P-Trap On Sink?

[bletso]

Should I install a p-trap on the sink. I am moving the discharge and it will have a straight discharge above the water line. The old location left a natural dip in the hose. A p-trap or drooping hose would prevent insect intrusion into the sink drain. Am I correct in assuming the need for one or the other?

[sailorchic34]

Originally Posted by bletso

Should I install a p-trap on the sink. I am moving the discharge and it will have a straight discharge above the water line. The old location left a natural dip in the hose. A p-trap or drooping hose would prevent insect intrusion into the sink drain. Am I correct in assuming the need for one or the other?

Assuming the sink drains overboard, no p-trap is required. If it connected to a grey water tank, then a p-trap would reduce odor in the boat, from the grey water tank.

The purpose of the p-trap in plumbing systems is to prevent odors from sewers from entering a house. On a boat sink, draining overboard, they are not needed.

[delmarrey]

Originally Posted by sailorchic34

Assuming the sink drains overboard, no p-trap is required. If it connected to a grey water tank, then a p-trap would reduce odor in the boat, from the grey water tank.

The purpose of the p-trap in plumbing systems is to prevent odors from sewers from entering a house. On a boat sink, draining overboard, they are not needed.

And here this whole time I thought a P-trap was to catch the wife's diamond ring when she dropped it down the drain.

[cal40john]

Read his original post carefully. Above waterline through hull, wants insect barrier.

Seems to me it would work if you have the vertical clearance

[MBWhite]

Originally Posted by delmarrey

And here this whole time I thought a P-trap was to catch the wife's diamond ring when she dropped it down the drain.

My thoughts exactly, the trap is the last barrier for recovery of irreplaceable or expensive bits. Whether it is a ring or you are disassembling a pump in the sink because it is too rough to do it on the table sometimes stuff goes down even when you are meaning to have the stopper in. If it keeps bugs out, that is another plus in my book.

[sailorchic34]

Sorry I was just quoting the engineering reason for a p-trap. On a power boat, sure it might keep bugs out. On a sail boat, heeled over, the p-trap will drain most if not all the water out and will not be filled till its used again. I would be only slightly worried of the stains from tooth paste, soap, etc staining the hull too.

Needless to say the p-trap came into existence, not to keep rings from going down the drain, but to keep methane from the sewers out of homes and businesses. Generally if you run water down the drain a ring would be flushed out of the trap anyway.

Bugs generally just come in the open hatches anyway. Least they do on my little boat.