Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 01-03-2013, 08:41   #1
Registered User
 
Dulcesuenos's Avatar

Join Date: Dec 2010
Location: Western Caribbean
Boat: 38/41 Fountains pajot
Posts: 3,004
Images: 4
Siphon Break Needed?

I have a Siphon break (Scot Pump VL 10) mounted way above waterline , between our Raw water strainer and our water pump">raw water pump; for the Heat exchanger/ cooling system.
Have heard from a few people this is not needed. Our stainless siphon break is starting to weep and I either need to replace it or eliminate it.

The Forespar Marelon ones are more for sanitation and need a pump before them. The type I have are not easy to find, but if not neeeded then why replace it , I could just bypass.
Any advice would be great!
__________________

Dulcesuenos is offline   Reply With Quote
Old 01-03-2013, 08:44   #2
Registered User

Join Date: Feb 2013
Location: Rio Dulce, Guatemala
Boat: Seafarer36c
Posts: 5,369
Re: Siphon Break Needed?

I did not think you are supposed to have a siphon break before the engine just after.
__________________

Ecos is offline   Reply With Quote
Old 01-03-2013, 09:04   #3
Senior Cruiser
 
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Philippines until May
Boat: Boatless Now
Posts: 10,994
Images: 122
Re: Siphon Break Needed?

Here's how it should be set up!





OR........

__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
The measure of a man is how he navigates to a proper shore in the mist of a storm!
delmarrey is offline   Reply With Quote
Old 01-03-2013, 09:11   #4
Registered User

Cruisers Forum Supporter

Join Date: May 2011
Location: Miami Florida
Boat: Ellis Flybridge 28
Posts: 3,610
Re: Siphon Break Needed?

A siphon break (vented loop) should not be used in a suction hose as it is designed to let air into the line. This reduces the ability of the pump to create a vacuum and suck water. Siphon breaks should only be used on the discharge side of a pump.
__________________
Retired from Hopkins-Carter Marine Supplies
HopCar is offline   Reply With Quote
Old 01-03-2013, 10:00   #5
Registered User
 
Dulcesuenos's Avatar

Join Date: Dec 2010
Location: Western Caribbean
Boat: 38/41 Fountains pajot
Posts: 3,004
Images: 4
Re: Siphon Break Needed?

Quote:
Originally Posted by HopCar View Post
A siphon break (vented loop) should not be used in a suction hose as it is designed to let air into the line. This reduces the ability of the pump to create a vacuum and suck water. Siphon breaks should only be used on the discharge side of a pump.
This is what I thought, I couldnt understand why there is one where it is. Our exhaust elbow, and most of the hose is above waterline, so there is no suction or vented loop on that side, could that make a difference? I cant see how it would?
Dulcesuenos is offline   Reply With Quote
Old 01-03-2013, 17:06   #6
Registered User

Join Date: Feb 2013
Location: Rio Dulce, Guatemala
Boat: Seafarer36c
Posts: 5,369
Re: Siphon Break Needed?

I think I would have a siphon break if there was even a question about the exhaust going downhill from the engine. In big seas who knows what angle your exhaust might be. I cannot think what disadvantage a siphon break could have in the heat exchanger output line. As for the the snifter valve clogging, leave it out. Run a small hose ovbd. Incidentally, if you place the thru hull for the vented overboard loop in a nice place, it lets you check on your water temp etc. with your fingers, very nice feature.
Ecos is offline   Reply With Quote
Old 01-03-2013, 17:16   #7
Registered User
 
svHyLyte's Avatar

Join Date: Mar 2006
Location: Tampa Bay area, USA
Boat: Beneteau First 42
Posts: 3,868
Images: 25
Re: Siphon Break Needed?

Quote:
Originally Posted by Dulcesuenos View Post
I have a Siphon break (Scot Pump VL 10) mounted way above waterline , between our Raw water strainer and our raw water pump; for the Heat exchanger/ cooling system.
Have heard from a few people this is not needed. Our stainless siphon break is starting to weep and I either need to replace it or eliminate it.

The Forespar Marelon ones are more for sanitation and need a pump before them. The type I have are not easy to find, but if not neeeded then why replace it , I could just bypass.
Any advice would be great!
The preferred position for a siphon break in a raw water feed circuit is between the raw water pump and the heat exchanger. Works every time.

FWIW...
__________________
"It is not so much for its beauty that the Sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."
svHyLyte is offline   Reply With Quote
Old 01-03-2013, 17:24   #8
Registered User

Join Date: Feb 2013
Location: Rio Dulce, Guatemala
Boat: Seafarer36c
Posts: 5,369
Re: Siphon Break Needed?

I think to have a vented loop before the heat exchanger it would to have been in the original design of the engine. In something like a Perkins say, the cooling water plumbing does not become accessible until after the heat exchanger. It does sound like a better system though, maybe.
Ecos is offline   Reply With Quote
Old 01-03-2013, 18:22   #9
Registered User

Join Date: Dec 2009
Posts: 2,959
Images: 4
My PO did that on the head intake: siphon break before the pump. But because that caused the head to not flush he simply plugged the little leak in the siphon break. Hilarious.
__________________

daddle is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 05:33.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.