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municipal water supply overpressure

Discussion in 'Irrigation' started by gusbuster, Sep 23, 2017.

  1. gusbuster

    gusbuster LawnSite Bronze Member
    Messages: 1,931

    Just kind of surprised by this one. Had 2 a.s.v. blow on the pressure side where male adapter screws in to valves within couple months of each other.

    The main reason i'm surprised was the reading i got. I had my client call the water purveyor and got a confirmation about my readings of 90 psi with a 13 plus gpm off of a 3/4 main line from the street water meter.

    What could the city have done that could of increased the volume and psi available?

    I would think that with those kind of readings when the house was built 40 years ago, they would of installed a water regulator after the main house shut off. None of the houses on that block and around the area can you see an obvious water regulator

    I know recently recently because most of the municipal water pipes are being replced( some are over 80 years old) with new pipes. Could pressure and volume increase that much.

    This city uses part of the Hetch Hetchy(san francisco water dept) water and some city wells.

    Im just wondering because i'm sure my client isn't the only one having overpressure problems. I know just the other day the neighbor had a joint come apart under her driveway(copper water line)

    Any thoughts?
     
    Mike Leary likes this.
  2. Mike Leary

    Mike Leary LawnSite Fanatic
    Messages: 23,158

    I've been in areas where they increased the lines and threw in PRVs upstream, which screwed me for installs. I complained, and they removed them. Increasing PSI without letting the clients know is typical purveyor mind set, stupid. You know what to do, but the client will not be happy, you know that, too! Good luck.
     
    SoCalLandscapeMgmt likes this.
  3. gusbuster

    gusbuster LawnSite Bronze Member
    Messages: 1,931

    I could install the regulator, but my c-27 won't let me do to the mainline for the house. Permits are going to be needed to be pulled and a plumber is going to have to install it. Sucks, as i told the client to raise hell.
     
    hort101 likes this.
  4. SoCalLandscapeMgmt

    SoCalLandscapeMgmt LawnSite Silver Member
    Messages: 2,144

    I too have seen purveyors increase system pressure for one reason or another. Can you just throw a PRV on the irrigation main and call it done? I would figure that you would want a separate PRV for the house and the irrigation system.
     
    Mike Leary and 1idejim like this.
  5. gusbuster

    gusbuster LawnSite Bronze Member
    Messages: 1,931

    First its an existing system that got put it. All the supply lines for the irrigation and pondless waterfall are all tied into each other and to be frank, i don't want to open another can of worms. The valves in question are in the back yard. the installer t'd off of water spigot right off the house, then went straight into concrete under a spa ect.....would be a pain. They also are having problems with the ice maker and dishwasher

    One of the first questions i asked the client after the second asv blew was have they been having problems with their ice maker or dishwasher.......response how did you know.

    So for them best course would be to have that regulator installed at the beginning of the house water supply.
     
  6. mitchgo

    mitchgo LawnSite Silver Member
    Messages: 2,946

    Unfortunately blaming others doesn't help much. A PRV is the best that can be done for your customer.

    Highest I've seen on a city municipal is 172 PSI.

    You have to take a step back and stop thinking about the end result of pressure at that house and think of the picture of the watering system as a whole.. Especially a city like San Fran

    There are miles and miles of plumbing that supplies water to households- In that are a various amount of pumps, pressure tanks, water towers . When you have many hills and super aged plumbing throughout an old city, Things need to get upgraded and fixed .

    As we all know the further water travels down a pipe the less available pressure is available at the end given the demand drawn, when water travels uphill the pressure is lost also with gravity. So you have to start high to have adequate end result.

    Now- Could a water system be designed in a way that all households are given the same, equal water pressure to each. Yes , of course it could- however what's the extra cost in that? 2x,5x,10x,100x?

    It's easier to start it with high pressure and regulate each house after. Even in the irrigation designing world that's a preferred method too.

    One thing I don't get is that they ALLOW high pressure at end user. IF that house has 172 PSI.. HEY.. That's up to the contractor and end user to ensure that pressure is reduced.
    What about Electrcity? Is it up to the house electrician to reduce the power usage from 1000amps ,100,000 volts? Is it up to the gas guy who installs your back patio natural gas grill to make sure the gas line is regulated properly?

    So why Is water so different?
     
    Big Al B likes this.
  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,592

    Water is different because pressure depends on elevation.
     
    Mike Leary likes this.
  8. SoCalLandscapeMgmt

    SoCalLandscapeMgmt LawnSite Silver Member
    Messages: 2,144

    Maybe the laws are different up there but I wouldn't think that a permit would be needed fora plumber to drop a regulator in right after the meter. Should be fairly straight forward and not too expensive.
     
    Srlance31 likes this.
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,592

    I would look to refit the supply plumbing first. Find a way to dump the male adapters in favor of sch 80 TOE nipples. Add a water hammer arrestor. Antisyphon (what make and model?) valves can take 90 psi supply pressures.
     
    Srlance31 likes this.
  10. gusbuster

    gusbuster LawnSite Bronze Member
    Messages: 1,931

    Its such a big difference between exile county and city of san fran and san mateo counties...Santa Clara county is not that bad but if you work in the city of San Jose, the municipal water code a joke.

    Technically, most of the cities I work in all require to pull a permit if you open up any kind of pipe (point of connection) and installing outdoor irrigation. first its always about money, second they just want to make sure that you are using n.s.f. rated pipe and using devices that are rated for potable water. I will be honest, i always assumed that what was sold at the irrigation houses was rated for potable water, but just the other day, i ran in to a box of globe valves that was stamped not for potable water.

    So with that said, I don't know the labor situation down south, but it's absolutely crazy up here. One of my workers i laid off during the drought landed on his feet at a construction job. What does he do? he holds a sign directing traffic at the construction site. His pay.......45 an hour.

    Hate all the goof balls in s.f., but love the money
     

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