Hydrotest safety procedure
Wow I get an off topic rate. Is there anywhere else fair? The OP probably's referring to hydrostatic test at construction site cold water line and waste water lines. I mean who would stand around testing high pressure tanks and measure the safe distance to observe it?
Isn't that silly don't you think? Why do people think that safety margins are calculated.
They are not calculated. They are empirically determined by the damage to flesh and property from when things go wrong. There isn't an equation for everything. It's bad manners. If you search precisely in internet, you can find an excel sheet prepared by someone to calculate the safe distance for both hydrostatic test and pneumatic test based on Lloyd's register T However, AI didn't ask for safe distance calculation to be followed during hydrotest.
Even both of us went inside the boiler to check for leaks during hydrotest. I am really sorry, at present I am bit busy and I am not in a position to describe the whole story due to time limitation. A person knowledgeable in boiler construction would have no problem understanding this.
They were in the fire side, not the water side. New Post. Comments Format:. Subscribe to Discussion :. CR4 allows you to "subscribe" to a discussion so that you can be notified of new comments to the discussion via email. Rating Vote:. Score 1 Score 2 Score 3 Score 4 Score 5. Add Vote. User-tagged by 1 user. Interested in this topic? By joining CR4 you can "subscribe" to this discussion and receive notification when new comments are added.
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Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Definition of Hydro Test: The hydro test is the test which is carry out by using water.
Pneumatic Test: A pressure or tightness test where a gas, generally nitrogen or air, is the test medium. Pressure piping system: means pipes, tubes, conduits, fittings, gaskets, bolting and other components that make up a system for the conveyance of an expansible fluid under pressure and may also control the flow of that fluid.
Pressure vessel: means a vessel used for containing, storing, distributing, processing or otherwise handling an expansible fluid under pressure. The main hazard during pressure testing is the unintentional release of stored energy. In the case of pneumatic testing, this can lead to a blast wave and missiles which can be deadly. However, in the case of hydro testing, the blast has little energy and it can be assume that all expansion energy goes into missile energy.
The release of stored energy can be due to:. Although pressure testing using a liquid as the pressurizing medium usually referred to as hydro-testing is not without risks, it is by far the safer method and should be used wherever practicable. Pressure testing using air or gas as the pressurizing medium usually referred to as pneumatic testing is potentially more dangerous because of the higher energy levels involved.
For example, the energy released during a total failure of pressure equipment containing compressed air at pressures frequently used in pressure testing is more than times the energy released by the same volume of water compressed to the same pressure.
Pneumatic Testing and Hydrostatic Testing for Pressure Vessels and Pipelines
Therefore, carrying out pneumatic testing in the refinery shall be highly discouraged. A disadvantage of hydro testing is the introduction of water in systems that must be water-free after the testing. Pneumatic testing may also be considered to test large diameter lines where temporary supports are not practical and also for refractory lined piping systems.
Brittle materials shall not be subjected to pneumatic pressure tests. Some commonly used brittle materials are glass, cast iron, and most high-strength alloys. The decision to apply a pneumatic test instead of a hydro test is restricted to the following situations:. The following section deals with the general precautions to be followed while doing pressure testing. The precautions are applicable for both hydro and pneumatic testing unless specifically mentioned, whether for hydro or pneumatic.
The first step to take before carrying out any pressure test both hydro and pneumatic is to perform a risk assessment of the activity. It helps to list the safety measures needed to carry out pressure testing.Log In. Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
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Promoting, selling, recruiting, coursework and thesis posting is forbidden. Students Click Here. Related Projects. Hello everyone, I will be working in setting up a hydrostatic testing following B Spool sizes will be up to NPS 8.
As of now, I do not know what will be the maximum pressure. The highest I've seen have been D Pressure Class. Well, I've been searching online for what are OSHA requirements in regards to barricading and safety measures but without any luck. Would anyone know where I can obtain this information? If you are using water for the hydrostatic test, there are no requirements because water is considered a non-compressible fluid for purposes of hydrostatic testing.
Most shops have an area cordoned off to conduct hydrostatic tests with temporary splash shields and floor drains to protect surrounding equipment in the event of a water leak. Could you share on any guidelines to follow on how much of an area must be closed for the test depending on the pressure level?
The other option is to use part of the production floor after completion of each spool to pressurize and test. I would use hazard tape on the shop floor to cordon off the area, depending on the size of the spool for a distance of 3 feet, for each test.
This should be described in your QA manual regarding test plans. Red Flag This Post Please let us know here why this post is inappropriate.
Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. This includes challenging trends on contractors and distributors like new refrigerants, growing automation, complex sensors and monitoring, green initiatives and a technician shortage. We look at these trends and outline actionable insights on how it all can be turned into a competitive advantage and business opportunity.A hydrostatic test is a pressure test in which the pipe or other component is pressurized to evaluate its integrity.
Pressure Testing Safety Procedure. For example, if the test pressure is determined to be psi, select a psi pressure gauge. The old guys in the workshop applied the pressure based on x1. If the hydrostatic test procedure didn't state the max test pressure allowed, then what would be the max limit? Hydrostatic testing is also required periodically to re-qualify these pressure vessels for continued service. During a hydrostatic test, a pressure vessel is placed inside a closed system, usually a test jacket filled with water, and a specified internal water pressure is applied to the container inside this closed system.
Type of Work. Section Hydrostatic Testing Procedure. Division 1, Latest Edition and Addenda. Procedure of this test is same that of normal hydrostatic test. The only exception is that the test vessel is checked for distortion or malfunctioning during the course of proof-pressure test.
Where systems require hydrostatic testing through static equipment, the test pressure shall be selected so as not to exceed vessel test pressure. Provide full face blanks and gaskets for CL connections. Cryogenic pressure vessels with Code Stamps are no different. Test pressure and holding time shall be as follows: a.
Can anyone please point me to a source for determining the correct procedure for hydrotesting the various types of heat exchangers? Uploaded by. Dalam melakukan Hydrotest, ada beberapa prosedur yang umum dilakukan antara lain ; 1. Personal Responsibilities QC Inspector a. Mempersiapkan semua peralatan seperti pressure gauge, temperature indicator dan pressure recorder. Hydrotest Method Statement 12th Mar Hydrotest Procedure.
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To prevent this from happening, all portable fire extinguishers are required to be inspected and pressure tested by a qualified individual using the proper equipment and facilities. Hydrostatic testing is the method used to pressure test an extinguisher's critical components cylinder, shell, hose assembly, etc. This section is intended to help you understand what you need to do to comply with OSHA's requirements for "Hydrostatic Testing".
First, the extinguisher valve is removed and the threads and interior of the cylinder are checked for corrosion, pitting, and any other abnormalities. A glass burette attached to the side of the steel chamber will read zero, indicating normal or zero pressure of the chamber water.
Water is then applied at high pressure to the interior of the extinguisher's cylinder. As the pressure increases, the cylinder will expand and push water from the steel chamber through a small hole and into the glass burette. After the pressure is released, the cylinder will contract and the water will move from the burette back to the steel chamber. Depending on the results, the tester will either pass or fail the cylinder.
The cylinder is normally considered unsafe and will fail if:. The hydrostatic test described above is called the water jacket type because the cylinder is enclosed and surrounded by water during the testing process. All compressed gas type cylinders CO 2dry chemical, etc. They must also have an expansion indicator that operates with an accuracy within one percent of the total expansion or. For all non-compressed gas type cylinders, you can use a manual or powered hydrostatic test pump as long as it meets the following requirements [ 29 CFR NOTE : Do not use air or gas pressure for hydrostatic testing because it compresses and expands many more times than water, which makes it very dangerous.
To ensure that your extinguisher will operate effectively and safely, you are required to have them hydrostatically tested:. It is illegal and dangerous to perform a hydrostatic test on any cylinder or shell without first doing a visual external and internal examination. If any component exhibits at least one of the following conditions, it must be removed from service immediately.
Hydrostatically test portable extinguishers at the intervals listed in Table L-1except under any of the following conditions:. Depending on the type s of extinguishers you have, they must be emptied and hydrostatically tested at the intervals specified in Table L Extinguisher shells, cylinders, or cartridges that fail a hydrostatic pressure test, or which are not fit for testing, shall be removed from service and the workplace.
NOTE : All hose assemblies must be hydrostatically tested at the same interval as the extinguisher if it is equipped with a shutoff nozzle at the discharge end. This information should also be securely fixed to each extinguisher, and provided upon request to the Assistant Secretary as evidence that the required hydrostatic testing of fire extinguishers has been performed at the time intervals shown in Table L These records must be kept until the extinguisher is hydrostatically re-tested at the time interval specified in Table L-1 or until the extinguisher is taken out of service, whichever comes first.
Nitrogen cylinders that comply with 49 CFR The Department of Labor does not endorse, takes no responsibility for, and exercises no control over the linked organization or its views, or contents, nor does it vouch for the accuracy or accessibility of the information contained on the destination server. The Department of Labor also cannot authorize the use of copyrighted materials contained in linked Web sites.
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The cylinder is normally considered unsafe and will fail if: The water level in the burette continues to rise while the specified pressure is applied. This could be due to a leak from the inside cylinder to the water in the steel chamber, or to a continual expansion of the walls of the cylinder, both of which would be a reasonable cause to fail the cylinder.
The cylinder stretched and with the pressure released does not return to its original size or close to itit would mean the metal of the cylinder is not resilient enough to be considered safe for use.A hydrostatic test is a way in which pressure vessels such as pipelinesplumbinggas cylindersboilers and fuel tanks can be tested for strength and leaks.
The test involves filling the vessel or pipe system with a liquid, usually water, which may be dyed to aid in visual leak detection, and pressurization of the vessel to the specified test pressure. Pressure tightness can be tested by shutting off the supply valve and observing whether there is a pressure loss. The location of a leak can be visually identified more easily if the water contains a colorant. Strength is usually tested by measuring permanent deformation of the container.
Hydrostatic testing is the most common method employed for testing pipes and pressure vessels. Using this test helps maintain safety standards and durability of a vessel over time. Newly manufactured pieces are initially qualified using the hydrostatic test. They are then re-qualified at regular intervals using the proof pressure test which is also called the modified hydrostatic test. Hydrostatic tests are conducted under the constraints of either the industry's or the customer's specifications, or may be required by law.
The vessel is filled with a nearly incompressible liquid — usually water or oil — pressurised to test pressure, and examined for leaks or permanent changes in shape. Red or fluorescent dyes may be added to the water to make leaks easier to see.
The test pressure is always considerably higher than the operating pressure to give a factor of safety. This factor of safety is typically Water is commonly used because it is cheap and easily available, and is usually harmless to the system to be tested.
Hydraulic fluids and oils may be specified where contamination with water could cause problems. These fluids are nearly incompressible, therefore requiring relatively little work to develop a high pressure, and is therefore also only able to release a small amount of energy in case of a failure - only a small volume will escape under high pressure if the container fails. Small pressure vessels are normally tested using a water jacket test. The vessel is visually examined for defects and then placed in a container filled with water, and in which the change in volume of the vessel can be measured, usually by monitoring the water level in a calibrated tube.
The vessel is then pressurised for a specified period, usually 30 or more seconds, and if specified, the expansion will be measured by reading off the amount of liquid that has been forced into the measuring tube by the volume increase of the pressurised vessel.
The vessel is then depressurised, and the permanent volume increase due to plastic deformation while under pressure is measured by comparing the final volume in the measuring tube with the volume before pressurisation. A leak will give a similar result to permanent set, but will be detectable by holding the volume in the pressurised vessel by closing the inlet valve for a period before depressurising, as the pressure will drop steadily during this period if there is a leak.
In most cases a permanent set that exceeds the specified maximum will indicate failure. A leak may also be a failure criterion, but it may be that the leak is due to poor sealing of the test equipment. If the vessel fails, it will normally go through a condemning process marking the cylinder as unsafe. The information needed to specify the test is stamped onto the cylinder.Pipeline Safety: Hydrostatic Pressure Testing – Short Version
This includes the design standard, serial number, manufacturer, and manufacture date. After testing, the vessel or its nameplate will usually be stamp marked with the date of the successful test, and the test facility's identification mark.
A simpler test, that is also considered a hydrostatic test but can be performed by anyone who has a garden hose, is to pressurise the vessel by filling it with water and to physically examine the outside for leaks. This type of test is suitable for containers such as boat fuel tanks, which are not pressure vessels but must work under the hydrostatic pressure of the contents. A hydrostatic test head is usually specified as a height above the tank top.
The tank is pressurised by filling water to the specified height through a temporary standpipe if necessary. It may be necessary to seal vents and other outlets during the test. Portable fire extinguishers are safety tools that are required in most public buildings. Fire extinguishers are also recommended in homes. Over time the conditions in which they are housed, and the manner in which they are handled affect the structural integrity of the extinguisher.
A structurally weakened fire extinguisher can malfunction or even burst when it is needed the most. To maintain the quality and safety of this product, hydrostatic testing is utilized.
All critical components of the fire extinguisher should be tested to ensure proper function. Hydrotesting of pipes, pipelines and vessels is performed to expose defective materials that have missed prior detection, ensure that any remaining defects are insignificant enough to allow operation at design pressures, expose possible leaks and serve as a final validation of the integrity of the constructed system.This Safety and Health Information Bulletin is not a standard or regulation, and it creates no new legal obligations.
The Bulletin is advisory in nature, informational in content, and is intended to assist employers in providing a safe and healthful workplace.
In addition, pursuant to Section 5 a 1the General Duty Clause of the Act, employers must provide their employees with a workplace free from recognized hazards likely to cause death or serious physical harm. Two workers recently were killed in accidents that occurred during the de-watering of natural gas pipelines, a process conducted following the construction of the pipelines. The victims were killed when they were struck by temporary de-watering piping, which was not properly anchored and broke loose from its coupling from excessive air pressure.
The Occupational Safety and Health Administration OSHA and the Office of Pipeline Safety OPS urge that all persons working on, or in close proximity to, de-watering processes be alerted to this serious hazard and take appropriate steps to prevent death or serious injury.
The OSHA Allentown and Wilkes-Barre Area Offices recently investigated two fatalities that occurred in conjunction with de-watering processes associated with newly constructed natural gas pipelines. In both cases, the temporary de-watering piping violently separated from its couplings, striking and fatally injuring employees.
In one instance, the separated section of pipe was thrown 45 feet from where it had been attached to the temporary de-watering valve. OSHA determined that a major contributing factor to both of the accidents was temporary de-watering pipelines that were not adequately secured to prevent the piping from moving or separating. In one case, the failure occurred at a pipe coupler that was not being used within the safe tolerances established by the manufacturer.
After a pipeline is laid, a hydrostatic test is conducted to ensure its integrity. Hydrostatic testing may also be conducted during the service life of the pipeline to evaluate its operational integrity. The hydrostatic test consists of pumping water into the pipeline, "pressuring up" the line to specified test pressures, and holding that pressure for a discrete period of time in accordance with applicable regulations and guidelines, including regulations promulgated by OPS.
After completion of the hydrostatic test, the pressure is relieved and the water is removed from the pipeline de-watering. The de-watering process involves connecting a temporary de-watering line figure 1 to the main pipeline with mechanical couplers and adequately securing the temporary de-watering line to prevent displacement.
A de-watering "pig" figure 2 is then forced through the main pipeline using several hundred pounds pressure of compressed air. As the pig is forced through the pipeline with air pressure, the water remaining in the line from hydrostatic testing is pushed out of the main pipeline through the temporary de-watering line.
During the de-watering process, significant and sudden variations in pressure often occur within the main pipeline and temporary de-watering line. These variations can be caused by changes in pig velocity as it passes through bends in the pipeline or changes in pig and water velocity due to changes in pipeline elevation. Compressed air escaping around the pig, which can combine with air already present in the main pipeline at high spots in the pipe, can also create a source for stored energy within the main pipeline.
These sudden pressure changes produce surges that are transferred from the main pipeline to the temporary de-watering line. This can result in movement of the temporary de-watering line, as the pressures can easily exceed the working pressures and bending capabilities of the temporary de-watering line couplers.
The movement of the de-watering line can result in violent failure of the temporary piping system, particularly when the temporary piping is not properly anchored. This situation can be exacerbated when the temporary pipeline suddenly changes direction, when couplers or pipe sections figures 3, 4 and 5 have worn beyond the specified tolerances established by the manufacturer of the de-watering piping system, or when the entire de-watering manifold is inadequately designed for the stresses that can be imposed while de-watering.
OPS regulates pipeline safety, recognizes the existence of hazards associated with testing pipelines, and requires operators to protect their employees and the public during hydrostatic testing. Although OSHA has no specific regulations addressing the design or securing of de-watering piping systems, the Agency is aware of workplace injuries and fatalities caused by improper anchoring or restraining of temporary de-watering pipes.
OSHA's authority is limited by Section 4 b 1 of the Occupational Safety and Health Act OSH Actwhich precludes OSHA from regulating working conditions over which other federal agencies "exercise statutory authority to prescribe or enforce standards or regulations affecting occupational safety or health.
Thus, OSHA's authority to address occupational safety and health hazards associated with pipelines is controlled by the scope and nature of OPS regulations.
In practice, OSHA authority over working conditions associated with pipeline de-watering operations generally is limited to employers e. The potential for separation of a pressurized pipeline is a recognized hazard in related industries and applications. The oil and gas industry has long recognized this hazardous condition in several operations, and there are published consensus industry standards addressing the potential for such failure [1,2,3].
These standards recommend the securing or anchoring of pressurized flow, bleed-off, and blow-down lines to prevent movement. The condition of the couplings, which are used to attach the de-watering pipe to the main gas line and other temporary de-watering pipe sections, likely contributed to one of the accidents that OSHA investigated. In that case, the failure occurred at a pipe coupler that was not within the manufacturer's established tolerances. With the added pressure of the de-watering process, a damaged or improper coupler could contribute to the separation of temporary pipe sections.
It is imperative that all connections and fixtures be in proper working condition.