Unplugging a pipe and pump with hot liquid

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Oregon Occupational Safety and Health Division Division 2 - (iv) Low-melting materials. When low-melting point materials such as aluminum and brass or materials that soften on fire exposure such as plastics, or nonductile materials such as cast iron, are necessary, special consideration shall be given to their behavior on fire exposure. If such materials are used in above ground piping systems or inside buildings, they shall be suitably protected against fire exposure or so located that any spill resulting from the failure of these materials could not unduly expose persons, important buildings or structures or can be readily controlled by remote valves. - (3) Pipe joints. Joints shall be made liquid-tight. Welded or screwed joints or approved connectors shall be used. Threaded joints and connections shall be made up tight with a suitable lubricant or piping compound. Pipe joints dependent upon the friction characteristics of combustible materials for mechanical continuity of piping shall not be used inside buildings. They may be used outside of buildings above or below ground. If used above ground, the piping shall either be secured to prevent disengagement at the fitting or the piping system shall be so designed that any spill resulting from such disengagement could not unduly expose persons, important buildings or structures, and could be readily controlled by remote valves. - (4) Supports. Piping systems shall be substantially supported and protected against physical damage and excessive stresses arising from settlement, vibration, expansion, or contraction. - (5) Protection against corrosion. All piping for flammable liquids, both above ground and underground, where subject to external corrosion, shall be painted or otherwise protected. - (6) Valves. Piping systems shall contain a sufficient number of valves to operate the system properly and to protect the plant. Piping systems in connection with pumps shall contain a sufficient number of valves to control pr…

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When you perform maintenance above ground level, use appropriate devices such as ladders or man lift machines. If equipped, use the machine anchorage points and use approved fall arrest harnesses and lanyards. ## Pressurized Air and Water Pressurized air and/or water can cause debris and/or hot water to be blown out. The debris and/or hot water could result in personal injury. When pressurized air and/or pressurized water is used for cleaning, wear protective clothing, protective shoes, and eye protection. Eye protection includes goggles or a protective face shield. The maximum air pressure for cleaning purposes must be reduced to 205 kPa (30 psi) when the nozzle is deadheaded and the nozzle is used with an effective chip deflector and personal protective equipment. The maximum water pressure for cleaning purposes must be below 275 kPa (40 psi). Avoid direct spraying of water on electrical connectors, connections, and components. When using air for cleaning, allow the machine to cool to reduce the possibility of fine debris igniting when redeposited on hot surfaces. ## Trapped Pressure Pressure can be trapped in a hydraulic system. Releasing trapped pressure can cause sudden machine movement or attachment movement. Use caution if you disconnect hydraulic lines or fittings. High-pressure oil that is released can cause a hose to whip. High-pressure oil that is released can cause oil to spray. Fluid penetration can cause serious injury and possible death. ## Fluid Penetration Pressure can be trapped in the hydraulic circuit long after the machine has been stopped. The pressure can cause hydraulic fluid or items such as pipe plugs to escape rapidly if the pressure is not relieved correctly. Do not remove any hydraulic components or parts until pressure has been relieved or personal injury may occur. Do not disassemble any hydraulic components or parts until pressure has been relieved or personal injury may occur. Refer to the Service Manual for any procedures …

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- (i) piping from the discharge side of the pressure relief device is continuously sloped to drain fluids and protect fluids from freezing. 776 (2) An employer must ensure that pipes and fittings installed and maintained at a work site meet the requirements of ASME B1.20.1-2013 (R2018), Pipe Threads, General Purpose (Inch) , for threaded connections. 776 (3) An employer must ensure that a mud gun used for jetting is secured against unintended movement. 776 (4) If a downhole positive displacement pump is used in a wellhead, an employer must ensure that the pump is prevented from creating pressures that exceed the pressure rating of the piping and pumping system. 776 (5) An employer must ensure that no valve is closed on the discharge line of a positive displacement pump while the pump is in operation. 776 (6) A worker must not close a valve on a discharge line of a positive displacement pump while the pump is in operation. AR 191/2021 s776;242/2022;202/2024 ## Controlling pressure hazards 776.1 (1) An employer must ensure that a piping system is - (a) designed, installed and maintained to withstand the maximum anticipated pressures, - (b) tested when it is initially installed and after any modifications to it to verify that it can withstand the maximum anticipated pressures, and - (c) operated within maximum pressures referred to in clause (a). ## 776.1 (2) An employer must ensure that - (a) any hazardous energy that may be released from pressurized equipment is directed away from workers, or - (b) there is shielding, restraints or other controls in place to protect workers. 776.1 (3) If pressure in a piping system at the work site may exceed 3000 kilopascals, an employer must ensure that - (a) the piping system connections are welded, flanged or have hammer unions, or - (b) if the only connection on the wellhead is a threaded connection that is integral to the wellhead, the component parts of that threaded connection are compatible with each other. 776…