Conversation with Griswold Controls

Discussion in 'Irrigation' started by FIMCO-MEISTER, Oct 20, 2010.

  1. i spent 45 minutes with a very nice 40 year veteran in our industry who walked me through how the Griswold is able to avoid the last 20% closing problem. So I am satisfied beyond any doubt that the Griswold belongs in its own category. No other valve is built like it which is about 99% of those in use is my guess. For them the 20% closing problem still exists as well as opening surge pressure from poor valve location and installation. He also said MVs don't eliminate surge pressures which is why the top designers use N.O. no surge anticipation valves connected to a flow sensor. (model 2265)
    So if you have water hammers and don't want to correct the real problems causing them then just toss in a Griswold MV with a new controller that has a zone delay feature. (I'm aware of zone delay controllers. I mentioned unless you have a controller that allows for a delay.) As for Leary opening the MV before turning on any zones doesn't seem too wise to me. You want a zone open with the MV opening or use a NO and leave the mainline charged at all times.

    NOTE THE SECOND SPRING. (29) That combined with the metering pin is the key.

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  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,482

    I don't think that "second spring" is the key, since it is supposed to provide a drain option of some sort, and the valves I've serviced did not have that spring. The 2000 does have a unique metering pin, though.
     
  3. It is complicated. The metering pin and the pin bearing and the way it is grooved. Always self cleaning. The spring plays a role. Not like any valve I've dealt with. Almost comes across as a valve within a valve. Here is the parts list that correspond to the diagram.

    F-800_5_2010.jpg
     
  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,482

    Your parts list identifies the part #29 as being in the "cold weather valve" ~ what it does is slightly open the de-pressurized valve by lifting the diaphragm assembly, and allowing drainage. Kind of a relic from the days of trenching a system and pitching the pipes to drain back to the source. No question that the valve could handle cruddy pond water, in the systems I worked with.
     
  5. Well you are the man to figure it out. Lot of friggin parts to make it do what they want it to do. Interestingly enough in the troubleshooting section when the valve quits shutting slowly time to replace the diaphragms.
     
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,482

    In the end, it's still a diaphragm valve, and the diaphragm material wasn't much (if any) different than what a common Richdel valve had.
     
  7. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,611

    Why? Since pros have been using the programmable fill delay forever without any problems, I find your comment ludicrous, at best. Most of our RM systems have NO valves, not for your unexplained reason :)dizzy:), but because those systems have quick-couple lines as well as zone valves. I have had problem zero with NC and NO master valves. It goes back to a proper design from the git, not some stupid ass head scratching re-do. :hammerhead:
     
    Last edited: Oct 20, 2010
  8. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,611

    Just had a thought, Peter. How many clocks can use a N.O. master valve and shut down should there be a line break?
     
  9. SoCalLandscapeMgmt

    SoCalLandscapeMgmt LawnSite Bronze Member
    Posts: 1,701

    You can do it fairly easy on just about any controller with a Data Industrial Model 330-04 Relay Transmitter and an impeller type flow meter
     
  10. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,482

    Here's a thought - how many of you warm-weather pikers have ever seen an all-copper-and-brass system that drained back to a valve in the basement?
     

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