Bird Screen on PSV outlet Required?

[advsign]

Is it required to install a bird screen (wire mesh to prevent bird next inside of PSV outlet pipe) on the outlet of the PSV discharge by any type of code?
Thanks,
Ken

 

[gerhardl]

I guess what you actually are asking is: 'who is going to pay for this extra, but obviously sensible added protection, not specified in the original contractual papers?'

Anyway, this will of course be depending on where you are in the world.

It might be defined put under general human safety rule, as a bird nest could obstruct the outlet capacity and give a dangerous situation.

I believe else that 'no' is the answer, the nearest comparison I can remember is the often general description of hygienic protection of water reservoirs openings against animal life.

 

[maddocks]

We have used bird screens, plastic bags, tennis balls, canvas covers, etc. I don't think it's a code issue although you could probably dig through the code to find you are not supposed to have any blockage of the outlet vent piping.....that's a hint for using a screen or bag of some type.....

 

[dcasto]

I like the bags they sell that are bright red and made to fit.

 

[advsign]

Does someone have an internet link or name of these bags?
I would like to at least require them to install these bags.
Thanks

 

[EGT01]

Try searching for pipe covers or weather caps. Also check with your local relief valve or rupture disk supplier. I'm sure they will be more than happy to assist.

http://www.oseco.com/pages/products/holders.html

http://www.zookdisk.com/disk_holder_accessories.asp

http://www.weathercap.com/weathercap.htm

 

[unclesyd]

Our site is bird sanctuary, + seagulls, and we have never used any covers over any relief valve vents. The only thing we require on the vents is a drain on any vent larger than 2" dia. But as stated above if you want an friable end cover there should be no harm. Nothing should ever be inserted in the vent.

 

[robsalv]

At our site, we've installed wire mesh baskets on the end of relatively large diameter discharge pipes - 12" diameter and larger.

The basket is a conical shape, topped by a "chinaman's hat" so that water doesn't pool. A metal ring at the base connects to the discharger pipe. A wider diameter ring connects to the "hat". 5 plate metal strips connect the two rings. Wire mesh is strung around the lot.

Someone calculated that a surface area of the cone/basket of >>twice that of the discharge pipe opening would be sufficient to ensure no effective obstruction to discharge relief path.

We would often find nests and dead birds inside the discharge pipe - but nothing ever big enough to obstruct a real SV lift.

Cheers

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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[CHD01]

Installing rain covers, bird screens are not prohibited by the Code. Drain or weep holes in the bottom of a discharge line that can collect water and build backpressure against the relief vavlve are required by the Code. The minimum weep hole size is 1/2-inch diameter.

The more you learn, the less you are certain of.

 

[jistre]

Day late and a dollar short, but I just have this vision of the unfortunate bird that builds a nest in a high pressure relief line that just gets LAUNCHED when the PSV pops.

This makes me giggle like a damned fool.

 

[4Pipes]

We have a similar question - very real but creating great amusement and no answers. Would a "crown" of 3/8" round bars welded welded around the outside of the exit?

The bars would not affect the flow but would stop birds perching. Say 6"-8" stand out above the exit and at 3" centres around the circumference. The stand out would need to be high enough to stop the birds scaffolding out for a nest by putting branches inbetween.

You could sharpen bars to to a point if you were really kean. A bit like the man traps built by the viet cong but up in the air rather than hidden in the ground.

Come to think, you could use the same design as for stern wheeler chimneys. I would not be surprised if those fancy chimney terminations had a practical use after the boilers had cooled down. Who says engineers can't be a creative. I am told the problem with sea birds is that they sit on such edges to eat their fish. They either tip over backwards when they swallow the fish or have problems with CofG combined with "nap after dinner" syndrome.

 

[CHD01]

Why are you concerned about the minimal probability of a bird sitting atop a discharge line. If they are there they will not be there long.

The more you learn, the less you are certain of.

 

[robsalv]

CHD01, we have some very low pressure relief valves with large diameter discharge piping. An obstruction in the relief path might not be cleared during a pop. It's more likely that a bird might nest IN the discharge pipe rather than on the opening of the discharge pipe - hence a screen/basket is not a bad idea.



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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."