How to Install a Water Pressure Reducing Valve | This Old House

take a look at this and you've got plenty of pressure there you see a steady stream here but it looks like there's so much pressure behind this aerator which also has a flow restrictor in it it shooting out through the sides any time there's high water pressure we worry about valves and appliances they're really not designed for super high water pressure we also hear a complaint about water hammer those pipes banging yeah we have plenty of banging when we turn the water off you can hear a good thump that goes all through the house and top that off we've had garden hoses blow off the silcock outside just explode just explode i would say you do have high pressure why don't we run to the basement see what you've got coming into the building definitely that sounds good all right well let's see what you got here here is your main water supply to the building coming right in here this is the most important valve in the entire building this is the main shut off valve it's a ball valve which i like very much and to shut it off you turn this handle perpendicular to the pipe and you open it you put it in line with the pipe next is this this clamp is the ground the electrical ground any electrical system needs to have a proper ground so they tie onto here and use that metal pipe as the ground this is the water meter this is what reads how much water you used inside the building i'm glad to see this is the remote reader so they don't have to come inside your building to read it now to find out how much pressure you have i have to install this a pressure gauge now this can be installed on the outside faucet outside but there's a draw off here so we're very lucky i can do it right here now any house would love to see about 50 pounds of pressure and look at that you got what you've got double that you've got about 118 pounds of pressure i would say you do have high pressure definitely so the only thing we can do is to install a pressure reducing valve let me go get one to show you so here's your pressure reducing valve it's going to take the 118 pounds coming in from the street right here and adjust it down to about 50 pounds on this side there's an adjusting screw right here that we can set for any pressure we want on the downstream side i brought a cutaway to help understand what's going on inside here's that adjusting screw and underneath this cap is a spring so we're going to set that spring for about 50 pounds of tension what it's controlling is this piston has a little diaphragm right here and now you'll have the 118 on this side and the spring is going to be holding it so it opens and closes to deliver 50 pounds of pressure on the downstream side you'll spend its whole life going up and down doing whatever it has to do to always guarantee 50 pounds on this side all right so let's get this thing installed sounds good okay alright well so here is our pressure reducing valve and i've installed a pressure gauge on the inlet side and another pressure gauge on the outlet side so now we can see what's going on pressure wise on both sides of the valve i'd like to install it right here so i just want to mark the pipe right there and right there now before i cut it i need to shut the water off hold it up upstairs and now i just need to drain the water out of that pipe good now we need to solder these two connections right here before i do i've removed the two pressure gauges and there's a couple of o-rings up inside the valve that i want to be sure i removed just while i solder so i don't damage them once i've made this up i can flux the connections and we're ready to go a little flux on the pipe too now we just fit the connection together there's one with the pipes cooled i can reinstall my gauge i've already reinstalled the o-rings down here on the valve i'm going to tighten that up with an open end wrench and once we do that it's time to turn the water on good now i'm going to start by opening this valve and now the main water supply right here all right so what do we got got about 110 pounds right here and that comes from the city right right that's the city supply it goes through our pressure reducing valve and look at this we're about 50 pounds on this side now it was too high i could have turned this counterclockwise it would have made it a little bit lower if i want to increase it i could have turned it clockwise but 50 is perfect for house like you hey richard that's great you've really helped to solve our problem it's what we do

Channel: This Old House

Views: 752,818

Keywords: This Old House, Ask This Old House, DIY, Home Improvement, DIY Ideas, Renovation, Renovation Ideas, How To Fix, How To Install, How To Build, Pressure (Dimension), Valve, Water, water pressure Plumbing, Plumber, shower, Home Repair, Richard Trethewey, Cleaning, bathroom, Construction, plumbing 101, plumbing basics, plumbing tricks, house plumbing system, how to plumb a house

Id: xs2GXur9fPM

Length: 5min 21sec (321 seconds)

Published: Sat Oct 11 2014