the nozzle at a high velocity. During manual shotgun cleaning operations, back thrust can be calculated from the equation below.

Back Thrust (lb) — 0.052 Q I P

Where: Q-Flow Rate in U.S. gallons/minute P — Jet Pressure Measured in PSI

For determining GPM, use the equation: Q-{29.9(K) D2) (tP)}

Where K — 0.09 constant

Operators of the shotgun-type equipment will not be required to withstand a back thrust of more than one-third (1/3) of their body weight.

If the area to be blasted is in a cozened space or the operator must climb to an elevated position such as on a ladder or scaffolding, it is required that a safety harness be used. Railings or other protection should be provided.

DO wear protective clothing.
DO stop unit to change nozzle, hose assemblies and other parts.
DO stop unit in case of a leak.
DO wear a safety harness when in an elevated position.
DO use only the manufacturer's recommended chemicals.
DO use sediment — free water.

DON'T tie gun lever or trigger down.
DON'T start the unit with the gun engaged.
DON'T aim the gun at people, light unsecured objects or other potential hazards.
DON'T engage gun unless it is properly connected and held.
DON'T lay the gun in mud, dirt or sand.



An automatic relief device will be installed on the high-pressure side of the pump set to relieve at not higher than the maximum allowable working pressure of the lowest rated component in the high-pressure system.(Rupture Disc Provided By Lion Elastomers)

Prior to starting the job, a visual inspection of the high-pressure components (including rupture disk pressure rating) should be performed. Hose with exposed or damaged wire braid will be removed from high-pressure service. The assembled high-pressure water cleaning components will be SLOWLY pressurized to the maximum operating pressure to verify integrity of the system.

A hose inspection and testing program (per manufacturer's guidelines) will be conducted at least quarterly. The inspection test will be conducted at 1 '/2 times the maximum operating pressure and will be observed by supervision.

Hose failures usually occur near fittings due to bending stresses during use and handling. Pressurized hoses will NOT be handled within one foot of hose-to-hose connections. Hose-to­tool connections, which are in frequent contact with the operator, must be shielded by a shroud to protect the operator. These shrouds must have sufficient rigidity to resist bending to radius smaller than those recommended by the hose manufacturers.



The following items will be overhauled and inspected for proper functioning at the manufacturer's recommended intervals (All EQUIPMENT PROVIDED BY Lion Elastomers)

  • Pressure relief valve
  • Bursting discs (if used)
  • Pressure control valves Hand or foot operated dump control valve or dry shut-off valve
  • Dry shut-off valve or dump systems
  • Changeover valve



When maintaining or assembling high-pressure water cleaning systems, the correct size tool MUST be used. The use of adjustable tools having serrated gripping jaws (i.e. pipe wrenches), which can damage equipment, will NOT be used.

NOTE: Only manufacturer's parts may be used for repairs to equipment. Manufacturer's equipment will not be altered or modified under any circumstances. (all parts provided by Lion Elastomers)



Shot gunning is our preferred basic high-pressure water cleaning method. Different variations of
each method are available and increasing with new technology. Rotating nozzle assemblies,
rotating lances and orbital nozzles are some variations available at this time.

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