Master Valve with poly main, or just a poly main?

[rvsuper]

If you guys use poly mainlines, do you use a master valve also so there isn't always pressure at the poly main, or do you just have constant pressure on the poly main? I always use PVC, and this question was just out of curiosity. I would think that a poly mainline would be able to hold constant pressure?

Any comments?

[greenworldh20]

always use master valve with poly main...poly doesnt hold pressure as well as pvc.

just my .02

[rvsuper]

Brain,
Have you seen systems with a poly main without a master valve?

[JeffY]

I'll always use a master valve when using a poly main. Although I have not seen one for myself, I've heard few stories in the local area about poly main pipes bursting without master vavles. They would fix it and it would burst again in another area.

[rvsuper]

Jeff,

At what pressure would it start bursting? I am just curious because I have never used a poly mainline before, all PVC.

[DanaMac]

I've done the poly mainline with no MV and have had no probs. But you have to get the higher rated poly. They make a poly for mainline applications.

[JeffY]

We use the Eagle poly (PE 3408)that's rated at 100 psi, but there are two other Eagle types the PE 2406 and PE3408 (note the difference..no space) that are rated up to 80 psi. It's quite possible that these companies were running into the lower type pipes on the commerical properties that were causing the pipes to burst.

[turfman59]

I cant beleive my eyes.

poly doesnt hold pressure so you need a master valve.

I have worked on systems that have been in the ground for 20 years and longer with no master valve, with no probs. I think that the potential burst problems would be with the fittings not the pipe. Just my 3 cents worth, here at aqua turf we always give you more

[greenworldh20]

i have seen many main lines burst....they were poly mains...just my.o2

[rvsuper]

I can't believe this! How much pressure are laying in those mainlines that make them burst??? Was it under the 100 psi rating??? The highest pressure here that I deal with is about 50 psi, will that cause them to burst?? Fill me in about this, I'm just curious on how these poly mains do.

Alex.

[turfman59]

Originally posted by greenworldh20
i have seen many main lines burst....they were poly mains...just my.o2 where are they bursting, Have they been trenched in or pulled in with a cable plow. Is the actual pipe splitting down the side or is this from a sharp object.

[HBFOXJr]

I think that in a lot of the country poly is used from wells to houses and barns under pressure 24/7. Do we see them bursting? I think not.

[rvsuper]

Harold has a good point. My city main in my basement is poly.

[DanaMac]

Very good point. I have also seen many homes with wells having the supply line to the home with poly. I actually installed some for a home I helped build in '97.

[Arnold]

I have not seen poly mains burst or leak. But the chance is there if you are worried about it put in a master valve. I have seen poly lines burst, but I believe most of them were from a slite freeze from improper winterization or a low spot in the line. Stress poly and its going to burst sooner or later.

[All American Lawn]

Thin wall poly rated at 100 psi what we call thick wall is rated at 160psi......the pvc that we use is thin wall rated at 100psi.......poly will give more than pvc as far as freezing goes....pvc will not give at all.....im sure you guys already know this...