Holding tank exhaust on a 1989 silverton

NYCAP123 · 08-07-2009, 11:50 AM

Quote:

Originally Posted by chesapeake46

That quote made me laugh out loud.
It proves that you are kind at heart..........

When I was in Georgetown earlier this year a small cat with 4 guys on board transporting came in a bit past overfull. You would not believe how far the S... flew when that cap came off. Think Old Faithful. Yuk.

Capt J · 08-07-2009, 12:20 PM

Quote:

Originally Posted by NYCAP123

When I was in Georgetown earlier this year a small cat with 4 guys on board transporting came in a bit past overfull. You would not believe how far the S... flew when that cap came off. Think Old Faithful. Yuk.

One time I saw it shoot out like a guyser as wide as the opening and it shot up 8-10 feet higher then the deck and went all over everyone standing around (including myself who was not on the boat but just bs'ing with the owner because I knew him). It was the most disgusting thing I've ever experienced.

chesapeake46 · 08-07-2009, 12:28 PM

This was also in Georgetown, Md.
A freind of mine was trying to pump out his tank.
Nothing was happening.
Another friend on the pier said to him" have a look in there & see if it's clogged......"
It wern't.
The geyser errupted.
He was coated head to toe.
He turned and walked right off the pier into the river.
The rest of the week end the guys kept telling him he a piece of corn in his teeth.....

NYCAP123 · 08-07-2009, 12:28 PM

Quote:

Originally Posted by Capt J

One time I saw it shoot out like a guyser as wide as the opening and it shot up 8-10 feet higher then the deck and went all over everyone standing around (including myself who was not on the boat but just bs'ing with the owner because I knew him). It was the most disgusting thing I've ever experienced.

And how long did it take for you to live down the name of "S---head"?

I hope the owner bought you dinner (after a CLEAN shower).

61c40 · 08-07-2009, 10:01 PM

A 24x24 by however deep tank has a 576 square inch surface area using nothing more than a old handpump style joker valve weighted flapper seal assembly, it is possible to pressurize the tank with a plugged vent to a CATASTROPHIC condition with very little effort ,1/2 PSI on top equals over 250 at the 1 1/2 drop tube opening that is connected to the deck fitting!

crap happens

K1W1 · 08-08-2009, 05:33 AM

Quote:

Originally Posted by 61c40

A 24x24 by however deep tank has a 576 square inch surface area using nothing more than a old handpump style joker valve weighted flapper seal assembly, it is possible to pressurize the tank with a plugged vent to a CATASTROPHIC condition with very little effort ,1/2 PSI on top equals over 250 at the 1 1/2 drop tube opening that is connected to the deck fitting!

crap happens

Hi,

You mght want to check your maths here F = P x A, if you change the value of either P or A the F number will also alter, if you had 250 psi at the outlet you would also have 250 psi at the tank top and wouldn't likely have a tank top still attached to the tank sides.

When pressure testing tanks it is well known that a 3m x 50mm tube full of water,exerts the same pressure on the tank top as a 3m x 100mm tube full of water.( mWc)

61c40 · 08-08-2009, 10:49 AM

I didn't have a calculator handy so my math was in my head . The pressure /force that I was referring to would be at the surface of the drop tube, and minus any weight of the drop tube effluent column height. It seems that every time I make a comment or obsevation you (kiwi )feel obligated to correct me and its not just me you seem to lurk to jump on anyone who posts anything that you can argue about. In the real world , I tell people like you to blowme

Marmot · 08-08-2009, 11:41 AM

Quote:

Originally Posted by 61c40

The pressure /force that I was referring to would be at the surface of the drop tube, and minus any weight of the drop tube effluent column height.

That is some odd math.

Quote:

Originally Posted by 61c40

In the real world , I tell people like you to blowme

I think there are better places to solicit such acts. But, putting your orientation aside for the moment, why would you want to become so intimate with someone you obviously don't like?

K1W1 · 08-08-2009, 12:24 PM

Quote:

Originally Posted by 61c40

It seems that every time I make a comment or obsevation you (kiwi )feel obligated to correct me .........

Hi,

I am sorry that you feel that somehow I have singled you out for some special correction, I had a quick look back at most of your previous posts here on YF to see where this was and did not see anything where I directly corrected or argued with your posts except here.

I also took a look at your public profile and was surprised to read that you say you are a Marine Engineer with 40 yrs experience who works as a consultant.

Someone who professes to be a Marine Engineer with that much experience and skill to now be called a Consultant should surely have some residual grey matter to keep the maths in his head company.

To get anywhere near 250 psi on your tank top you would have to have the effluent approx 550 ft up the vent line, that is some high mast (assuming your ventline goes up there)

If you are happy to give people you consult for mis leading information such as you posted here I feel sorry for your customers.

As for your closing statement, I am not that way inclined so you would not get the sort of response you expected should you say it to my face in the real world.

Capt J · 08-08-2009, 04:29 PM

Not be interrupt, but can everyone just stay on subject, calm down, and refrain from all of these political diatribes against each other.

I am no engineer, but I can tell you this much. If a waste tank has 250 psi of pressure in it, it would blow the tank to pieces.

K1W1 · 08-08-2009, 04:35 PM

Quote:

Originally Posted by Capt J

I am no engineer, but I can tell you this much. If a waste tank has 250 psi of pressure in it, it would blow the tank to pieces.

Hi,

That's a given.

This is what I wrote in post 21.

......if you had 250 psi at the outlet you would also have 250 psi at the tank top and wouldn't likely have a tank top still attached to the tank sides.

NYCAP123 · 08-08-2009, 08:38 PM

Numbers are very specific. Anybody who quotes them incorrectly and thinks it will not be challenged hasn't followed this forum closely enough. For some reason this weekend seems to be starting cranky. Must be a full moon.

sbmar · 08-09-2009, 10:32 AM

Wow !! I can see you guys take no prisoners---So I'd better be careful here..

Maybe what our "250 guy" meant was similar to having 500 sq inches of surface area in an enclosed container, add 1/2 PSI to the enclosure, and then you would have about 250 lbs pressing evenly on all surfaces--But it's still 1/2 lb per square inch................???????????????????????????

Anyway, that's the basic princple to why a lift muffler can work so well and lift water up a smaller pipe with a minimum of pressure--It's trading a large surface area at low pressure for the velocity of the gases and water with the result being able to lift a water column much higher than the engine normally could without exceeding back pressure limits.. In a well designed lift muffler, it's typical to see 3/4 PSI lift water 3-4 ft ................Yes I know, a totally different subject but thought the analogy may help save our friend from being hung out to dry. ..

Tony

61c40 · 08-09-2009, 11:29 AM

Thanks for the help sbmar, my reasoning is that I have used the application of low pressure air to pump 9 different gray ,holding and ballast tanks over the last 20 years thousands of times. I'll leave the math to the flightless bird and the small woodchuck. I'll bet that a 2psi positive air pressure on top of a tank thru the vent with a valve to control the inlet will discharge thru the drop pipe faster than a 2hp diaphram pump can pump it out.

61c40 · 08-09-2009, 11:36 AM

I forgot to add that its the same princpal as a super soaker water toy