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View Full Version : Flow Capacity of 1" Orbit and other Valves


Steve P
05-30-2012, 09:24 PM
I have a marginal system that I am trying to fix. Pressure is ample and there are not too many sprinklers, at least according to the tables I've seen. All the pipe is 1" heavy wall PVC.

The sytem has 1" Orbit Jar Top valves. These valve do NOT have as large an inside diameter (ID) as the 1" pipe. Thin or thick wall pipe matters not, the valves inlet and outlet ID are visibly smaller. This undersize ID at both the inlet and outlet must be creating an orifice and restricts flow. Stupid valve design.:nono:

Question: What valve brand (if any) has a flow capacity (same ID and flow annulus) the same as the 1" pipe? I only need to replace 6 valves, so cost is not much of an issue.

Thanks for loaning out your experience and expertise.

Wet_Boots
05-30-2012, 09:27 PM
You are much better off looking to modify zones to improve pressure and performance. For the record, a zone valve like an Orbit Watermaster is not very different than 'pro' one-inch zone valves.

FIMCO-MEISTER
05-30-2012, 09:29 PM
How many feet is the water traveling through that valve? A flow chart will give you the pressure loss and I doubt much will be gained by going to another 1" valve. This is not a defense of orbit just do the math before you put yourself through a useless effort.

Steve P
05-30-2012, 10:27 PM
I have 62 psig static pressure (no flow pressure) and the zone only has 4 Orbit Voyager II sprinklers. With size 8 nozzles in each sprinker, they are throwing 6 feet shorter than the Orbit table says they should. Each zone suffers pretty much the same lack of distance throw, so I don't think it's any one vave just not opening all the way.

Seems anemic to me.

Thanks for the advice.

Sprinkus
05-30-2012, 10:29 PM
Question: What valve brand (if any) has a flow capacity (same ID and flow annulus) the same as the 1" pipe?

Simple answer (http://www.irritrol.com/valves/valves_700s.html)

Correct answer: What everyone else said or will say.

S.O.Contracting
05-30-2012, 10:34 PM
I have 62 psig static pressure (no flow pressure) and the zone only has 4 Orbit Voyager II sprinklers. With size 8 nozzles in each sprinker, they are throwing 6 feet shorter than the Orbit table says they should. Each zone suffers pretty much the same lack of distance throw, so I don't think it's any one vave just not opening all the way.

Seems anemic to me.

Thanks for the advice.

Put smaller nozzles in. The 8 is approx 4 gpm. Your system probably can't supply that volume regardless of pressure. Shoot for 12 gpm or so. Sounds like bad design from the start.

Waterlogged
05-30-2012, 11:53 PM
How big is the meter? Is it open all the way ? Is there a master valve ? Are all gate valves open ? Read the meter when a zone is running how many GPM ? A #8 RainBird x 4 = 28 Hunter #8 red x 4 = 14.8 blue is more. I don't know about Orbit

Steve P
05-31-2012, 08:08 AM
How big is the meter? Is it open all the way ? Is there a master valve ? Are all gate valves open ? Read the meter when a zone is running how many GPM ? A #8 RainBird x 4 = 28 Hunter #8 red x 4 = 14.8 blue is more. I don't know about Orbit
Waterlogged:
1. 1"
2. yes.
3. Yes. 1" Ball Valve. 100% open.
4. No gates.
5. Good idea to check meter for actual gpm. I'll do it this weekend. thanks!

Steve P
05-31-2012, 08:10 AM
Simple answer (http://www.irritrol.com/valves/valves_700s.html)

Correct answer: What everyone else said or will say.
The Irritrol valve is exactly what I was looking for. But WOW! That's a pricey valve. Still, a choice to replace the Orbit junk and looks like a great valve.

Steve P
05-31-2012, 08:13 AM
I forgot to mention: this system has one of the prefab Orbit manifolds. It is the "old style" that they quit using in 2007 or 2008. The ID on it is also quit small. Actually looks like 3/4".

I can make a 1" manifold and will likely try that first.

I hate to think about a re-do on the whole system, but may have to be done.

Again, thanks for all the replies.

Kiril
05-31-2012, 08:34 AM
I have a marginal system that I am trying to fix. Pressure is ample and there are not too many sprinklers, at least according to the tables I've seen. All the pipe is 1" heavy wall PVC.

The sytem has 1" Orbit Jar Top valves. These valve do NOT have as large an inside diameter (ID) as the 1" pipe. Thin or thick wall pipe matters not, the valves inlet and outlet ID are visibly smaller. This undersize ID at both the inlet and outlet must be creating an orifice and restricts flow. Stupid valve design.:nono:

Question: What valve brand (if any) has a flow capacity (same ID and flow annulus) the same as the 1" pipe? I only need to replace 6 valves, so cost is not much of an issue.

Thanks for loaning out your experience and expertise.

The only way you are going to get a full bore valve is to get an actuated ball valve. Be prepared to drop some serious cash.

FIMCO-MEISTER
05-31-2012, 08:42 AM
Sounds like you are dieing to tear into that valve set up. You'll still have to renozzle some heads. May not even need to mess with the valves if just put the proper nozzles in for the head.

Wet_Boots
05-31-2012, 08:46 AM
Re-nozzle the heads on one zone before considering anything else.

Steve P
05-31-2012, 05:54 PM
You last 3 posters have 78,000 posts between you. I suppose you MIGHt know what you're talking about!

Yes, those actuated ball valves are a tad pricey! Ouch.

I'll toss in some smaller nozzles and see what I get. It will help cover more area, but certainly require more time per zone.

Yes, I really do have an itch to tear into that valve manifold and make it bigger. Lot of work though!

Thanks guys!

DanaMac
05-31-2012, 06:27 PM
I could be wrong, but I seriously doubt that replacing the valves or the prefab manifold set up is going to help that much. I really believe that it does need re-nozzzling of the heads.

But on the other hand, I personally would rip out anything that says Orbit, and replace it with better brand components - valves, manifold set up, heads, all of it. Orbit products do not last the test of time. If you are going to dig it up, yes replace it with something better. Rainbird, Hunter, Weathermatic, Irritrol valves. Rainbird or Hunter rotor heads. And get rid of the crap prefab mani set up. They are junk. They will leak soon enough.

Kiril
05-31-2012, 08:28 PM
Don't rip anything out until it warrants replacement. Without knowing your available max flow, the safe bet is you have exceeded it with your current nozzling, as most everyone here has noted.

bcg
05-31-2012, 08:39 PM
I'm pretty sure that the Orbit Jar Top is basically an Irritrol 2400 valve. I wouldn't mess with them until they fail. As others have said, you're zone is overnozzled, without knowing the pipe distances, safe design on 1" pipe should be around 12GPM. If you feel the need to replace something, I'd take the Orbit heads out (which are basically a rebranded PGP) and put in RainBird 5000 series heads with 3GPM nozzles. I'm assuming that these heads are all the same radius (ie all 1/4 or all 1/2). If not, you need to nozzle accordingly. For example in a zone with 4 heads, 2 of which are 1/4 and 2 of which are 1/2, put 2GPM nozzles in the 1/4 and 4GPM in the 1/2, still totals to 12GPM for the zone.

Mike Leary
05-31-2012, 09:00 PM
Now now, you're pushing too hard on design criteria. Simply using specs from the boiler plate without knowing what the feed is from the street/well is not going to do anyone any good. If you've got 7 gpm @ 45 pounds measured off the meter AFTER the backflow, so be it, design for it. Deal with it.