Hi All, Can anyone tell me where I can get a replacement vacuum breaker/anti-siphon valve that screws onto the stainless steal “U” shaped tube? It attaches to the hose between the raw water heat exchange and exhaust elbow. It’s made of plastic and has a 3/8 female pipe thread. Thanks, Joe
Raw water vacuum breaker/anti-siphon valve
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Anti Siphon
I have thought about this and must admit I have not tried it. But it seems to me that all this is is a check valve. So, a 3/8" check valve at the Home Depot or Lowes, would cost about 1/10 the cost of basically the same thing at a boat store.
I have thought about this and must admit I have not tried it. But it seems to me that all this is is a check valve. So, a 3/8" check valve at the Home Depot or Lowes, would cost about 1/10 the cost of basically the same thing at a boat store.
Anti-siphon
My boat has an anti-siphone valve, not a check valve. It is there to stop the siphoning effect of water through the heat exchanger and into the exhaust system, which would eventually fill and flow back into the engine. Good Luck Greg
My boat has an anti-siphone valve, not a check valve. It is there to stop the siphoning effect of water through the heat exchanger and into the exhaust system, which would eventually fill and flow back into the engine. Good Luck Greg
Uh, try West Marine
I am sure that there have to chandlereys near you, too, in addition to WM. If it's off, take it in with you and show them what you need.
I am sure that there have to chandlereys near you, too, in addition to WM. If it's off, take it in with you and show them what you need.
My ignorance
In my ignorance I fail to see the difference between an anti siphon valve and a check valve. Is not the purpose of an anti siphon to make a vent to stop the water from coming back via a siphon. A check valve that is turned to let air in and no water out should be the exact same thing, with just a different name. Can someone tell me where I am not getting it.
In my ignorance I fail to see the difference between an anti siphon valve and a check valve. Is not the purpose of an anti siphon to make a vent to stop the water from coming back via a siphon. A check valve that is turned to let air in and no water out should be the exact same thing, with just a different name. Can someone tell me where I am not getting it.
Easy...
check valves are usually found in-line in a hose to prevent the reversal of flow, such as for keeping prime on a manual galley faucet. It has no air connection and works like one of the flaps that open and close in a manual bilge pump. An anti-siphon valve prevents water from continuing to flow in a hose without suction being applied, flooding a boat--such as in a raw water intake line for the head or engine. It could be a valve like a head's joker (a "duckbill" type), or it could be a ball valve in a seat that seals under suction. It's located at the top of a horseshoe-like loop in a "T" fitting that's open on one end to the outside air. It's normally closed when suction is applied by a pump (head, raw water engine), but will un-seal to admit air and stop flow if water tries to continue to flow past it once suction is removed from the on-board end. That's my attempt to simplify the answer. Hope it clarifies it for you.
check valves are usually found in-line in a hose to prevent the reversal of flow, such as for keeping prime on a manual galley faucet. It has no air connection and works like one of the flaps that open and close in a manual bilge pump. An anti-siphon valve prevents water from continuing to flow in a hose without suction being applied, flooding a boat--such as in a raw water intake line for the head or engine. It could be a valve like a head's joker (a "duckbill" type), or it could be a ball valve in a seat that seals under suction. It's located at the top of a horseshoe-like loop in a "T" fitting that's open on one end to the outside air. It's normally closed when suction is applied by a pump (head, raw water engine), but will un-seal to admit air and stop flow if water tries to continue to flow past it once suction is removed from the on-board end. That's my attempt to simplify the answer. Hope it clarifies it for you.
anit-siphon or check valve
a check valve in a line is not an anti-siphon device. It just insures the water flows in only one direction A check valve Tee(ed) into a U-shaped tube and placed so it is above the water line is. The one way valve keeps the water from coming out. But once the water stops flowing and there is only static pressure in the line the check valve opens and lets air in allowing the water to either drain into the exhaust pipe or back into the engine. And since water can not flow up hill no water enters the boat.
a check valve in a line is not an anti-siphon device. It just insures the water flows in only one direction A check valve Tee(ed) into a U-shaped tube and placed so it is above the water line is. The one way valve keeps the water from coming out. But once the water stops flowing and there is only static pressure in the line the check valve opens and lets air in allowing the water to either drain into the exhaust pipe or back into the engine. And since water can not flow up hill no water enters the boat.
It's still the same thing
So according to Dan's post a check valve and an anti siphon valve are the same thing, just used in a different location/position. A check valve installed in a upside down U becomes an anti siphon valve. They do he same thing, just called by different names when used for different applications.
So according to Dan's post a check valve and an anti siphon valve are the same thing, just used in a different location/position. A check valve installed in a upside down U becomes an anti siphon valve. They do he same thing, just called by different names when used for different applications.
Hunter Marine
I got a replacement anti-siphon valve from Hunter Marine about two years ago. Give them a call to see if they still have any. Hunter Marine - Parts 800-771-5556 x 3015
I got a replacement anti-siphon valve from Hunter Marine about two years ago. Give them a call to see if they still have any. Hunter Marine - Parts 800-771-5556 x 3015
Thanks All
Thanks for all the GR8 info! I took the plastic valve off and cleaned it and it seems to be working at the moment. I would still like to get a spare just in case. I called Hunter but haven't got an answer yet. Joe
Thanks for all the GR8 info! I took the plastic valve off and cleaned it and it seems to be working at the moment. I would still like to get a spare just in case. I called Hunter but haven't got an answer yet. Joe
Nice...
I think you missed the point. If you put a check valve in where you should have an anti-siphon device you could sink your boat! It will prevent back flow, but not stop a siphoning, which is a continued flow in the same direction as normal that doesn't stop when it should. Good Luck!
I think you missed the point. If you put a check valve in where you should have an anti-siphon device you could sink your boat! It will prevent back flow, but not stop a siphoning, which is a continued flow in the same direction as normal that doesn't stop when it should. Good Luck!
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