The boiler in a modern Thermal Power Plant produces steam at very high pressures and temperatures. One of the most important yet simple test that ensures the integrity of the boiler is the ‘Hydrostatic Test’. What is it? How is it done?
A string of catastrophic failures marked the starting era of the steam engine. The boiler explosion in the Grover Shoe Factory in Brockton, Massachusetts on March 10, 1905 triggered the implementation of the boiler safety rules. Today, stringent regulations control the boiler design, materials, manufacture and operation. These are mandatory as per law all over the world.
In a large Thermal Power Plant there are about Ten Thousand tons of steel tubes, pipes, drums and other vessels that contain the high pressure steam. More than Sixty Thousand weld joints make the Boiler an integrated vessel to produce steam. Design calculations, metallurgical inspections and manufacturing inspections assure the integrity of every part and every weld joint. Hydrostatic test is the last of the test to ensure completion , compliance and safety before the boiler produces steam.
The test consists of filling the Boiler with water and pressurizing the water to at least one and half times the maximum operating pressure for a short time. Every part is subject to more than the maximum stress it will normally encounter. This is an endurance test; any weak link fails during the test.
Why do we use water as the media for a hydrostatic test ? Water is the most easily available liquid. There are no environmental or toxic issues. There is another important reason. It is the compressibility or rather the incompressibility of water. Water is almost incompressible. For carrying out the hydrostatic test in large power plant boiler we require around 600 cubic metre of water. Since water is almost incompressible, to increase the pressure form atmospheric to 250 bar we require only an additional amount of one cubic meter of water. This is faster and requires much less effort. In case of the failure of any part the pressure also is reduced immediately preventing further damage.
Ensure that all work is completed and documented. Connect a high pressure positive displacement pump (Hydrostatic pump) to the boiler. Fix a calibrated and accurate pressure gauge to the boiler. All valves and opening in the boiler are closed. Fill the boiler with water using a high capacity filling pump. During filing ensure removal of entrapped air by opening vents at the highest point in the boiler. Entrapped air will drastically increase the time taken to reach the test pressure.
Running the hydrostatic test pump increases the boiler pressure gradually till the test pressure. Normally the test pressure is is 1.5 times the maximum allowable operating pressure. Close the pump discharge valves to lock the system pressure. The pressure in the boiler should maintain without dropping for at least 30 minutes. Bring down the pressure to the normal operating pressure and visually inspect for any signs leakages or wetting of the surfaces. Depending on the size and capacity of the boiler this may take a few hours. After the inspection reduce the pressure gradually to atmospheric and drain the boiler.
Test is witnessed by inspection agencies or regulatory authorities, who then approves and certifies the test.
Mandatory Hydrostatic tests done annually by regulatory authorities are a check on material degradation and ensure the continuous safety of the boiler. Hydrostatic tests are not only for boilers.
Use the same methods to test any pressure vessel or piping that stores or transports pressurised media. This is a simple but very important test which all mechanical and process engineers should know about.
Source: http://www.zgsteamboiler.com/faq/What-is-Boiler-Hydrostatic-Test.html
Pre: What is the use of steam boiler in paper industry?
Next: How to Calculate Gas Consumption in a Gas Boiler Burner?
Packaging Detail:Wooden box package of What is Boiler Hydrostatic Test?
Delivery Detail:20-40 days after payment
We have over 70 years' experience of industrial steam boiler and autoclave, and we have a professional installation and after-sales staff for products.Take advantage of the most economical way to improve efficiency and operating flexibility, Get substantial savings on your fuel costs,Reduce all emissions for each K/W of electricity generated, including CO2.
Our industrial steam boiler manufactured strictly according to national and international standard. our products have approved ASME, IBR, ISO9001-2008, etc
All our company's products are 100% factory inspected to ensure the high quality.
We provide one year quality warranty service, please rest assured purchase.
ZG service ensures that this will not happen. During installation of industrial steam boiler, 1-2 experienced engineering and technical personnel will be sent for the site representative for technical tests and installation instructions free of charge; processing the various problems arising in the course timely while installing.
Established:In 1945
Number of Employees:above 1500 People
Our products:industrial horizontal steam boiler and hot water boiler(biomass boiler, gas boiler, oil boiler, coal boiler, etc), CFB boiler, power plant boiler, waste heating recovery boiler, Pressure Vessel(AAC autoclave, Curing tank,etc )
Factory Size (Sq.meters):400,000 square meters
Factory Location:Factory 1: Zhengzhou,,Henan, China. Factory 2: Xingyang,Henan,China
Number of R&D Staff:376 people
Export Percentage:30-40%
Total Annual Sales Volume:US$100 Million
Main Market:South America(Colombia, Venezuela, Guyana, Suriname, Ecuador, Peru, Brazil, Bolivia, Chile, Paraguay, Uruguay, Argentina and French Guiana), North America(Bahamas, Canada, Costa Rica, Cuba, El Salvador, Guatemala, Honduras, Haiti, Jamaica, Mexico, Nicaragua, Panama), Eastern Asia(Mongolia / Russia / North Korea / South Korea / Japan), Oceania(Australia, New Zealand, Fiji), Mid East(Bahrain, Egypt, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, UAE and Yemen, Palestine, Algeria, Libya, Morocco, Tunisia and Sudan, Mauritania and Somalia), Africa(Egypt, Sudan, Libya, Tunisia, Algeria, Morocco, Ethiopia, Somalia, Kenya, Tanzania, Sierra Leone, Liberia, Cote d'Ivoire, Ghana, Togo, Niger, Nigeria, Cameroon, Gabon, Congo (Brazzaville), Zambia, Zimbabwe, Angola, Mozambique, Botswana, Namibia, South Africa), South Asia(Nepal, Bhutan, India, Pakistan, Bangladesh, Sri Lanka, Maldives) Southeast Asia(Vietnam, Laos, Cambodia, Thailand, Myanmar, Malaysia, Singapore, Indonesia, Brunei, the Philippines, East Timor) Domestic Market(China)
Source: http://www.zgsteamboiler.com/faq/What-is-Boiler-Hydrostatic-Test.html
Pre: What is the use of steam boiler in paper industry?
Next: How to Calculate Gas Consumption in a Gas Boiler Burner?
Get Price And Support
Simply complete the form below, click submit, you will get the price list and a ZG boiler representative will contact you within one business day. Please also feel free to contact us by email or phone. ( * Denotes a required field ).
Email: [email protected]
Tele: +86 17719993430