Stus-List Re: vented loops

[Korbey Hunt via CnC-List]

Good to do an acid soak every few years.

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From: CHARLES SCHEAFFER via CnC-List 
Sent: Wednesday, June 29, 2022 2:19:34 PM
To: CNC boat owners, cnc-list 
Cc: CHARLES SCHEAFFER 
Subject: Stus-List vented loops

Learned the hard way how to test vented loops.

I was changing engine hoses and came upon an original, 33 year old, bronze, 
vented loop for the engine cooling water.  It's located between the heat 
exchanger and the injection elbow of the exhaust riser.  It's purpose is to 
break a siphon and prevent water flooding the engine and the boat when the 
engine is off.  Mine was filled with scale and no longer operational.

The following comes from info included with a new Forespar vented loop.  To 
test a vented loop, you blow air through the vent from outside into the tubing, 
through the "duck bill" rubber thing, and that's it.  If air won't penetrate, 
it's clogged and should be cleaned.  If the thing leaks, it probably needs 
cleaning or a new rubber duck bill.

I replaced the Forespar rubber duckbill, $15, on my bilge pump hose and I 
replaced the entire loop fitting $44 on the engine hose using a Forespar 5/8" 
vented loop.  Now both of my vented loops use the same duckbill vent and have 
the same size retaining nut so a simple clear two foot length of 3/4" hose can 
be pushed over the fitting to facilitate testing either vented loop.

I have to add that I never had a problem in twenty years of ownership and 
ingnored these items until I started replacing hoses.  I'd be glad to hear 
anyone else's ideas on this.

Chuck S

Stus-List Re: vented loops

[CHARLES SCHEAFFER via CnC-List]

Agree,  The point of discussing this topic is to learn and share maintenance 
methods with fellow C owners so they can avoid future problems.

Vented loops are little understood, but simple and easy to maintain.  I'll bet 
the majority out there are closed shut with salt crystals or scale.  Both of 
mine were.

Chuck S

> On 06/30/2022 12:27 PM Chris Riedinger via CnC-List 
>  wrote:
> 
> 
> Many folks don't have a problem with anything and thus don't change 
> anything. 
> 
> The real problem arises if you have a crack or leak beyond the failed 
> vented loop and you're below the waterline, away from the boat for extended 
> periods of time, etc
> 
> 
> Normal operation of items in service beyond vented loops have intentional 
> limits on the seawater entry. 
> 
> On Thu, Jun 30, 2022, 8:17 AM Dennis C. via CnC-List 
> mailto:cnc-list@cnc-list.com > wrote:
> 
> > > John,
> > 
> > Here's a pic of the vented wet exhaust riser on Touche'.  At least 
> > I think that's what it is.
> > 
> > 
> > https://drive.google.com/file/d/1r-3xSbChZeio35MrFSmtN03y6VW6ugKz/view?usp=sharing
> > 
> > It's the fiberglass loop at the top.  Don't ask me how it works.  
> > Don't ask me about the loop at the other end of the little gray hose, 
> > either.  I'm completely ignorant of this configuration.
> > --
> > Dennis C.
> > Touche' 35-1 #83
> > Mandeville, LA
> > 
> > On Thu, Jun 30, 2022 at 9:46 AM John Read via CnC-List 
> > mailto:cnc-list@cnc-list.com > wrote:
> > 
> > > > > 
> > > Interesting – have not heard or seen vented loops used this 
> > > way.  My 34 does not have them and no problems in 40 years
> > > 
> > >  
> > > 
> > > John Read
> > > 
> > > Legacy III
> > > 
> > > 1982 C 34
> > > 
> > > Noank, CT
> > > 
> > >  
> > > 
> > > From: CHARLES SCHEAFFER via CnC-List 
> > > [mailto:cnc-list@cnc-list.com mailto:cnc-list@cnc-list.com ]
> > > Sent: Wednesday, June 29, 2022 5:20 PM
> > > To: CNC boat owners, cnc-list
> > > Cc: CHARLES SCHEAFFER
> > > Subject: Stus-List vented loops
> > > 
> > >  
> > > 
> > > Learned the hard way how to test vented loops.
> > > 
> > >  
> > > 
> > > I was changing engine hoses and came upon an original, 33 
> > > year old, bronze, vented loop for the engine cooling water.  It's located 
> > > between the heat exchanger and the injection elbow of the exhaust riser.  
> > > It's purpose is to break a siphon and prevent water flooding the engine 
> > > and the boat when the engine is off.  Mine was filled with scale and no 
> > > longer operational. 
> > > 
> > >  
> > > 
> > > The following comes from info included with a new Forespar 
> > > vented loop.  To test a vented loop, you blow air through the vent from 
> > > outside into the tubing, through the "duck bill" rubber thing, and that's 
> > > it.  If air won't penetrate, it's clogged and should be cleaned.  If the 
> > > thing leaks, it probably needs cleaning or a new rubber duck bill.
> > > 
> > >  
> > > 
> > > I replaced the Forespar rubber duckbill, $15, on my bilge 
> > > pump hose and I replaced the entire loop fitting $44 on the engine hose 
> > > using a Forespar 5/8" vented loop.  Now both of my vented loops use the 
> > > same duckbill vent and have the same size retaining nut so a simple clear 
> > > two foot length of 3/4" hose can be pushed over the fitting to facilitate 
> > > testing either vented loop.
> > > 
> > >  
> > > 
> > > I have to add that I never had a problem in twenty years of 
> > > ownership and ingnored these items until I started replacing hoses.  I'd 
> > > be glad to hear anyone else's ideas on this.
> > > 
> > >  
> > > 
> > > Chuck S
> > > 
> > >  
> > > 
> > >  
> > > 
> > >  
> > > 
> > > > > 
> > 
> > 
> > 
> > > 

Stus-List Re: vented loops

[CHARLES SCHEAFFER via CnC-List]

Dennis,
Your picture shows two vented loops, vented into each other.  Possibly an 
engine cooling line and a bilge pump.  I'm no expert but I'm not sure if that 
is proper.  It could cause a problem if a vent valve fails open.

This Forespar video explains how they work.
https://www.youtube.com/watch?v=llT3VAAMsDE

Chuck S

> On 06/30/2022 11:15 AM Dennis C. via CnC-List  
> wrote:
> 
> 
> John,
> 
> Here's a pic of the vented wet exhaust riser on Touche'.  At least I 
> think that's what it is.
> 
> 
> https://drive.google.com/file/d/1r-3xSbChZeio35MrFSmtN03y6VW6ugKz/view?usp=sharing
> 
> It's the fiberglass loop at the top.  Don't ask me how it works.  Don't 
> ask me about the loop at the other end of the little gray hose, either.  I'm 
> completely ignorant of this configuration.
> --
> Dennis C.
> Touche' 35-1 #83
> Mandeville, LA
> 
> On Thu, Jun 30, 2022 at 9:46 AM John Read via CnC-List 
> mailto:cnc-list@cnc-list.com > wrote:
> 
> > > 
> > Interesting – have not heard or seen vented loops used this way.  
> > My 34 does not have them and no problems in 40 years
> > 
> >  
> > 
> > John Read
> > 
> > Legacy III
> > 
> > 1982 C 34
> > 
> > Noank, CT
> > 
> >  
> > 
> > From: CHARLES SCHEAFFER via CnC-List [mailto:cnc-list@cnc-list.com 
> > mailto:cnc-list@cnc-list.com ]
> > Sent: Wednesday, June 29, 2022 5:20 PM
> > To: CNC boat owners, cnc-list
> > Cc: CHARLES SCHEAFFER
> > Subject: Stus-List vented loops
> > 
> >  
> > 
> > Learned the hard way how to test vented loops.
> > 
> >  
> > 
> > I was changing engine hoses and came upon an original, 33 year old, 
> > bronze, vented loop for the engine cooling water.  It's located between the 
> > heat exchanger and the injection elbow of the exhaust riser.  It's purpose 
> > is to break a siphon and prevent water flooding the engine and the boat 
> > when the engine is off.  Mine was filled with scale and no longer 
> > operational. 
> > 
> >  
> > 
> > The following comes from info included with a new Forespar vented 
> > loop.  To test a vented loop, you blow air through the vent from outside 
> > into the tubing, through the "duck bill" rubber thing, and that's it.  If 
> > air won't penetrate, it's clogged and should be cleaned.  If the thing 
> > leaks, it probably needs cleaning or a new rubber duck bill.
> > 
> >  
> > 
> > I replaced the Forespar rubber duckbill, $15, on my bilge pump hose 
> > and I replaced the entire loop fitting $44 on the engine hose using a 
> > Forespar 5/8" vented loop.  Now both of my vented loops use the same 
> > duckbill vent and have the same size retaining nut so a simple clear two 
> > foot length of 3/4" hose can be pushed over the fitting to facilitate 
> > testing either vented loop.
> > 
> >  
> > 
> > I have to add that I never had a problem in twenty years of 
> > ownership and ingnored these items until I started replacing hoses.  I'd be 
> > glad to hear anyone else's ideas on this.
> > 
> >  
> > 
> > Chuck S
> > 
> >  
> > 
> >  
> > 
> >  
> > 
> > > 
> 
> 
> 

Stus-List Re: vented loops

[Chris Riedinger via CnC-List]

Many folks don't have a problem with anything and thus don't
change anything.

The real problem arises if you have a crack or leak beyond the failed
vented loop and you're below the waterline, away from the boat for
extended periods of time, etc


Normal operation of items in service beyond vented loops have intentional
limits on the seawater entry.

On Thu, Jun 30, 2022, 8:17 AM Dennis C. via CnC-List 
wrote:

> John,
>
> Here's a pic of the vented wet exhaust riser on Touche'.  At least I think
> that's what it is.
>
>
> https://drive.google.com/file/d/1r-3xSbChZeio35MrFSmtN03y6VW6ugKz/view?usp=sharing
>
> It's the fiberglass loop at the top.  Don't ask me how it works.  Don't
> ask me about the loop at the other end of the little gray hose, either.
> I'm completely ignorant of this configuration.
> --
> Dennis C.
> Touche' 35-1 #83
> Mandeville, LA
>
> On Thu, Jun 30, 2022 at 9:46 AM John Read via CnC-List <
> cnc-list@cnc-list.com> wrote:
>
>> Interesting – have not heard or seen vented loops used this way.  My 34
>> does not have them and no problems in 40 years
>>
>>
>>
>> John Read
>>
>> Legacy III
>>
>> 1982 C 34
>>
>> Noank, CT
>>
>>
>>
>> *From:* CHARLES SCHEAFFER via CnC-List [mailto:cnc-list@cnc-list.com]
>> *Sent:* Wednesday, June 29, 2022 5:20 PM
>> *To:* CNC boat owners, cnc-list
>> *Cc:* CHARLES SCHEAFFER
>> *Subject:* Stus-List vented loops
>>
>>
>>
>> Learned the hard way how to test vented loops.
>>
>>
>>
>> I was changing engine hoses and came upon an original, 33 year old,
>> bronze, vented loop for the engine cooling water.  It's located between the
>> heat exchanger and the injection elbow of the exhaust riser.  It's purpose
>> is to break a siphon and prevent water flooding the engine and the boat
>> when the engine is off.  Mine was filled with scale and no longer
>> operational.
>>
>>
>>
>> The following comes from info included with a new Forespar vented loop.
>> To test a vented loop, you blow air through the vent from outside into the
>> tubing, through the "duck bill" rubber thing, and that's it.  If air won't
>> penetrate, it's clogged and should be cleaned.  If the thing leaks, it
>> probably needs cleaning or a new rubber duck bill.
>>
>>
>>
>> I replaced the Forespar rubber duckbill, $15, on my bilge pump hose and I
>> replaced the entire loop fitting $44 on the engine hose using a Forespar
>> 5/8" vented loop.  Now both of my vented loops use the same duckbill vent
>> and have the same size retaining nut so a simple clear two foot length of
>> 3/4" hose can be pushed over the fitting to facilitate testing either
>> vented loop.
>>
>>
>>
>> I have to add that I never had a problem in twenty years of ownership and
>> ingnored these items until I started replacing hoses.  I'd be glad to hear
>> anyone else's ideas on this.
>>
>>
>>
>> Chuck S
>>
>>
>>
>>
>>
>>
>>
>
>
>
>

Stus-List Re: vented loops

[Dennis C. via CnC-List]

John,

Here's a pic of the vented wet exhaust riser on Touche'.  At least I think
that's what it is.

https://drive.google.com/file/d/1r-3xSbChZeio35MrFSmtN03y6VW6ugKz/view?usp=sharing

It's the fiberglass loop at the top.  Don't ask me how it works.  Don't ask
me about the loop at the other end of the little gray hose, either.  I'm
completely ignorant of this configuration.
--
Dennis C.
Touche' 35-1 #83
Mandeville, LA

On Thu, Jun 30, 2022 at 9:46 AM John Read via CnC-List <
cnc-list@cnc-list.com> wrote:

> Interesting – have not heard or seen vented loops used this way.  My 34
> does not have them and no problems in 40 years
>
>
>
> John Read
>
> Legacy III
>
> 1982 C 34
>
> Noank, CT
>
>
>
> *From:* CHARLES SCHEAFFER via CnC-List [mailto:cnc-list@cnc-list.com]
> *Sent:* Wednesday, June 29, 2022 5:20 PM
> *To:* CNC boat owners, cnc-list
> *Cc:* CHARLES SCHEAFFER
> *Subject:* Stus-List vented loops
>
>
>
> Learned the hard way how to test vented loops.
>
>
>
> I was changing engine hoses and came upon an original, 33 year old,
> bronze, vented loop for the engine cooling water.  It's located between the
> heat exchanger and the injection elbow of the exhaust riser.  It's purpose
> is to break a siphon and prevent water flooding the engine and the boat
> when the engine is off.  Mine was filled with scale and no longer
> operational.
>
>
>
> The following comes from info included with a new Forespar vented loop.
> To test a vented loop, you blow air through the vent from outside into the
> tubing, through the "duck bill" rubber thing, and that's it.  If air won't
> penetrate, it's clogged and should be cleaned.  If the thing leaks, it
> probably needs cleaning or a new rubber duck bill.
>
>
>
> I replaced the Forespar rubber duckbill, $15, on my bilge pump hose and I
> replaced the entire loop fitting $44 on the engine hose using a Forespar
> 5/8" vented loop.  Now both of my vented loops use the same duckbill vent
> and have the same size retaining nut so a simple clear two foot length of
> 3/4" hose can be pushed over the fitting to facilitate testing either
> vented loop.
>
>
>
> I have to add that I never had a problem in twenty years of ownership and
> ingnored these items until I started replacing hoses.  I'd be glad to hear
> anyone else's ideas on this.
>
>
>
> Chuck S
>
>
>
>
>
>
>

Stus-List Re: vented loops

[John Read via CnC-List]

Interesting – have not heard or seen vented loops used this way.  My 34 does 
not have them and no problems in 40 years

 

John Read

Legacy III

1982 C 34

Noank, CT

 

From: CHARLES SCHEAFFER via CnC-List [mailto:cnc-list@cnc-list.com] 
Sent: Wednesday, June 29, 2022 5:20 PM
To: CNC boat owners, cnc-list
Cc: CHARLES SCHEAFFER
Subject: Stus-List vented loops

 

Learned the hard way how to test vented loops. 

 

I was changing engine hoses and came upon an original, 33 year old, bronze, 
vented loop for the engine cooling water.  It's located between the heat 
exchanger and the injection elbow of the exhaust riser.  It's purpose is to 
break a siphon and prevent water flooding the engine and the boat when the 
engine is off.  Mine was filled with scale and no longer operational.  

 

The following comes from info included with a new Forespar vented loop.  To 
test a vented loop, you blow air through the vent from outside into the tubing, 
through the "duck bill" rubber thing, and that's it.  If air won't penetrate, 
it's clogged and should be cleaned.  If the thing leaks, it probably needs 
cleaning or a new rubber duck bill. 

 

I replaced the Forespar rubber duckbill, $15, on my bilge pump hose and I 
replaced the entire loop fitting $44 on the engine hose using a Forespar 5/8" 
vented loop.  Now both of my vented loops use the same duckbill vent and have 
the same size retaining nut so a simple clear two foot length of 3/4" hose can 
be pushed over the fitting to facilitate testing either vented loop. 

 

I have to add that I never had a problem in twenty years of ownership and 
ingnored these items until I started replacing hoses.  I'd be glad to hear 
anyone else's ideas on this.

 

Chuck S