Plumbing System Controls & Valves
Guide to all types of controls used on plumbing systems
PLUMBING CONTROLS & VALVES
- CONTENTS: Description of common stop valves used on plumbing water supply piping. Drain valves installed on water heaters, water tanks, heating boilers etc. Stop valves installed at plumbing fixtures. Gas and oil piping fuel line stop and control valves & check valves. Links to details about all types of plumbing system valves on supply piping, drain piping, & plumbing fixtures or appliances: check valves, flushometer valves, etc.
Types of Plumbing Valves Used on Water Piping: Globe Valve, Gate Valve, Ball Valve Compared
Thanks to Carson Dunlop Associates, a Toronto Home Inspection Firm and Home Inspection Educator, for permission to use sketches shown in this article.
As Carson Dunlop Associates' illustrations below show, a broken water control valve stem can obstruct or block water flow through the valve. Globe valves (below left) tend to most restrict water flow compared with the gate valve (center) and ball valve (right). But a broken stem on a gate valve can also leave the valve stuck partly or even fully closed (or open), regardless of how you may be able to turn the valve handle.
[Click to enlarge any image]
Also see SHUTOFF VALVE LOCATION, USE for a discussion of how to find, use, & repair building water supply shutoff valves and stop valves.
Drain Valves: boilers, water heaters, water pressure tanks
On heating boilers and steam boilers the drain valve attached on or close to the boiler body is commonly called a boiler drain.
Watch out: Often an unused or rarely-used plumbing valve may be stuck, may have lost an internal washer, and may otherwise fail to close properly if you touch it. We advise against attempting to open or adjust heating equipment drain valves unless you are prepared to shut down the system and install a replacement valve in the event of a leaky valve that can't be shut off.
FLUSHOMETER VALVES for TOILETS URINALS - with adequate water pressure, flow, and volume and proper installation, the flushometer valve eliminates the requirement for a water reservoir tank at toilets and supports urinals in restrooms
Plumbing & Heating Controls Valves, Service Valves, Safety Valves
MIXING / ANTI-SCALD VALVES - found on tankless coils used for making domestic hot water and at other hot water supply systems that produce very hot water; also found installed directly at some plumbing fixtures such as sinks, tubs, and showers.
Watch out: do not touch, open, or otherwise manipulate relief valves on heating equipment unless you are prepared, should the valve leak, to shut down the heater and replace the leaky valve immediately.
Electric Solenoid Operated Gas, Oil, Water Valves used in Buildings
Here we describe electrically operated plumbing valves used for water control of equipment or piping in buildings.
Reader Question: where can I buy a solenoid-operated water shut-off valve?
15 January 2015 Martin said:
We have a water break tank in basement cant get overflow out.We have been told we can drop a over flow from the large tank into a smaller header tank.
A flow detector is then place in the smaller tank and then connected to the incomming water main via a solenoid valve which would turn off water supply. Any ideas where I can purchase solenoid-operated water shut-off valves?
Martin a number of companies provide electrically-operated solenoid-type shutoff valves including valves that can close off a water supply line. The operating pressure range and piping diameters among the various products vary so you’ll want to contact the company’s technical or sales people to discuss your specific needs.
Prices for electric solenoid valves range from under $50. U.S.D. to over $500. U.S.D. depending on the application.
Watch out: check the solenoid valve specifications carefully to match against your system's needs, including at least the following:
Suitability for handling the liquid you are controlling
Operating pressure range of the solenoid water valve
Operating voltage ranges of the solenoid valve: for example low-voltage 12VAC, 12VDC, 18VAC, 24VAC, or household current levels of 120VAC 50/60Hz ot 208-240VAC 50.60 Hz
Valve default position: normally OPEN or normally CLOSED
Use of lead in the valve components - may be unsuitable for some locations or may be prohibited by local plumbing codes
Where to Buy Electrically Operated or Solenoid Operated Water Control Valves
InspectAPedia is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information provided free to the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website.
Alcon Solenoid Valves,
Alcon is an IMC Company, products include valves for air, water, gases, fuel, hot water, steam, cryogenics, aggressive media.
Alcon 12AZ041A1-1GCA electronic shut-off solenoid valve, 115VAC normally closed (other models are normally open)
Worldwide distribution including North America and the U.K. R
Telephone: +44 1225 733200
Fax: +44 1225 333467
USA Tel: 1-888-307-0708
Canada: Contact www.pneumac.qc.ca
Amico multi-position and two position DC24V solenoid valves
Asco Red Hat Water Shutoff Solenoid Valve
Emerson Industrial Automation - (focus on fuel shutoff valves for heating applications).
50-60 Hanover Road
Florham Park, NJ 07932
Tel: (866) 298-3559
Burkert Fluid Control Systems produces a wide range of solenoid valves controlling high pressure systems, steam systems, water systems, and general purpose solenoid-operated valves.
Burkert Contromatic Corp.
2915 Whitehall Park Drive, Suite 650
Charlotte, NC 28273
Tel: 1-855-BURKERT (287-5378)
BVA Hydraulics solenoid valves
Dayton Solenoid Valves, distributed also by Grainger Industries (http://www.grainger.com/) operate at 120VAC or 208/240 VAC 50/60 Hz and are used at water pressures up to 300 psi.
Elk Professional Grade water shutoff valves
ELK Products, Inc.
P.O. Box 100
Hildebran , N.C. 28637
Tel: (800) 797-9355
USA Tel: 877-335-3339
Electronic Shut-off Solenoid Valve with QC fittings: Feed water control valve is used in combination with the tank and the pump pressure switch to automatically close OFF the feed water source when the RO tank is full.
Garland Group solenoid valves
GE General Electric solenoid water control valves
Haldex-Barnes solenoid valves
Honeywell Water shutoff solenoid valve (industrial scale) Magnetic Solenoid Valve MV300
STC provides a complete line of air, water, liquid, steam process control valves.
Sizto Tech Corporation 892 Commercial Street, Palo Alto, CA 94303 USA
TFGS: Takasago Fluidic Systems, provides more than 5000 types of control valves including miniature valves used in medical and analytical instruments.
Vktch electric solenoid valves for controlling water flow
Watts water shutoff & flow control valves including water shutoffs and washing machine shutoff valves Corporate Headquarters Watts 815 Chestnut Street North Andover, MA, USA 01845-6098
Canadian Office Watts 5435 North Service Road Burlington, Ontario, Canada L7L 5H7
Other Electrical & Solenoid Valves used in Buildings & on Building Mechanical Systems
Examples of other types of electrically operated or solenoid operated valves used in buildings include
Our complete list of types of control valves use in buildings and on building mechanical systems is found at MORE READING.
Other Plumbing System Control Valves
CHECK VALVES, WATER SUPPLY or backflow preventers are used on on water supply piping are used on well piping systems to prevent back-contamination of the public water supply. Note that in many jurisdictions use of a conventional check valve is not a suitable substitute for a backflow preventer..
Reader Question: Installing a pressurized system & Flushometer Valve Toilets & Urinals on a Well & Pump Water Supply System
I have a well system at a marina and would like to install commercial flushometer toilets and urinals. It is old and is currently served by a standard residential system.
I have space above the rest rooms and would like to install a stand alone pressurized system that is fed by the existing residential system, but would provide the gpm and pressure to function the commercial units. Likely to be a total of 3 toilets and two urinals.
Any ideas or plans available? Thanks, Bill
Reply: Be sure that your well water supply system, pressure tank, pressure, and water supply piping diameter & flow rate can support flushometer valves; consider waterless urinal fixtures.
Bill, there is no technical reason why one could not install flushometer type toilets and urinals at a property served by a standard pump and well system, but the cost and trouble may be more than first meets the eye. Where we find flushometer type toilets and urinals installed it's usually at a building served by municipal water supply and employing larger diameter water supply piping than the 1/2" pipe usually found at residential type properties.
That's because flushometer fixtures, relying on both water pressure and total gpm flow rate to work properly, need a higher pressure and total flow rate than most residential systems deliver. You can achieve the necessary pressure and water quantity for the fixtures by adding a water tank and pump at a suitable location, but you might need also to install larger diameter water supply piping to each fixture.
Reader Question: what's the purpose of the inline float valve at the top of an electric water heater? Can I remove it?
What is purpose of & is it necessary ? In- line ball- cock valve in water entry line going into top of electric water heater. Would it be ok to eliminate line containing floating ball ? It sticks & completyely restricts my hot water flow. - Randall Doran
Reply: thermosiphon prevention device?
I'm guessing from your description that you are describing an anti-siphon valve at the top of your water heater. The valve is intended to prevent hot water from circulating up into the building water supply piping by "gravity" (warm or hot water, being less dense than cold water, will naturally rise up out of a hot water tank into cooler water in building piping).
If that's what you've got you could remove the valve but the result might be wasted energy - sending hot water out into building piping (where it will cool off) when no hot water is being drawn at a plumbing fixture.
In general you could eliminate a control valve feeding water into your water heater, but it will make it impossible to turn off "hot" water in the building when service or repair to the heater is needed - you'll instead have to turn off water to the whole building.
Watch out: An improperly installed shutoff valve on a water heater can be very dangerous, risking an explosion. Usually the "hot water tank shutoff valve" is installed only on the cold water pipe coming into the water tank. There should be no shutoff valve installed on the hot water line leaving the water tank.
See WATER HEATER SAFETY
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Thanks to reader - R.S. (anonymous by req.) for discussing hot water loss problems - August 2010
 Sloan Valve Company, 10500 Seymour Ave., Franklin Park IL 60131, Tel: 847-671-4300, website: sloanvalve.com
 Sloane-Regal Installation Instructions for Standard Exposed Closet and Urinal Flushometers, Regal I.I. Code 816312, Models 110/111 through Model 117. 120-122, and 180, 186, 1997, Sloan Valve Company, 10500 Seymour Ave., Franklin Park IL 60131, Tel: 847-671-4300, website: sloanvalve.com
 Sloane Installation Instructions for Exposed Regal® XL Water Closet and Urinal Flushometers, Code 0816312 (newer version of above document), Rev. 1 05/10, Sloan Valve Company, 10500 Seymour Ave., Franklin Park IL 60131, Tel: 800-982-5839, or 888-SLOAN-14 / 888-756-2614, website: sloanevalve.com
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: firstname.lastname@example.org. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
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TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
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.
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