1. PURPOSE

This procedure describes the precautions required to protect personnel from the potential exposure to hazards associated with high pressure water cleaning (hydro blasting) operations.

2. SCOPE

This procedure applies to all types of hydro blasting operations within AMINAT COMPANY.

3. DEFINITIONS

3.1 HYDROBLASTING (HIGH PRESSURE WATER CLEANING)

The use of water in excess of 1725 kPa (250 psi) to clean unwanted accumulations of residues that adhere to equipment surfaces.

3.2 DEAD-MAN VALVE (FALL SAFE VALVE)

A manually operated fail safe valve which requires a consistent pressure by the lance operator to activate the water stream. It shall stop or divert the water stream if the handle is released.

3.3 LANCE

A rigid metal tube which is used between nozzle and the end of the hose.

3.4 NOZZLE

A device at the end of the hydro blasting system to restrict the flow so that the pump pressure can build up and deliver the decide water velocity.

3.5 RODDING

A hydro blasting operation where a lance and nozzle combination is inserted into and retracted from the interior of pipe or tube.

3.6 MOLEING

A hydro blasting operation where a hose, lance and nozzle combination feeds itself through a pipe by means of jets from the side or back of the nozzle.

3.7 SHOTGUNNING

A hydro blasting operation where a lance and nozzle combination can be directed in virtually all planes of operations.

4. PROCEDURE

4.1 GENERAL REQUIREMENTS

4.1.1 As a minimum, the hydro blasting equipment system shall consist of the following: 4.1.1.1 A water pump with relief system that is set so that the maximumAllowable working pressure is maintained in order to protect the weakest component.

4.1.1.2 A pressure gauge calibrated to the range of 2,000 kPa (290 psi) orgreater that is visible to the lance operator while hydro blasting.

4.1.1.3 The water system shall be equipped with a filter/strainer capable of removing particles larger in size than the smallest orifice in the nozzle.

4.1.1.4 The nozzle lance hose system shall have a minimum safety factor Of 2.5 based upon yield strength of the martials and the burst pressure rating of the hose.

4.1.1.5 The system shall have a dead-man valve which, when released, shall drop the system pressure to a safe level of 1380 kPa (200psi) within one second. The actuating device shall be protected to prevent inadvertent operation.

4.1.1.6 Electrical controls shall be kept to a minimum. Electrical dump system handled by personnel shall not exceed 12 volts and shall be fail safe.

4.1.2 A hazardous work permit is required for the use of hydro blasting equipment, which shall be used by the area/equipment owner after a thorough inspection of the equipment based on the attach check list (SF-34-A-01)

4.1.3 Only qualified personnel shall be allowed to operate the hydro blasting machine.

4.1.4 Before starting a job and at the beginning of each shift, the conductor and operation shall check out the condition of the hydro blasting equipment, including its accessories. The shall also examine the equipment to be cleaned to see if there is any potential hazard from debris, corrosive or toxic chemicals, flammable liquids or vapors, etc.

4.1.5 Barries and shields shall be installed to prevent un authorized personnel from entering the hydro blasting area (within 4.5m of the hydro blasting equipment). If the job is above ground level, warning signs also shall be displayed.

4.1.6 Consideration shall be given to the toxicity and disposal of material remove during cleaning operations. Special facilities may be required to collect debris wash water. Such requirement shall be discussed with the environmental engineer during job planning.

4.1.7 Adequate personnel protective equipment, such as hard hat with mounted chemical goggle and face visor, P.V.C. suit, safety rubber boots with non skid soles, impervious gloves, etc., shall be worn at all times as a minimum standard while hydro blasting. When tube lancing or shot gunning, boots provided with metatarsal (top of the foot and over the ankle metal guard) protection shall be warned.

4.1.8 High pressure hose shall not have kinks, cuts or chipping on outer rubber. Hose shall have pressure rating stenciled on its couplings. High pressure hoses shall be tested once every year. Records of tests shall be maintained.

4.1.9 Rubber hose and particularly its fittings shall be visually checked for any damage before each use.

4.1.10 Lance nozzle shall be designed to prevent release from support by impact. Support from the lance to vessel shall be designed so that falling scale is deflected from the support.

4.1.11 Lance shall not have any dents, cuts ot twists and shall be inspected visually before each use.

4.1.12 All safety (hand and foot operated) and other actuators and safety valves on high pressure side shall be tested once every year or after each pop-up or repair. Records of tests shall be maintained.

4.1.13 The mode of pressure regulating knob, to increase or decrease the pressure, shall be indicated by arrow heads.

4.1.14 The Contract Administrator shall make sure that the contractor technicians are trained in all facets of the hydro blasting process and that all necessary training records are available. This shall include:

4.1.14.1 Cutting action of high pressure water and correct selection of nozzles and water pressure.

4.1.14.2 Personnel protective equipment requirements.

4.1.14.3 Inspecting hydro blast unit.

4.1.14.4 Purpose of primary equipment.

4.1.14.5 System operation, including lance handling and emergency shutdown procedure and signals.

4.1.14.6 Safety devices and precautions.

4.1.14.7 Description of water supply factors, electrical hazards, electrical grounding and waste water control

4.1.15 A minimum of 2 men shall work as a unit with as few changes as possible inthe personnel involved. One man shall operate the lance while other monitors the engine, pump and maintains constant safety surveillance of the job area.

4.1.16 Hammering and tightening of unions or connections while under pressure shall not be done.

4.1.17 Adjacent equipments that require protection from the high pressure jet stream or water spray be guarded with appropriate material.

4.1.18 Multiple manual hydro blasting operations shall be separated by at least 6Meters or by an adequate physical barrier. Each operation shall be supplied by a separate pump. If multiple hydro blast activities are to be performed inside a confined space, Job Safety Analysis (JSA) shall be performed.

4.1.19 Equipment being cleaned shall not be hand held, but shall be secured to prevent movement.

4.1.20 The person operating closest to the nozzle shall have direct control of the dead-man valve (fail safe valve). The nozzle shall never be pointed at an individual. To make sure that the operator cannot point the lance towards himself, a minimum lance length of 1680 mm from butt to nozzle is required.

4.1.21 Appropriate precautions shall be taken before starting the hydro blasting machine. Its recommended to ensure the following before switching on the motor:

4.1.21.1 The automatic pressure relief valve is depressed into load position.

4.1.21.2 The foot operated valve is not pressed by the operators foot.

4.1.21.3 The trigger of spray pistol is not pulled.

4.1.21.4 The suction filter is not choked.

4.1.21.5 The water supply valve is open.

4.1.21.6 Hand held spray gun is fitted with trigger lock.

4.2 SHOTGUNNING

4.2.1 Steps shall be taken to minimize the effects of poor footing such as mud, slippery surfaces and wet deposits when shot gunning.

4.2.2 Hand-held shot gunning shall not be performed at 68,900 kPa (9993 psi) Nozzle pressure with a nozzle orifice larger than 1.6 mm due to excessive nozzle reaction forces. Deviation from this requirement shall be approved in advance by the Safety Engineer.

4.2.3 The 2 meter of high pressure hose closest to the shotgun shall be enclosed by a loose fitting-shroud to protect the operator in the event the hose develops a leak.

4.2.4 The use of double fail-safe valve for shot gunning is a standard equipment.

4.3 RODDING & MOLEING

4.3.1 When moleing or rodding, the lance or hose shall be clearly marked with paint or tape no closer than 600 mm from the nozzle to warn the operator to the nozzle location.

4.3.2 When moleing, the rigid section at the end of the hose shall have sufficient length to prevent the nozzle from turning around inside the pipe. The total length of the lance and nozzle shall be larger than the inside diameter of the pipe being cleaned.

4.3.3 When manuallyrodding equipment, the nozzle shall be inserted in the tube prior to pressurizing the system and removed from the tube after depressurizing. The lance shall be directed through a shield designed to protect the operator from water spray and to prevent the lance from being inadvertently withdrawn from the tube while still under pressure.

4.3.4 Bolts or other unsecured material shall not be used to mark holes in tube bundles, as they could become projectiles.

4.3.5 Hydroblast system hoses shall be handled to prevent kinking and excessive wear. High pressure hose connections shall have safety chains bridging each joint.

4.3.6 When hose drops exceed 3 meters, the hose shall be securely tied off to a rigid support to limit the pull due to hose weight.

5. REFERENCE

None

6. ATTACHEMENT

High Pressure Water Cleaning Check List.