SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

You should figure this stuff out before you order the equipment. Your pump has a performance curve, which you can read, and then see how many impact heads can be run at one time. (If you have wedge-drive impacts, you might run over a hundred of them simultaneously from a five horse pump)

Speaking of burned-out pumps, you need some mechanical safeguards, like a pressure relief valve that can blow off the pump output, in case there's a stuck valve or a blockage.

I agree with BOOTS about the pump, you definitely need to look up the manufacturer and model number to find out the performance curve. However, I am not a big fan of pump start relays or pressure relief valves. I recommend a product called "Cycle Stop Valves" ( here is a link www.cyclestopvalves.com/index2.htm ), as you will see these valve will deliver constant pressure at variable flow rates. They can be expensive depending on the model, but as I have seen in many cases, they are well worth it. To explain the reasons for my dislike in the psr (pump start relays) they are noisy for one (especially in humid areas or climates) and in most cases with larger pumps, such as yours, they will often fail. Although Hunter makes a quality product, they do not make the relay, they only manufacture the box they install it in. As for the pressure releif, they are sometimes difficult to adjust, what I mean is, you don't often have all the exact same amount of heads and pressure on each zone. Since they are pressure activated, you may have it blowing off excess pressure on one zone and not another. Most people may not agree with me on this, but I would only consider a pressure relief valve if there was only one zone. I have been working with pumps for the last 17 years, and I mean no disrespect to the other members of this forum, but I feel that the cycle stop valve are the only way to go.

As for your choice of valves, if the water is "dirty" or contain amounts of pond scum or algae, I would recommend a scubber valve instead of the standard. This will prevent you from having to clean, replace, or repair your valves after a period of time because of debris being caught in the valve ports (examples of this valve www.rainbird.com/landscape/products/valves/pesb_series.htm or www.hunterindustries.com/Products/Valves/icvfsintro.html ). I would also recommend filtration, such as disc filters, or your standard element filters (only for the irrigation around your house, due to the small spray nozzles you will need to accomidate this task). All of your impact heads should be unaffected by this dirty water.

I also wondered what you were using for an intake screen on your pump, or what you are at least considering? I would recommend a product called Sure Flo self cleaning screen. This screen will continuously clean itself from debris and algae as the system runs. It will most definitely beat taking a swim every few months to clean the alternatives. (here is a link www.sure-flo.com/catalog/pages/SCS_Pg4.htm )

I hope what I have recommended is of some help to you. I wish you the best of luck on you task an only ask for some blueberry cobbler when you are done..... Ha Ha

A 5 HP pump might be able to push as much as 200 gpm, so you need to pipe things to handle such flows. As long as you can run at pressures well below a relief valve's set point, it shouldn't be an issue. Another safeguard is a 'flow detector' switch, like those used in fire sprinkler systems. One of those would provide safety for the pump, in the event that there is no flow in the system.

Dirty water valves are the way to go, if you do split this up into zones. I would exchange the Hunter valves for Rainbird PESB valves. But first, you want to determine the capacity of the pump. There is a "four inch drop" method for measuring flow from the end of a level pipe. You really want to have some gpm and psi numbers to work with, before you go much further.

Another thing to consider, is how much protection you want to provide the pump motor. A relay to turn it on and off is just a start. There are motor control boxes for three phase motors. Maybe you already have one. Some of them have magnetic starters for the pump motor.

By the way, for those who might be wondering, a 'wedge drive' impact head is one which has a special impact arm, to allow positive full-circle operation with smaller-than-usual nozzles.

Agricultural irrigation is a different animal than residential lawn sprinkling. The cost of operation comes into play, which is why you sometimes see oversized piping laid above ground for ag irrigation.

Another ag item is the 'water reel' sprinkler, where a giant water-powered reel winds up the poly pipe that feeds it, while the giant impact head on the reel shoots a hundred feet or more.

By the way, I would tend to leave the existing one-zone lawn sprinkler system alone. Impact heads do better with dirty water than anything else.

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by cookgraygoose</i>I have sent emails out trying to find out more information on the pump as you suggested. It is old and I don't know if the company archives will show up the information requested or not but I am hoping to hear something from them.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">You want to measure actual pump performance, since you might have a worn, underperforming pump. Here's a page about using a ruler to measure the drop from the end of an open pipe, and matching it to a table, to get a flow rate
http://extension.oregonstate.edu/catalog/html/ec/ec1369/

As for reworking the lawn sprinklers, you'd probably be happiest with Maxipaw impact heads, if you have to run on dirty water. Not the first choice for clean city water, but very good for pumped pond water, on the lower pressures from pumps.