17_Water Pressure Reducing Valves

Water Pressure Reducing Valves

Ensuring Practical, Safe Working Water Pressures Municipal and private water supply companies use pumps and pumping stations to boost water supply pressures in supply mains to be able to supply water for fire fighting, high rise buildings to overcome loss of pressure as the elevation increases, and to maintain water supply in water towers and supply tanks. Pressure in water supply mains can exceed 200psi. Most plumbing codes require water pressure reducing valves on domestic systems where the municipal water main's pressure exceeds 80psi. Higher pressures could rupture pipes, damage fixtures,and injure the people using them.

How Does a Pressure Reducing Valve Work?

Installed directly after the water meter in homes, commercial buildings, and manufacturing plants, a water pressure reducing valve automatically reduces the pressure from the water supply main to a lower, more sensible pressure.

Water entering the valve from municipal mains is constricted within the valve body and directed through the inner chamber controlled by an adjustable spring loaded diaphragm and disc. Even if the supply water pressure fluctuates, the pressure reducing valve ensures a constant flow of water at a functional pressure, as long as the supply pressure does not drop below the valve's pre-set pressure.

Sizing a Water Pressure Reducing Valve for Your Application

A properly sized valve prevents noisy operation ("water hammer" banging or whining pipes) or premature valve failure. 

Choosing the Correct Installation Configuration

Water pressure reducing valves can increase your water system's performance, reduce operating costs, and ensure a longer life for other plumbing fixtures. Most simple pressure reducing applications require the installation of a single regulator. 

Source: http://www.watts.com/pages/learnAbout/reducingValves.asp?catId=64#whatiswprv

Testing Water Pressure

Gauges like this one are available from your favorite home improvement center for less than $10 (0-120psi).  Be sure no water is being used in the house while you are testing - to get an accurate STATIC pressure reading. Attach the gauge, turn on the faucet, take the reading, turn off the faucet and disconnect the gauge.  You can also call your water supplier and ask them what it should be in your area.  The ideal pressure for inside fixtures is around 50 psi.  The PRV can be adjusted with the bolt to output different amounts of pressure.  Reduce the pressure to save water and extend the useful life of fixtures.

How much does a typical family of four use?

A typical family of four uses an average of 255 gallons of water each day for interior plumbing. This is broken down by:

• dishwashing -        15 gallons;
• cooking/drinking -  12 gallons;
• utility sink -             5 gallons;
• laundry -               35 gallons;
• bathing -               80 gallons;
• bathroom sink -       8 gallons;
• toilet -                 100 gallons.

When you multiply this by a year, typical family usage totals 93,000 gallons of water. Your family particularly if it includes teenagers, would undoubtedly use more than the above averages.

How long will a Regulator last?

Regulators have been described as "life-of-mortgage" products, because historically a malfunctioning pressure regulator is not replaced but simply cleaned or repaired via an inexpensive service kit. Design wise, it is similar to the kitchen faucet in that dirt or foreign matter on the seating area can cause problems and actually it is no more difficult to repair a regulator than it is to fix the kitchen faucet.

Over time, some valves can wear out and if replacement is required expect approximately $50 + labor.  I suggest buying from a plumbing supply specialty store, as there are many models available.  

Want to read more: http://www.irrigationtutorials.com/sprinkler03.htm
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Clarifying Note: Pressure Relief Valves (PRV) also exist as a safety feature for hot water tanks, and are NOT what is being discussed in this article.

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Addition: 

Fluidmaster S2DBL Dual FlushToilet Conversion Kit

Between $30-40

"FLUIDMASTER" COMPLETE WATER SAVING DUAL FLUSH CONVERSION KIT 
*Converts your existing toilet to dual flush.
* Uses up to 45% less water.
* Fully adjustable for a wide range of applications.
* Adjustable Dual Float System delivers precise and powerful flushing action.
* Complete system includes: flush and fill valves and all installation accessories.
* Water Level Adjusting screw for best flush
* Durable Silicon seal for year of dependable flushes
* Has a Full and Half  flush for water savings you can see.

Turn the average 100 gallons per day of water usage at the toilet (for a family of four) into 50!
Available at: Lowe's, Home Depot, Ace Hardware and online.