|
|
Water Tank Pressure Relief Valves
|
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.
This article describes Water Tank Pressure Relief Valves - how to find buy, or where to install safety valves on water tanks and on well water systems. We explain where a pressure relief valve is usually installed on well water pressure tanks, how the valve works, and why pressure relief valves are an important safety feature on well tanks.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
WATER TANK PRESSURE RELIEF VALVES: installation, inspection, troubleshooting, repair, code requirements for
Safety warning: all pressurized tanks should have an appropriate pressure relief valve installed to avoid
possible injury should the tank burst. In this photo the brass fitting to the right of the black
tank drain is a pressure relief valve installed in the correct location.
Notice that there is no
shutoff valve of any kind installed between the relief valve and the pressure tank?
If the pressure relief valve is leaking this is an UNSAFE condition (corrosion or mineral deposits could
block the valve and prevent its operation in an emergency). The valve should be replaced. |
Early in our building inspection career plumbers in our area were skeptical when we identified
the absence of a pressure relief valve as a safety concern (and a building or plumbing code violation).
Then in about 1984 a local plumber was killed by a bursting water pressure tank.
The water pump
was a submersible unit located (remotely) inside of the water well. The plumber was leaning over
the water tank repairing a fitting, unaware that the water pump had turned on, and unaware that
the pressure control switch had been damaged or modified so that it failed to turn off the
water pump at a safe pressure.
The water tank burst, metal fragments severely injured the plumber who,
working alone, bled to death. After that terrible event all of our local plumbers took this
relief valve requirement seriously.
How to Buy & Install the Right Water Tank Pressure Relief Valve for Water Storage Tanks or Water Pressure Tanks
Question: What size or capacity of pressure relief valve should be installed on a water pressure tank?
My water tank pressure switch is set to 20 - 40 psi. How do I gage the size of a relief valve I need to put for my tank? - D.R.
Reply: typical water tank pressure relief valves are 1/2" or 3/4" in diameter orifice and are set to open at 75 psi.
The water tank pressure relief valve shown in our photo (above) is marked indicating that it will open at water pressure equal to or greater than 75 psi. That pressure is pretty standard and you'll see the 75 psi figure on valves used on water tanks and on some tankless water heaters too.
According to the Water Systems Council, [quoting, paraphrasing, and expanding - Ed.]
High pressure in a building water supply system can result if the water pressure switch that controls the well pump is damaged, or if the pump stays on too long.
Most submersible well water pumps can develop pressure exceeding the rated working limits of the water pressure tank or building water distribution system piping, fittings, and fixtures. Excess water pressure can damage water system component as well as the pressure tank if not corrected immediately, and can also cause leaks within the piping system or at faucets and fixtures. Therefore on all building water supply systems using a private well and pump, a pressure-relief valve is recommended.
Water pressure relief valves are spring-controlled and open only in response to system pressure. That is, water temperature is not a controlling factor for these valves. For water service, these important safety devices are generally adjusted to relieve pressure higher than 75 psi. [1]
Watch out: water pressure tank fatality: we [Ed] are aware of a fatality that occurred in the Hudson Valley of New York State when a plumber, working alone on a water pressure tank and pump system was killed as the water pressure tank burst. There was no pressure relief valve on the water system; a submersible well pump was installed; the well pump pressure control switch stuck in the "on" position. We suspect that because the submersible pump was located inside the well and thus there was little or no operating noise when the pump was on, the plumber had no idea that the pump was running. When the pressure inside the water tank exceeded the tank's design specifications the tank burst open. The plumber, leaning over the water tank to perform some task, was cut and killed by the "shrapnel" formed when the water tank burst. - ED.
Examples of water tank and similar pressure relief valves include
- Watts 53 pressure relief valves in 1/2-in NPT and 3/4-in NPT. Model 53L includes a test or relief lever. Quoting from Watts® product literature for this product:
Watts Series 53 Pressure Relief Valves are spring operated
bronze relief valves designed to be used only as protection
from the build up of excessive pressure in systems containing
water, oil or air. These valves are not ASME approved
safety relief valves and should not be used in system applications
with this requirement. They feature all bronze construction
with stainless steel springs. Series 53 have standard
pressure settings of 75, 125, and 150psi (5.2, 8.6 and
10.3 bar). They are also specially available at 50psi (3.4 bar)
setting. Pressure range is 75-175psi (5.2-12.1 bar). - Watts®
- Watts530C (calibrated pressure relief valves) and LF530C, lead free calibrated pressure relief valves. Product literature quote:
Series LF530C Lead Free* Calibrated Pressure Relief Valves are used in commercial, residential and industrial applications to protect against excessive pressure in systems containing water, oil, or air. It consists of a Lead Free* brass body construction with NPT threaded male inlet and NPT threaded female (drain) outlet connections, stainless steel spring, brass bonnet, Buna-N disc, and Buna-N O-ring. Series LF530C has a calibrated adjustment feature for setting the valve to the required relief pressure, and is ideal for by-pass thermal expansion pressure relief (not ASME approved). Maximum Pressure: 300psi (20.67 bar). Adjustable Pressure Ranges: Sizes 1/2, 3/4 in. - 50 to 175psi (3.45 to 12.06 bar), Size 3/4 in. - 100 to 300psi (6.89 to 20.67 bar). - Watts®
These valves are also used for bypass thermal expansion relief as we describe below at the Watts 30L.
- Watts 30L Pressure Relief Valves for Well Systems, with test lever. These valves, intended for protection against excessive pressure in well water systems, are designed for pressure relief only [compared with pressure and temperature relief valves that should be used on water heating equipment - see RELIEF VALVES - Water Heaters or relief valves used on heating boilers RELIEF VALVES - TP Valves on Boilers] Quoting from Watts product literature:
Series 30L Pressure Relief Valves for Wells are used to protect against excessive pressures in well systems. It is not diaphragm actuated and is used for pressure-relief service only. Series 30L consists of a bronze body construction with NPT threaded male inlet and NPT threaded female (drain) outlet connections, stainless steel spring, and test lever. Standard Pressure Setting: 75psi (5.17 bar), Optional Settings: 100, 125, and 150psi (6.9, 8.6, and 10.3 bar). - Watts®
These valves are installed as an auxiliary bleeder pressure relief valve to provide relief of increased water pressure due to thermal expansion, and they are typically installed on a hot water supply pipe downstream from the water heater and over a laundry sink or drain. Watts points out in their product literature that these valves are also installed on cold water piping.
But check with the manufacturer of your water tank to determine if a different relief valve opening pressure is required.
Standard water tank pressure relief valves are sold at plumbing suppliers and are pre-set with a "safe" pressure for most home water tanks, provided that the water tank, piping, and controls are properly installed and adjusted.
A professional plumber would select and install a water tank pressure relief valve that opens to spill water and relieve pressure at a point well below the rated burst pressure of the tank.
The burst-pressure of a water tank, provided it's undamaged and properly installed, should be well above the opening pressure on the tank relief valve. But to choose a specific valve matched to your water tank, you should consult the manual for your water tank and pump and their manufacturer to be sure you've got the right part.
If a pressure relief valve is not installed on your water tank ask your plumber to provide
one promptly.
...
Frequently Asked Questions (FAQs)
...
Ask a Question or Search InspectApedia
Questions & answers or comments about the requirement for pressure relief valves on well water pressure tanks
Ask a Question or Enter Search Terms in the InspectApedia search box just below.
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.
- Watts Corporation, Series 53 Pressure Relief Valves, for commercial and residential applications, publication ES-53 1010, Watts Corporation, 815 Chestnut St., No. Andover, MA 01845-6098; www.watts.com and Watts Corporation in Canada: 5435 North Service Rd., Burlington, ONT. L7L 5H7; www.wattscanada.ca.
Web search 03/24/2011, original source: http://media.wattswater.com/ES-53.pdf and also http://media.wattswater.com/1910868.pdf
Note: The Watts products shown on the first cited product page are small type relief valves.
Construction of these products does not meet the (ANSI Z21.22)
nationally recognized applicable standard.
- [1] wellcare® information for you about Well Components: Valves, web search 12/3/2011, original source: http://www.watersystemscouncil.org/
VAiWebDocs/WSCDocs/789912Valves_FINAL_507.pdf
- Access Water Energy, PO Box 2061, Moorabbin, VIC 3189, Australia, Tel: 1300 797 758, email: sales@accesswater.com.au Moorabbin Office: Kingston Trade Centre, 100 Cochranes Rd, Moorabbin, VIC 3189
Australian supplier of: Greywater systems, Solar power to grid packages, Edwards solar systems, Vulcan compact solar systems, water & solar system pumps & controls, and a wide rage of above ground & under ground water storage tanks: concrete, steel, plastic, modular, and bladder storage tanks.
- Smart Tank, Installation Instructions [ copy on file as /water/Smart_Tank_Flexcon.pdf ] - , Flexcon Industries, 300 Pond St., Randolph MA 02368, www.flexconind.com, Tel: 800-527-0030 - web search 07/24/2010, original source: http://www.flexconind.com/pdf/st_install.pdf
- Typical Shallow Well One Line Jet Pump Installation [ copy on file as /water/Jet_Pump_Grove_Elect_Jet_Pumps_1.pdf ] - , Grove Electric, G&G Electric & Plumbing, 1900 NE 78th St., Suite 101, Vancouver WA 98665 www.grovelectric.com - web search -7/15/2010 original source: http://www.groverelectric.com/howto/38_Typical%20Jet%20Pump%20Installation.pdf
- Typical Deep Well Two Line Jet Pump Installation [ copy on file as /water/Jet_Pump_Grove_Elect.pdf ] - , Grove Electric, G&G Electric & Plumbing, 1900 NE 78th St., Suite 101, Vancouver WA 98665 www.grovelectric.com - web search -7/15/2010 original source: http://www.groverelectric.com/howto/38_Typical%20Jet%20Pump%20Installation.pdf
- Water Fact Sheet #3, Using Low-Yielding Wells [ copy on file as /water/Low_Yield_Wells_Penn_State.pdf ] - , Penn State College of Agricultural Sciences, Cooperative Extension, School of Forest Resources, web search 07/24/2010, original source: http://pubs.cas.psu.edu/FreePubs/pdfs/XH0002.pdf
- Watts Corporation, Series 53 Pressure Relief Valves, for commercial and residential applications, publication ES-53 1010, Watts Corporation, 815 Chestnut St., No. Andover, MA 01845-6098; www.watts.com and Watts Corporation in Canada: 5435 North Service Rd., Burlington, ONT. L7L 5H7; www.wattscanada.ca.
Web search 03/24/2011, original source: http://media.wattswater.com/ES-53.pdf and also http://media.wattswater.com/1910868.pdf
Note: The Watts products shown on the first cited product page are small type relief valves.
Construction of these products does not meet the (ANSI Z21.22)
nationally recognized applicable standard.
- Crystal Clear Supply provides portable ceramic water filter purifiers and portable reverse osmosis water treatment equipment - see http://www.crystalclearsupply.com/category_s/7.htm
- Handbook of Disinfectants and Antiseptics, Joseph M. Ascenzi (Editor), CRC, 1995, ISBN-10: 0824795245 ISBN-13: 978-0824795245 "The evaluation of chemical germicides predates the golden age of microbiology..." -
This well-focused, up-to-date reference details the current medical uses of antiseptics and disinfectants -- particularly in the control of hospital-acquired infections -- presenting methods for evaluating products to obtain regulatory approval and examining chemical, physical, and microbiological properties as well as the toxicology of the most widely used commercial chemicals.
- Potable Aqua® emergency drinking water germicidal tablets are produced by the Wisconsin Pharmacal Co., Jackson WI 53037. 800-558-6614 pharmacalway.com
- Principles and Practice of Disinfection, Preservation and Sterilization (Hardcover)
by A. D. Russell (Editor), W. B. Hugo (Editor), G. A. J. Ayliffe (Editor), Blackwell Science, 2004. ISBN-10: 1405101997, ISBN-13: 978-1405101998.
"This superb book is the best of its kind available and one that will undoubtedly be useful, if not essential, to workers in a variety of industries. Thirty-one distinguished specialists deal comprehensively with the subject matter indicated by the title ... The book is produced with care, is very readable with useful selected references at the end of each chapter and an excellent index. It is an essential source book for everyone interested in this field. For pharmacy undergraduates, it will complement the excellent text on pharmaceutical microbiology by two of the present editors."
The Pharmaceutical Journal: "This is an excellent book. It deals comprehensively and authoritatively with its subject with contributions from 31 distinguished specialists. There is a great deal to interest all those involved in hospital infection ... This book is exceptionally well laid out. There are well chosen references for each chapter and an excellent index. It is highly recommended." The Journal of Hospital Infection.: "The editors and authors must be congratulated for this excellent treatise on nonantibiotic antimicrobial measures in hospitals and industry ... The publication is highly recommended to hospital and research personnel, especially to clinical microbiologists, infection-control and environmental-safety specialists, pharmacists, and dieticians."
New England Journal of Medicine: City Hospital, Birmingham, UK. Covers the many methods of the elimination or prevention of microbial growth. Provides an historical overview, descriptions of the types of antimicrobial agents, factors affecting efficacy, evaluation methods, and types of resistance. Features sterilization methods, and more. Previous edition: c1999. DNLM: Sterilization--methods.
- U.S. Army Field Manual 21-10, Field Hygiene and Sanitation, 1988, web search 07/02/2010, original source: http://www.enlisted.info/field-manuals/fm-21-10-field-hygiene-and-sanitation.shtml
The purpose of this manual is to assist individual soldiers, unit commanders, leaders and field sanitation teams in preventing disease and environmental injuries. The manual provides information on preventive medicine measures (PMM) to the individual soldier as well as essential information for the unit commander, unit leaders, and the unit field sanitation team on applying unit level PMM.
- When Technology Fails, Matthew Stein, Chelsea Green Publisher, 2008,493 pages. ISBN-10: 1933392452 ISBN-13: 978-1933392455, "... how to find and sterilize water in the face of utility failure, as well as practical information for dealing with water-quality issues even when the public tap water is still flowing". Mr. Stein's website is www.whentechfails.com/
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
 The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.
|
|
