question: Does reducing the water pressure at the pressure regulator reduce the amount of water used at the faucet/shower head?
comment: More pressure (Head) is more flowrate. If you turn on shower for 5 minutes when pressure is lowered you use less water in that time. But if you want to fill a bucket, it dosent mater what the pressure you use, it needs same amout of water. Pressure will imapct the time you need to fill the bucket. So if want to last hot water longer you need to reduce the pressure.
passages: If, for example, someone flushes a toilet while the shower is in use, the fixture suddenly draws a significant amount of cold water from the common supply line, causing a pressure drop. In the absence of a compensating mechanism, the relatively higher pressure in the hot water supply line will cause the shower temperature to rise just as suddenly, possibly reaching an uncomfortable or even dangerous level. Conversely, if someone opens a hot water faucet elsewhere, the relatively higher pressure in the cold water supply line will cause the shower temperature to drop suddenly.
   The pressure-balanced shower valve compensates for changes in water pressure. It has a diaphragm or piston inside that reacts to relative changes in either hot or cold water pressure to maintain balanced pressure. As water pressure drops on one supply line, the valve reduces the pressure in the other supply line to match. A side effect of this is that the pressure and flow at the shower head or tub spigot will drop twice as much as if only one supply line had been affected, but without a large temperature change. There are ball bearings in the valves to regulate forces.
   Section::::Applications.:Water pressure reduction.
  
  Often, water enters water-using appliances at fluctuating pressures, especially in remote locations, and industrial settings. This pressure often needs to be kept within a range to avoid damage to appliances, or accidents involving burst pipes/conduits. A single-stage regulator is sufficient in accuracy due to the high error tolerance of most such appliances. Also used in applications where the water supply reservoir is significantly higher in elevation to the end of the line. e.g. underground mine water supply.
  
  Section::::Applications.:Oxy-fuel welding and cutting.
   For recreational vehicles with plumbing, a pressure regulator is a necessity. When camping, a source of water may have an enormous pressure level, particularly if it comes from a tank that is at a much higher elevation than the campground. Water pressure is dependent on how far the water must fall. Without a pressure regulator, the intense pressure encountered at some campgrounds in mountainous areas may be enough to burst the camper's water pipes or unseat the plumbing joints, causing flooding. Pressure regulators for this purpose are typically sold as small screw-on accessories that fit inline with the hoses used to connect an RV to the water supply, which are almost always screw-thread-compatible with the common garden hose.
   If the load flow decreases, then the regulator flow must decrease as well. If the load flow increases, then the regulator flow must increase in order to keep the controlled pressure from decreasing due to a shortage of gas in the pressure system.
  
  A pressure regulator includes a "restricting element", a "loading element", and a "measuring element":
  
  BULLET::::- The restricting element is a valve that can provide a variable restriction to the flow, such as a globe valve, butterfly valve, poppet valve, etc.
   BULLET::::- Test by internal pressure (simulation of decompression). Remove the crown together with the winding and/or setting stem. In its place, fit a crown of the same type with a hole. Through this hole, introduce the gas mixture which will actually be used and create an overpressure of the rated pressure/20 bar in the watch for a period of 10 hours. Then carry out the test at the rated water overpressure. In this case, the original crown with the stem shall be refitted beforehand. After this test, the watch shall function correctly.
   Movement induced dynamic pressure increase is sometimes the subject of urban myths and marketing arguments for diver's watches with high water resistance ratings. When a diver makes a fast swimming movement of 10 m/s (32.8 ft/s) (the best competitive swimmers and finswimmers do not move their hands nor swim that fast) physics dictates that the diver generates a dynamic pressure of 50 kPa or the equivalent of 5 metres of additional water depth.
   An example of where backflow would harm the water supply is the use of well washing devices inside underground sewerage pumping stations. At times untreated sewerage may contain a variety of harmful gases that will effectively break down and deteriorate concrete wells, hence well washers are utilised to spray water and wash down contaminated concrete walls of a well. All well washers are installed with RPZ Devices in case a pumping station breaks down, and the sewerage level rises above the well washer, causing backflow down the water supply line.
   Most Moen kitchen, washbasin, and bathtub/shower faucets are of the single-handle design, and almost all have used the same basic water-controlling cartridge since the 1960s. Known as the Moen 1225, it is a plastic (older versions were brass) cylinder approximately 4 inches long by 3/4 inches in diameter. As the "engine" in most Moen single-handle faucets, it has undergone at least two revisions since its inception though newer versions remain compatible with older faucets. Pulling up the stem of the cartridge opens the water supply; rotating toward the left opens the hot water passages while rotating to the right opens the cold water passages (using the standard North American convention of the hot water control on the left).
   A shower head is a perforated nozzle that distributes water over solid angle a focal point of use, generally overhead the bather. A shower uses less water than a full immersion in a bath. Some shower heads can be adjusted to spray different patterns of water, such as massage, gentle spray, strong spray, and intermittent pulse or combination modes. Hard water may result in calcium and magnesium deposits clogging the head, reducing the flow and changing the spray pattern. For descaling, various acidic chemicals or brushes can be used or some heads have rubber-like jets that can be manually descaled. A homemade remedy is to immerse it in a solution of water and vinegar for a while, since the vinegar is able to dissolve limescale. Some governments around the world set standards for water usage and regulate shower heads. For example, in the United States, residential and most commercial shower heads must flow no more than 9.5 liters per minute (2.5 gallons per minute) per the Department of Energy ruling 10 CFR 430. Low-flow shower heads, less than or equal 7.6 liters per minute (2.0 gallons per minute), can use water more efficiently by aerating the water stream, altering nozzles through advanced flow principles or by high-speed oscillation of the spray stream. USEPA administers a voluntary water saving program, WaterSense, which can certify low-flow shower heads.
   In dust control systems (bag filter), a pressure switch is mounted on the header which will raise an alarm when air pressure in the header is less than necessary. A differential pressure switch may be installed across a filter element to sense increased pressure drop, indicating the need for filter cleaning or replacement.
  
  Section::::Pressure sensitive mat.
   Section::::Circulator pump potential side effects.
  
  It is important to take note of the increased heat in the piping system, which in turn increases system pressure. Piping that is sensitive to the water condition (i.e., copper, and soft water) will be adversely affected by the continual flow. Although water is conserved, the parasitic heat loss through the piping will be greater as a result of the increased heat passing through it.
  
  Section::::Quantitative measures of function.
   In water supply systems, water is normally maintained at a significant pressure to enable water to flow from the tap, shower, or other fixture. Water pressure may fail or be reduced when a water main bursts, pipes freeze, or there is unexpectedly high demand on the water system (for example, when several fire hydrants are opened). Reduced pressure in the pipe may allow contaminated water from the soil, from storage, or from other sources to be drawn up into the system.
  
  Section::::Terminology.
   Later Moen bathtub/shower controls with single handles use a larger cartridge with a pressure balancing mechanism which compensates for sudden pressure changes in either the hot or cold water supply (as caused by a toilet being flushed while someone is showering). The design goal is to maintain the temperature of the shower for safety and comfort reasons, even if the volume of water is reduced. The cartridge is known as the 1222. The operation is similar to the 1225 (above), though the cartridge is approximately 1 inch in diameter to allow space for the pressure balancing mechanism.
   Unlike ordinary PWRs, the pressurizer is not contained in a separate vessel and connected to the primary side, but rather is the top of the pressure vessel itself. Water line will be at some preset value, and then sprays and boilers within the pressurizer can be used to control pressure and water level. The unique aspect of this is that the pressurizer is of much greater volume than current plants, which helps to keep the pressure constant in accident situations.
  
  Section::::Reactor Coolant System.:Steam Generator.
   The original twin-hose regulators usually had no ports for accessories, though some has a high pressure port for a submersible pressure gauge. Some later models have one or more low-pressure ports between the stages, which can be used to supply direct feeds for suit or BC inflation and/or a secondary single hose demand valve, and a high pressure port for a submersible pressure gauge. The new Mistral is an exception as it is based on the Aqualung Titan first stage. which has the usual set of ports.
   When the required charge pressure has finally been calculated it is converted to the PWM signal that controls the solenoid valve, The ECU then controls that the actual pressure (measured by the pressure sensor) corresponds with the required pressure. If needed the PWM is fine tuned by multiplication of a correction factor. The correction factor (adaptation) is then stored in the memory of the ECU and is always used in the calculation of the PWM signal. The rationale with this is to make sure that the actual pressure as soon as possible will be equal to the required after a change of the load has occurred.
   DIN valves are produced in 232 bar and 300 bar pressure ratings. The number of threads and the detail configuration of the connections is designed to prevent incompatible combinations of filler attachment or regulator attachment with the cylinder valve.
  
  BULLET::::- 232 bar DIN (5-thread, G5/8) Outlet/Connector #13 to DIN 477 part 1.
  
  BULLET::::- 300 bar DIN (7-thread, G5/8) Outlet/Connector #56 to DIN 477 part 5 - these are similar to 5-thread DIN fitting but are rated to 300 bar working pressures. The 300 bar pressures are common in European diving and in US cave diving.
  
  Adapters
   BULLET::::- If formula_16 and formula_21, we observe that the pressure head is again positive, predicting that the venturi meter shown above would look the same, only upside down. In this situation, gravity causes the working fluid to plug the siphon holes, but the fluid does not leak out because the ambient pressure is greater than the pressure in the pipe.
  
  BULLET::::- The above situations imply that the Bernoulli equation, from which we obtain static pressure head, is extremely versatile.
  
  Section::::Applications.
  
  Section::::Applications.:Static.
   Step 7 :- Solve the continuity equation for the entire control volume. i.e. n,s,e,w nodes surrounding each node of the staggered grid, using the density terms.
  
  Step 8 :- Substitute the corrected velocity equations in the continuity equations and separate the term containing the correction pressure p'.
  
  This represents the equation for pressure correction p'.
  
  Step 9 :- Solve the thus obtained equation to get the correction term and get the correct pressure. Use the new correct pressure to reiterate the entire process till a convergence is obtained.
  
  The choice of α decides the cost effectiveness of the solution.
   Section::::Household applications.
  
  The Home Water Works website contains useful information on household water conservation. Contrary to the popular view that the most effective way to save water is to curtail water-using behavior (e.g., by taking shorter showers), experts suggest the most efficient way is replacing toilets and retrofitting washers; as demonstrated by two household end use logging studies in the U.S.
  
  Water-saving technology for the home includes:
  
  BULLET::::1. Low-flow shower heads sometimes called energy-efficient shower heads as they also use less energy
   However, unlike a pressurized water reactor which contains no steam in the reactor core, a sudden increase in BWR steam pressure (caused, for example, by the actuation of the main steam isolation valve (MSIV) from the reactor) will result in a sudden decrease in the proportion of steam to liquid water inside the reactor. The increased ratio of water to steam will lead to increased neutron moderation, which in turn will cause an increase in the power output of the reactor. This type of event is referred to as a "pressure transient".
  
  Section::::Safety systems.
   Section::::Applications.:Gas powered vehicles.
  
  No matter what type of motor (internal combustion engine or fuel cell electric powertrain) a specific pressure regulator will be necessary to bring the stored gas (CNG, Hydrogen) pressure from 700, 500, 350 or 200 bar (or 70, 50, 35 and 20 MPa) to operating pressure in addressing all safety and operational requirements.
  
  Section::::Applications.:Recreational vehicles.
   In the regulator device datasheets the line regulation is expressed as percent change in output with respect to change in input per volt of the output. Mathematically it is expressed as:
   Section::::Operation.:Mechanism.
  
  Diving regulators use mechanically operated valves. In most cases there is ambient pressure feedback to both first and second stage, except where this is avoided to allow constant mass flow through an orifice in a rebreather, which requires a constant upstream pressure.
  
  Section::::Types.
  
  Section::::Types.:Open circuit demand valve.
  