Need help identifying a part from my vent hose

[zinahewitt]

Hi All,

I am looking for a thru-hull
1 inch diameter
1/2 inch pipe
2 inch length
NPT

I can't handle anything bigger than 1" diameter.
It is to vent my waste sack.

If you have seen one, let me know.
If you know the terminology to find one online that would help too.

 

[kloudie1]

Not identical but could be used/something like this?
Groco Stainless Steel Thru-Hull Fittings
Boat Thru-Hull Fittings | West Marine

 

[BigEasy]

Not identical but could be used/something like this?

Claude,
I like the Groco stainless fitting. Install that & it’s good for a lifetime. The plastic fittings are too susceptible to UV degradation & breakage.

 

[Peggie Hall HeadMistress]

You can't upgrade your vent to 1" by just replacing the thru-hull. To do that requires either a new 1" vent fitting on the tank or an adapter in the current 5/8" line to upsize the vent line to 1". Thru-hull would no longer be a "vent" thru-hull because they're only available in 5/8". Instead you'd need a 1" open bulkhead (aka "mushroom") fitting--the same kind your bilge pumps use. It needs to be either metal (Perko has stainless steel or chrome plated).This provides two advantages: allow the tank to breathe--which is the key to preventing odor out the vent--and also prevent vent blockages by allowing you to put a hose nozzle against it on a regular basis to back flush the vent line. Anything trying to set up housekeeping in it will get a water slide ride into the tank.
What part are you trying to identify?

--Peggie

 

[zinahewitt]

You can't upgrade your vent to 1" by just replacing the thru-hull. To do that requires either a new 1" vent fitting on the tank or an adapter in the current 5/8" line to upsize the vent line to 1". Thru-hull would no longer be a "vent" thru-hull because they're only available in 5/8". Instead you'd need a 1" open bulkhead (aka "mushroom") fitting--the same kind your bilge pumps use. It needs to be either metal (Perko has stainless steel or chrome plated).This provides two advantages: allow the tank to breathe--which is the key to preventing odor out the vent--and also prevent vent blockages by allowing you to put a hose nozzle against it on a regular basis to back flush the vent line. Anything trying to set up housekeeping in it will get a water slide ride into the tank.
What part are you trying to identify?

--Peggie

Hello Peggie,
Hope your day is going well.
Loved your book, helped me re-do my plumbing and for my boat to no longer stink.

I have a new IMTRA Nauta 35.5.
It has a vent for the holding tank.
The vent is 5/8"s

The vent goes up the hose to a Barb to NPT 1/2"
the barb2NPT goes into a 1/2" knee
The knee attaches to the thruhull.

The thru-hull is what broke.
It is plastic and sun degraded it.
The "Diameter" of the mushroom on the outside of the boat is 1"
The pipe itself is 1/2" inch
the length is 2" inches.

I don't seem able to find any mushroom thru-hull that is 1" in diameter.
They all seem to be 1.5 inch or more.

So that is my issue, finding a thru-hull.
In the meantime I have ordered a regular one I could find which is 1.5" and will dremel it to make it fit
but obv won't be pretty.


Unrelated, any recommendation between the plastic and the metal ones ?

 

[Peggie Hall HeadMistress]

Use metal...Most of the plastic ones are nylon, which is not UV resistant. Sunlight--even just daylight --turns them into powder.

--Peggie

 

[Project_Mayhem]

Most marine pipe fittings will be straight thread, not NPT which is tapered. These should not be mixed

 

[zinahewitt]

Most marine pipe fittings will be straight thread, not NPT which is tapered. These should not be mixed

All the fittings I have on this vent are tapered
The vent
the knee
the barb

So I figure it is called NPT.

 

[Peggie Hall HeadMistress]

Most marine pipe fittings will be straight thread, not NPT which is tapered. These should not be mixed

Most sanitation fittings are NPT, which is why it's so important NOT to over-tighten tank and joker valve connections. Doing so will crack the female fitting in a tank or the discharge fitting on a toilet.

--Peggie

 

[Peggie Hall HeadMistress]

I don't seem able to find any mushroom thru-hull that is 1" in diameter. They all seem to be 1.5 inch or more.

You should be looking for a bulkhead fitting. However a 1/2" pipe won't fit a 1" thru-hull...you'd need to replace the vent line with a 1"...which isn't hard to do if you're handy with a hole saw bit on a power drill, thanks to gizmo called a uniseal. However you can improve the tank's ability to breathe quite a bit by just replacing the "vent" thru-hull (which is actually designed to keep sea water out of fuel and water tanks and totally inappropriate for a waste tank venting 'cuz it doesn't let the tank breathe...but boat builders use 'em for waste tanks too because it saves 'em a few pennies to use the same thru-hull on all vents) with a 5/8" metal bulkhead fitting. This not only lets the tank breathe, but it also prevents vent blockages by letting you put a hose nozzle against it to backflush the vent line on a regular basis...anything trying to set up housekeeping in it will get washed into the tank.

--Peggie

 

[zinahewitt]

You should be looking for a bulkhead fitting. However a 1/2" pipe won't fit a 1" thru-hull...you'd need to replace the vent line with a 1"...which isn't hard to do if you're handy with a hole saw bit on a power drill, thanks to gizmo called a uniseal. However you can improve the tank's ability to breathe quite a bit by just replacing the "vent" thru-hull (which is actually designed to keep sea water out of fuel and water tanks and totally inappropriate for a waste tank venting 'cuz it doesn't let the tank breathe...but boat builders use 'em for waste tanks too because it saves 'em a few pennies to use the same thru-hull on all vents) with a 5/8" metal bulkhead fitting. This not only lets the tank breathe, but it also prevents vent blockages by letting you put a hose nozzle against it to backflush the vent line on a regular basis...anything trying to set up housekeeping in it will get washed into the tank.

--Peggie

Hi Peggie,
Hope all is going well.
I put
Forespar Thru- Hull Connector 1/2",Series 251

https://www.forespar.com/pdf/techTips/906022-thru-hull-connector-chart-tech-tip.pdf

The outer circle on the outside was 1.5 inch and it fit.
The item was .8 inch width which fit my hole on the side of the boat.
and the inside is 1/2 inch.
This all went to a 5/8 hose
then to the FTPE300 vent which is on my Imtra Nauta flexible tank.

What you are saying is that 5/8 is not so great and I might as well replace it with a 1" vent line or more so I can vent the tank better ?


The hose nozzle backflush I already do that as it was in the book.

Thanks

 

[Peggie Hall HeadMistress]

What you are saying is that 5/8 is not so great and I might as well replace it with a 1" vent line or more so I can vent the tank better ?

Oxygen is the key to eliminating holding tank odor out the vent.... "vent" thru-hulls allow very little air exchange....just swapping it out for a bulkhead fitting improves it a lot but not nearly as much as a vent line that's twice the diameter of the standard 5/8" line--which btw is the same size used on water and fuel tank vents that don't need to breathe. Although a 1" vent would be best, you may be limited to a 5/8 vent line by the size of the vent fitting on your tank.

QUOTE="zinahewitt, post: 1854668, member: 161940"]The outer circle on the outside was 1.5 inch and it fit.
The item was .8 inch width which fit my hole on the side of the boat.and the inside is 1/2 inch.[/QUOTE]

You're only concerned about the size of the hose that connects to the thru-hull and whether the "pipe" on the thru-hull is the correct size for the vent line. The outside diameter of the part of the thru-hull that's outside the hull is irrelevant.


--Peggie